The neurons in the robust nucleus of the archistriatum (RA) encode each note; they are activated by RA-projecting neurons in the HVC (used as a proper name). 
During 5-30 day after BrdU intramuscular injection, some of labeled cells emerged into the nucleus of high vocal center (HVc), and robust nucleus of the archistriatum (RA) in Melanocorypha mongolica.
In songbirds, signals generated in nucleus High Vocal center (HVc) follow a direct route along a premotor pathway to the robust nucleus of the archistriatum (RA) as well as an indirect route to RA through the anterior forebrain pathway (AFP): the neurons of RA are innervated from both sources.
Electrophysiological recordings in the robust nucleus of the archistriatum (RA) in adult zebra finch brain slices reveal that tetanic stimulation alone does not produce LTP.
Elevated levels of SNAP-25 mRNA were present in the nucleus hyperstriatalis ventrale pars caudale (HVC) and in the robust nucleus of the archistriatum (RA).
The sectors of the hyperstriatum composing the Wulst (i.e., the hyperstriatum accessorium intermedium, and dorsale), the hyperstriatum ventrale, the neostriatum, and the archistriatum have been renamed (respectively) the hyperpallium (hypertrophied pallium), the mesopallium (middle pallium), the nidopallium (nest pallium), and the arcopallium (arched pallium). The posterior part of the archistriatum has been renamed the posterior pallial amygdala, the nucleus taeniae recognized as part of the avian amygdala, and a region inferior to the posterior paleostriatum primitivum included as a subpallial part of the avian amygdala.
Using a computational model of the song motor pathway and the songbird vocal organ, we investigate the relationship between song production and the neural connectivity of nucleus HVc (used as a proper name) and the robust nucleus of the archistriatum (RA).
No direct connections were identified between the POM and song control nuclei; however, labeled fibers were found to terminate in a region bordering dorsal-medial portions of the robust nucleus of the archistriatum (RA).
Numerous CRF-ir perikarya and fibers were present in the hyperstriatum, hippocampus, neostriatum, lobus parolfactorius, and archistriatum, as well as in the nucleus taeniae, nucleus accumbens, and bed nucleus of the stria terminalis, which exhibited the strongest immunolabeling in the telencephalon.
Expression was also found in many areas of the hypothalamus and dorsal thalamic nuclei, nucleus intercollicularis and ventricular areas of the midbrain, cerebellar Purkinje and granule cells, the hyperstriatum, medial neostriatum, medial LPO, and archistriatum. In juvenile males, AR mRNA expression was first detected in nucleus high vocal center (HVC) at posthatch day 9 (P9), in area X at P9-P11, and in the region of the robust nucleus (RA) in the medial archistriatum by P7.
areas flanking the primary telencephalic auditory field (i.e., fields L2b, L1, and L3) and areas surrounding the robust nucleus of the archistriatum (RA); 2).
The main targets of septal projections comprised the ipsi- and contralateral septal nuclei, including the nucleus of the diagonal band, basal ganglia, including the ventral paleostriatum, lobus parolfactorius, nucleus accumbens, and olfactory tubercle, archistriatum, piriform cortex, and anterior neostriatum.
To understand how multiple factors interact to coordinate reproductive activity we explored relationships among social status, badge size, gonad volume, and the volumes of brain regions involved in male courtship and dominance (HVC, robust nucleus of the archistriatum, and the medial preoptic nucleus).
Overall Leu incorporation was increased by T in five brain regions, many of which contain sex steroid receptors such as the POM, archistriatum and lateral hypothalamus.
RESULTS: At 180 days, apparent diffusion coefficient (ADC) values in the optic tectum and archistriatum of the stimulated epileptic chicks were reduced, whereas ADC values in the nonstimulated group remained unchanged.
The results indicate that: 1) Substance P labeled terminal and part cells were distributed in the Area X; 2) Substance P labeled cells were distributed in the nucleus high vocal center (HVc), magnocellular nucleus of the anterior neostriatum (MAN), robust nucleus of the archistriatum (RA) and dorsolateral nucleus of the anterior thalamus (DLM); 3) Substance P labeled terminal and fibers were distributed in the vocal control nuclei such as nucleus dorsalis medialis (DM) and the nucleus hypoglossi, pars tracheosyringealis (nXI-Its), and in the auditory nuclei such as the nucleus ovidalisashell (Ov shell), the shell regions of mesencephalicus lateralis, pars dorsalis (MLd shell) and the nucleus intercollicularis (ICo).
After 37 days of exposure to sex steroids, we measured the volumes of the forebrain song nucleus HVc, the robust nucleus of the archistriatum (RA), and a basal ganglia homolog (area X).
The eta, epsilon, and trace values in the hyperstriatum, archistriatum, and optic tectum showed significant changes as a function of developmental time point. Differences and/or interactions due to seizures were seen in the archistriatum and optic tectum for eta, epsilon, and trace with the largest differences between the stimulated and unstimulated birds being seen for eta in juvenile birds in the archistriatum (38.1 x 10(-11) m(2)/s versus 18.0 x 10(-11) m(2)/s) and the optic tectum (53.9 x 10(-11) m(2)/s versus 27.1 x 10(-11) m(2)/s).
A possible relationship was also detected between female preferences for male spring compared to fall song and the volume of the robust nucleus of the archistriatum.
In addition, stimulation in the squirrel wheel was accompanied by high levels of c-fos expression in the paraolfactory lobes, while sound stimulation gave high levels of c-fos expression in the ventral and caudal parts of the archistriatum.
The archistriatum mediates a neural pathway from the medial part of intermediate hyperstriatum ventrale (in the dorsal pallium) to the lobus parolfactorius (in the medial striatum), thus is possibly involved in memory formation in the domestic chick. To elucidate the functional roles, we examined single neuron activities from archistriatum in unconstrained chicks during execution of a GO/NOGO task. The ventral part of intermediate archistriatum proved to contain a group of neurons that selectively responded to the reward-associated colours before the reward was actually presented, possibly coding the memorized associations. It is concluded that even a subregion of archistriatum contains diverse neural codes for memorized associations and food rewards, and neural codes of movements cued by sounds, suggesting that archistriatum is a complex of different functional systems, possibly corresponding to striatum, limbic amygdala, and prefrontal cortex in mammals..
We will stress that common brain regions are shared by these distinct paradigms, particularly those in the ventral telencephalic structures such as AIv (in the archistriatum) and LPO (in the medial striatum).
This coincidence is found in areas of the avian ventral and lateral pallium (ventral hyperstriatum, neostriatum, and ectostriatum) and in a part of the archistriatum, which is of pallial origin.
It induces the expression of protein kinase C (PKC) which is related to the plasticity in the robust nucleus of the archistriatum (RA), one of the song control nuclei in the forebrain.
Anatomical tracing of the vocal control system shows that DM neurons of adult males receive axonal inputs from the robust nucleus of the archistriatum (RA), and the inputs are considered to be crucial for the male-typical features of distance calls.
HVc projection neurons were identified by electrically stimulating HVc's target nuclei, the robust nucleus of the archistriatum and Area X, in anesthetized zebra finches.
We present a model for the activities of neural circuits in a nucleus found in the brains of songbirds: the robust nucleus of the archistriatum (RA).
AR mRNA was also detected in the hippocampus, neostriatum, septum, ventromedial archistriatum, hypothalamic regions, dorsal mesencephalon, and in and around the brainstem nucleus tracheosyringealis.
HVC neurons projecting to the robust nucleus of the archistriatum (HVC-RA) were retrogradely labeled with Fluoro-Gold 4 d before death.
From posthatching day (PHD) 20-63 in males but not females, RA and its input nucleus HVc showed sharp increases in cytochrome oxidase (CO) activity relative to surrounding archistriatum and the underlying shelf, respectively.
The archistriatum pars ventrolateralis (Avl; comparable to the pigeon archistriatum pars dorsalis) is theorized to be a possible homologue of the central amygdaloid nucleus.
In this study, whole cell patch clamp recordings were made from neurons in the robust nucleus of the archistriatum (RA), which is a motor control nucleus of male-specific vocalization in male birds of different developmental stages.
In HVc (sometimes called the High Vocal Center) and the robust nucleus of the archistriatum (RA), there is a higher density of CBP-ir cells within the boundaries of these nuclei than in adjacent neostriatum or archistriatum, for HVc and RA, respectively.
Neurochemical, hodological and functional criteria suggest that the nucleus taeniae and parts of the adjacent archistriatum represent the avian homologue of parts of the mammalian amygdaloid complex. In male quail, relatively large lesions to the posterior/medial archistriatum selectively decrease the expression of appetitive sexual behavior in a manner reminiscent of similar manipulations involving the medial amygdala in mammals. We investigated the effects of discrete lesions restricted to nucleus taeniae and of lesions to an adjacent part of the archistriatum (pars intermedium ventralis, AIv) on the expression of appetitive (ASB) and consummatory (CSB) aspects of male sexual behavior.
In songbirds, one prominent site of pre-motor activity is the forebrain robust nucleus of the archistriatum (RA), which generates stereotyped sequences of spike bursts during song and recapitulates these sequences during sleep.
In contrast, degenerating cells were never observed in the archistriatum or sub-telencephalic regions, suggesting that excess T4 augments cell death selectively in regions that show naturally occurring neuronal turnover.
Neural input from the robust nucleus of archistriatum (RA) was observed in the DM of sexually mature males, but not observed in that of sexually mature females.
In males, dense alpha(2)-receptors were observed in the song system (Area X, the high vocal center (HVc), the lateral portion of the magnocellular nucleus of the anterior neostriatum, and the robust nucleus of the archistriatum). The robust nucleus of the archistriatum contained less dense alpha(2)-binding in females compared to males.
Two other imprinting-related areas, the medial neo/hyperstriatum ventrale (MNH) and archistriatum/neostriatum caudale (ANC), do show c-fos induction; however, the areas are not congruous with those demarcated by the 2-DG autoradiographic studies.
To clarify what kind of changes appear in the brain of deafened birds, we examined immunohistochemically the expression of protein kinase C (PKC), considered a molecular marker for synaptic plasticity, in the robust nucleus of the archistriatum (RA), one of the song control nuclei in the forebrain of finches.
In contrast, the dorsal part of the archistriatum intermedium, the nucleus taeniae, a medial part of the lobus parolfactorius and the dorsomedial part of the hippocampus displayed an extremely dense serotonergic innervation. The high accumulation of 5-HT+ fibers in the dorsal part of the archistriatum intermedium points to a prominent role for 5-HT in fear behavior..
A posterior "motor pathway" including nucleus HVc (used as the proper name), the robust nucleus of the archistriatum (RA) and descending projections to the brainstem, is essential for song production.
Using the same criteria, the caudal neostriatum and the ventral intermediate archistriatum may represent the ventral pallial amygdala of birds. In the avian brain, the same embryological, hodological, and histochemical criteria are met by the area temporo-parieto-occipitalis, the caudolateral neostriatum and the dorsal intermediate archistriatum.
Priming in the running wheel additionally induced c-fos expression in the lobus parolfactorius, while priming by acoustic stimulation produced high c-fos expression in the archistriatum.
Song nuclei (the high vocal center [ HVc], robust nucleus of the archistriatum [ RA], and Area X) were largest, T was highest, and the density of alpha(2) adrenergic receptors (within HVc and RA) was lowest during the breeding season.
However, topographic organization within the projection from the core subregion of lMAN (lMAN(core)) to the motor cortical robust nucleus of the archistriatum (RA) is lacking at the onset of song development and emerges during the early stages of vocal learning.
Study of the nonoscine brain has revealed a 'general motor pathway' from caudolateral neostriatum (NCL) to intermediate archistriatum (Ai) that resembles the song system motor pathway in its anatomical organization.
Immunoreactivity was exhibited by telencephalic nuclei previously associated with vocal control pathways on the basis of both tract tracing studies and gene mapping: the central nucleus of the anterior archistriatum (AAc), central nucleus of the lateral neostriatum (NLc), magnocellular nucleus the lobus parolfactorius (LPOm), the oval nucleus of the ventral hyperstiratum (HVo) and the medial division of the oval nucleus of the anterior neostriatum (NAom).
GnRH content was assessed by immunocytochemistry and the volumes of Nissl-defined song-control nuclei (HVc, Area X, and the robust nucleus of the archistriatum) were reconstructed.
Studies utilizing a variety of neurohistological methods in several different species to define the boundaries of two key telencephalic song nuclei HVc and the robust nucleus of the archistriatum (RA) all tend to find a sex difference in volume in agreement with Nissl-defined boundaries.
High induction of immediate early genes occurs in hypothalamic and limbic areas such as the medial preoptic nucleus, bed nucleus striae terminalis and parts of the archistriatum in birds who had copulated and/or who had expressed a learned social proximity response, reflecting appetitive sexual behavior.
All of the forebrain song nuclei, including the high vocal centre (HVC), the robust nucleus of the archistriatum (RA), Area X and the lateral and medial magnocellular nuclei of the anterior neostriatum (lMAN and mMAN) were found to be well developed in both male and female magpies.
NPY-ir neurons were seen in the lobus parolfactorius; hyperstriatum, neostriatum, paleostriatum, and archistriatum; hippocampal and parahippocampal areas; dorsolateral corticoid area; piriform cortex; two thalamic areas contiguous to the n.
Extracellular recordings were made in normal and device-reared owls to characterize frequency-specific ITD and ILD tuning in the auditory archistriatum (AAr), an output structure of the forebrain localization pathway.
The expression was also localized in the septum, the hyperstriatum accessorium, and the ventral portions of the archistriatum in the telencephalon.
Other sources of input to the HVo surround include the hyperstriatum accessorium (HA), the supralaminar area of the frontal neostriatum (NAs), the ventral anterior archistriatum (AAv), the medial archistriatum (Am) and the medial HV.
In both LD+T groups, the direct efferent targets of HVc, the robust nucleus of the archistriatum (RA) and area X, were smaller ipsilateral to the lesion.
The other motor center, the medial part of the anterior archistriatum, was proved to be directly connected to the ectostriatal core as well. Considering that the archistriatum is also connected indirectly to the Wulst, the movements are able to be guided by well processed visual information..
Neurons in lMAN(core) project to a region of motor cortex known as robust nucleus of the archistriatum (RA), whereas neurons in lMAN(shell) project to a region adjacent to RA known as dorsal archistriatum (Ad).
The two main song control nuclei in the zebra finch forebrain, the higher vocal center (HVC) and the robust nucleus of the archistriatum (RA), receive cholinergic innervation from the ventral paleostriatum (VP) of the basal forebrain which may play a key role in song learning.
The results show that TH staining in the central nucleus of the anterior archistriatum (AAc) resembled that of surrounding archistriatal fields, except for portions of the ventral archistriatum, which exhibited substantially more TH+ fibers. Several unique features of TH-immunoreactive (ir) cell groups were observed in the brainstem including sparsely scattered TH-ir somata immediately adjacent to the third ventricle, within the tectum, basal forebrain, archistriatum, and caudal neostriatum, and in the hippocampus.
Here we characterize the developmental expression of zenk mRNA and protein in two forebrain song regions (HVC, the higher vocal center, and RA, the robust nucleus of the archistriatum).
Labeling for D1A receptor mRNA was intense in the medial and lateral striatum, and moderately abundant in the pallial regions termed the archistriatum and the neostriatum, in the hypothalamic paraventricular nucleus region, and in the superficial gray layer of optic tectum of the midbrain. The data suggest that while both D1A and D1B receptors mediate dopaminergic responses in many neurons of the avian striatum, primarily D1A receptors mediate dopaminergic responses in the archistriatum and the neostriatum, while primarily D1B receptors mediate dopaminergic responses in the hyperstriatum ventrale and the thalamus..
The model focuses on the motor nuclei HVc and robust nucleus of the archistriatum (RA) of zebra finches and incorporates the long-standing hypothesis that a series of song nuclei, the Anterior Forebrain Pathway (AFP), plays an important role in comparing the bird's own vocalizations with a previously memorized song, or "template." This "AFP comparison hypothesis" is challenged by the significant delay that would be experienced by presumptive auditory feedback signals processed in the AFP.
The two main song control nuclei in the forebrain of zebra finches, the higher vocal center (HVC) and the robust nucleus of the archistriatum (RA), are sexually dimorphic at many levels of their neural circuitry.
The avian subpallium, called "paleostriatum," shows nested Dlx-2 and Nkx-2.1 domains and migrated Pax-6-positive neurons; the avian pallium expresses Pax-6, Tbr-1, and Emx-1 and also contains a distinct Emx-1-negative ventral pallium, formed by the massive domain confusingly called "neostriatum." These expression patterns extend into the septum and the archistriatum, as they do into the mouse septum and amygdala, suggesting that the concepts of pallium and subpallium can be extended to these areas.
The high vocal center (HVC) controls song production in songbirds and sends a projection to the robust nucleus of the archistriatum (RA) of the descending vocal pathway.
Labeling in somata and neuropil appeared to define the telencephalic components of the motor pathway (high vocal center and robust nucleus of the archistriatum) for song production in males from days 30 to 60, and in females on days 45 and 60 (high vocal center).
Some of these axon-like fibers extend into the high vocal center (HVC) and the robust nucleus of the archistriatum (RA) in males and females, suggesting a role for presynaptic aromatization in cellular processes within these loci.
The motor output of telencephalic song processing is RA (the robust nucleus of the archistriatum), a region containing a population of projection neurons that descend to the hindbrain (nXIIts, the tracheo-syringeal portion of the hypoglossal nerve nucleus).
The telencephalic areas where the most intense signals for PACAP mRNA were found included the hyperstriatum accessorium, the hippocampus, and the archistriatum.
The performance of copulation and/or appetitive sexual behavior increased the number of Fos-immunoreactive cells in the ventral hyperstriatum, medial archistriatum, and nucleus striae terminalis.
The telencephalon contained CGRPi fibres within the paleostriatal complex (mainly in the ventral paleostriatum), parts of the neostriatum and ventral hyperstriatum, parts of the archistriatum, and the septum.
Areas with densely packed GRP-ir clusters of varicosities were the medial intermediate hyperstriatum ventrale and lateral septal nucleus; dense GRP-ir neuropil was found in the parolfactory lobe, and in the dorsal half of the intermediate and caudal archistriatum. Forebrain areas devoid of immunoreactivity were the basal nucleus, ectostriatum, rostral archistriatum, most of the paleostriatum augmentatum and the lateral bed nucleus of the stria terminalis.
We studied the effects of both unilateral and bilateral lesions of the central nucleus of the anterior archistriatum (AAc) on the production of contact calls and warble song in adult male and female budgerigars.
Moreover, among the subset of HVc vocal motor neurons that project to the robust nucleus of the archistriatum, the incidence of [ (3)H]thymidine-labeled neurons was nearly three times as great in bengalese than in zebra finches.
In addition, some neurones in the archistriatum were double-labelled, which indicates that these archistriatal neurones have axon collaterals projecting to the visual Wulst on both sides of the forebrain.
As zebra finch caudal telencephalon contains the higher vocal center (HVC) and the robust nucleus of the archistriatum (RA), regions involved in song learning and production, we further investigated CB1 expression in these areas using in situ hybridization.
Bilateral lesions targeting the central nucleus of the anterior archistriatum (AAc) were placed in nestling budgerigars (Melopsittacus undulatus) aged 5, 9, 13, 22, 26, and 33 days post-hatch in order to evaluate the role of the telencephalon in producing nestling vocalizations in this species. The results show that lesions destroying AAc bilaterally in addition to surrounding archistriatum and neostriatum do not alter the production of early simple patterned foodbegging calls but do prevent both the normal transition at 3-4 weeks post-hatch to more complex begging calls as well as the emergence of individually-distinctive contact calls around the time of fledging.
Memory formation for a passive avoidance task in the domestic chick is likely to involve a hyperstriatum ventrale (IMHV)-archistriatum-lobus parolfactorius (LPO) arc. Projections from the IMHV on the archistriatum, as well as from the archistriatum on the LPO, have been characterised using a combination of anterograde pathway tracing (Phaseolus lectin), and post-embedding GABA and glutamate immunocytochemistry. The majority of IMHV efferents have been found to synapse with dendritic spine heads and necks of densely spiny projection neurons of the ventral archistriatum, and the ultrastructure of synapses suggested a potent excitatory input. Although some of the IMHV boutons terminating in the archistriatum were immunoreactive to glutamate, this was not observed in the archistriatal-LPO pathway. Learned visual association with the target (bead) occurs in the IMHV and is relayed to the basal ganglia via the limbic archistriatum (amygdala equivalent), the latter introducing a motivational element (aversion, fear).
The DL region could be paralleled to the subiculum of mammals with its main projections to the basal ganglia, the limbic archistriatum, the lateral septum and the paraxial meso-diencephalic centres.
Our findings revealed developmental regulation of both mRNAs in the neostriatum, archistriatum, hippocampus, diencephalon and midbrain. Within the vocal control circuitry, cells expressing ERalpha mRNA were found in the medial HVC (P10-25), archistriatum lateral to the RA (Ad; P25), in the ICo (P5-25), and along the fiber tract containing efferents from the RA. High levels of AROM mRNA were found in the neostriatum, including both the lateral and mMAN and along their projections to the RA and HVC, respectively, (P5-25), in the archistriatum (P18-25) and around RA (P18).
In free-living adult dark-eyed juncos (Junco hyemalis), a species in which females do not normally sing, the sizes of three VCRs (high vocal center, robust nucleus of the archistriatum, and Area X) were larger in males than females and decreased between summer and fall in both sexes.
Efferent targets of HVC, the robust nucleus of the archistriatum (RA), and area X of the parolfactory lobe grew more slowly and were not significantly larger until day 20 of the study.
This was true for all [ (3)H]-labeled HVC neurons, as well as the subset that projected to the robust nucleus of the archistriatum.
Electrical stimulation to higher vocal center (HVC) fibers induced within 20 ms neural activities in the robust nucleus of the archistriatum (RA) of both male and female finches, although the amplitude was smaller and the latency was greater in females than in males.
We sought to determine whether one action of androgens is to functionally modulate the development of synaptic transmission in two brain nuclei, the lateral part of the magnocellular nucleus of the anterior neostriatum (LMAN) and the robust nucleus of the archistriatum (RA), that are critical for song learning and production.
Although these age-limited behavioral effects implicate LMAN in song learning, a potential confound is that LMAN lesions could disrupt normal vocal motor function independent of any learning role by altering LMAN's premotor target, the song nucleus, the robust nucleus of the archistriatum (RA).
Sexual interactions significantly induced FLI cells in the hyperstriatum ventrale, the part of the archistriatum just lateral to the anterior commissure, and the nucleus intercollicularis.
Similar to reports in other songbird species, we detected AR mRNA-containing cells in several song control nuclei, including the high vocal center (HVc), the medial and lateral portions of the magnocellular nucleus of the anterior neostriatum, and the robust nucleus of the archistriatum. ER beta was not expressed in HVc, in the medial and lateral portions of the magnocellular nucleus of the anterior neostriatum, in the robust nucleus of the archistriatum, or in area X.
Here, we show that the HA also is the origin of a set of intratelencephalic projections with terminal fields in the lateral part of the frontal neostriatum, the shell surrounding the lateral magnocellular nucleus of the anterior neostriatum, the lobus parolfactorius surrounding area X, the nucleus interface, auditory fields L1 and L3, the shelf underlying the high vocal center, the dorsolateral caudal neostriatum, the dorsocaudal part of the nucleus robustus archistriatalis, and the ventral archistriatum.
Nucleus taenia (Tn) in birds is a discrete component of a loosely defined archistriatal structure, the posterior and medial archistriatum. By virtue of its hypothalamic projections, the posterior and medial archistriatum is thought to be an avian homolog of the amygdala in mammals.
By 8 days, some [ (3)H]-labeled cells with the nuclear profile of postmigratory neurons were already present in HVC but could not be retrogradely labeled by Fluoro-Gold injections in the robust nucleus of the archistriatum (RA); 7 days later, a few such cells could be backfilled from RA.
The population of HVc cells expressing BDNF mRNA included 35% of the neurons projecting to the nucleus robustus of the archistriatum (RA).
The zebra finch forebrain song control nucleus RA (robust nucleus of the archistriatum) generates a phasic and temporally precise neural signal that drives vocal and respiratory motoneurons during singing.
The nuclei investigated were the hypoglossal nucleus, dorsomedial nucleus of the intercollicular midbrain, central nucleus of the archistriatum, central nucleus of the lateral neostriatum, oval nucleus of the hyperstriatum ventrale, medial division of the oval nucleus of the anterior neostriatum, and magnocellular nucleus of the lobus parolfactorius. At hatching the hypoglossal nucleus exhibits adult-like cytoarchitecture, and the central nucleus of the archistriatum and the central nucleus of the lateral neostriatum are distinguishable from surrounding fields. By one week posthatch, the central nucleus of the archistriatum exhibits an adult-like appearance, while other telencephalic vocal control nuclei do not exhibit adult-like cytoarchitecture until three to four weeks posthatching.
The avian subpallium -the paleostriatum- expresses Dlx-2 and Nkx-2.1; expression extends as well into the septum and anterior and medial parts of the archistriatum. The avian pallium expresses Pax-6, Tbr-1 and Emx-1 and also contains a distinct ventral pallium, formed by the neostriatum and ventral intermediate parts of the archistriatum. The lateral pallium comprises the hyperstriatum ventrale, overlying temporo-parieto-occipital corticoid layer and piriform cortex, plus dorsal intermediate and posterior archistriatum. Ventral pallial derivatives identified as claustroamygdaloid in the mouse correlate with avian neostriatum and parts of the archistriatum..
Intense gastrin releasing peptide (GRP)-immunoreactivity was found in the neuropil of LPO, the ventral paleostriatum and the caudal archistriatum; further GRP-immunoreactive varicosities were found in the neostriatum and the hyperstriatum ventrale - particularly in its medial part - whereas GRP-immunoreactive cells occurred in the medial neostriatum, the hyperstriatum accessorium and the ventral archistriatum.
By using antero- and retrograde pathway tracing techniques, we investigated the organization of sensory afferents to the NCL and the connections with limbic and somatomotor centers in the basal ganglia and archistriatum. Projections to the archistriatum are mainly directed to the somatomotor part of the intermediate archistriatum. In addition, cells in caudal NCL were found to be connected with the ventral and posterior archistriatum, which are considered avian equivalents of mammalian amygdala.
A part of the archistriatum intermedium and the lateral part of the neostriatum caudale also received somewhat minor projections. In addition, some neurons in Ec were also the source of direct, but minor, projections to the NFL, TPO, NIL, and archistriatum intermedium.
The two main song control nuclei in the zebra finch forebrain, the higher vocal center (HVC) and the robust nucleus of the archistriatum (RA), receive cholinergic innervation from the ventral paleostriatum (VP) of the basal forebrain which may play a key role in song learning.
Extracellular recordings were used to characterize ITD tuning in the auditory archistriatum (AAr), a subdivision of the forebrain gaze fields, in normal and prism-reared owls.
of the archistriatum (delta and mu), and n.
The lateral part of the hyperstriatum ventrale sent a few efferent fibres toward the diencephalon and brainstem, but projected massively to the ectostriatum periphericum, neostriatum intermedium pars laterale, the ventral part of the neostriatum caudale and the archistriatum dorsale. The neostriatum may be an associative visual center and possibly a modulatory area toward the archistriatum intermedium dorsale, by which visual information may mediate, modulate and control the movements..
The present study focused on one song control area, the robust nucleus of the archistriatum (RA), and explored how sex differences in the proliferation of putative glia cells in this region influence sexually dimorphic cell survival.
One projection, to the robust nucleus of the archistriatum (RA), serves as the primary motor pathway for song production, and can also carry auditory information to RA.
At day 45, the staining in hyperstriatum ventrale, pars caudale was denser than at day 20 and the robust nucleus of the archistriatum, another song nucleus, showed BDNF labeling.
This study examined the relationship between the volumes of four song control nuclei: the high vocal center (HVC), the lateral part of the magnocellular nucleus of the anterior neostriatum (IMAN), Area X, and the robust nucleus of the archistriatum (RA), as well as syrinx mass, with several measures of song output and song complexity in male zebra finches (Taeniopygia guttata).
The axons of some of the neurons in this class projected in the direction of the robust nucleus of the archistriatum (RA).
In adults, all HVC injections produced an even, nontopographic distribution of retrograde label throughout the medial magnocellular nucleus of the anterior neostriatum (mMAN), the interfacial nucleus (NIf), and the uvaeform nucleus of the thalamus (Uva) and an even distribution of anterograde label within area X of the striatum and the robust nucleus of the archistriatum (RA).
In two song nuclei, HVc and the robust nucleus of the archistriatum (RA), the optical disector yielded intergroup differences in neuron density and number that coincided well with the three previous reports.
Here, we examine the connectivity of two previously identified telencephalic stations of the auditory system of adult zebra finches, the neostriatal "shelf" that underlies the high vocal center (HVC) and the archistriatal "cup" adjacent to the robust nucleus of the archistriatum (RA).
dorsolateralis posterior (DLP), both project to the IMHV, and both are reciprocally connected with the archistriatum intermedium (AI).
Nucleus taeniae (Tn) is a prominent cell group within the medial archistriatum of birds.
Among the similarities are the existence of recursive pathways interconnecting vocal control neurons in the archistriatum, basal ganglia (i.e., lobus parolfactorius), and dorsal thalamus. Despite these similarities, the budgerigar dorsal striatopallidum (lobus parolfactorius, paleostriatum augmentatum, and paleostriatum primitivum) and somatomotor (anterior) archistriatum exhibit unique patterns of ELI. The dorsal striatopallidum contained far less ELI, whereas the archistriatum contained far more than would be expected on the basis of previous studies of opioid peptides in other avian species, including pigeons, chickens, and songbirds.
Using standard anatomic labeling techniques, we used a "top-down" approach to trace the flow of auditory spatial information from an output area of the forebrain sound localization pathway (the auditory archistriatum, AAr), back through the forebrain, and into the auditory midbrain.
The representation of binaural cues in Field L suggests that it is involved in auditory space processing but at a lower level of information processing than the auditory archistriatum, a forebrain area that is specialized for processing spatial information, and that the levels of information processing in the forebrain space processing pathway are remarkably similar to those in the well-known midbrain space processing pathway..
NE turnover rates changed significantly over development in all six VCN [ nucleus interfacialis (Nlf), high vocal center (HVC), nucleus robustus of the archistriatum (RA), dorsomedial portion of the intercollicular nucleus (DM), Area X of the parolfactory lobe, and lateral portion of the magnocellular nucleus of the anterior neostriatum (IMAN)]; one AN [ nucleus mesencephalicus lateralis pars dorsalis (MLd)], and one HN [ preopticus anterior (POA)].
In several species song repertoire size correlates with the overall volume of two song-related brain regions, the HVc (acronym used as the proper name) and the robust nucleus of the archistriatum (RA).
Very low ir-ACTH and -beta E contents were found in the archistriatum and in the lobus parolfactorius.
The archistriatum of the domestic chick has been implicated in both fear behaviour and learning. The efferent connections of discrete anatomical regions of the chick archistriatum were therefore investigated by iontophoresis of the anterograde tracer Phaseolus vulgaris leucoagglutinin into its anterior, dorsal intermediate, ventral intermediate, medial, and posterior parts. The results of this study suggest that the chick archistriatum can be divided into two basic divisions according to whether they project to the following limbic structures: the hippocampal formation, septal areas, lobus parolfactorius, nucleus accumbens, ventral paleostriatum, and dorsomedial thalamus. The limbic archistriatum includes the posterior archistriatum and extends rostrally through the ventral intermediate archistriatum into the anterior archistriatum. The non-limbic archistriatum comprises the dorsal intermediate and medial archistriatum and largely gives rise to specific sensory, somatosensory, and motor telencephalofugal efferents. There may not be distinct borders between these two divisions of the chick archistriatum..
In the current study, in situ hybridization was used to map this change in gene expression to the subregion of lMAN that projects to the robust nucleus of the archistriatum (RA), the principal motor output of the telencephalic circuit that controls song production.
Within a compartment of the robust nucleus of the archistriatum (RA), however, this response dwindled as singing matured.
The intratelencephalic and descending connections of the archistriatum of the mallard were studied using anterograde and retrograde tracers. Autoradiography after injections of [ 3H]-leucine served to visualize the intratelencephalic and extratelencephalic efferent connections of the archistriatum. Four main regions can be recognized in the archistriatum of the mallard: (1) the rostral or anterior part that is a source of contralateral intratelencephalic projections, in particular to the contralateral archistriatum; (2) the dorsal intermediate archistriatum that is the origin of a large descending fiber system, the occipitomesencephalic tract, with projections to dorsal thalamic nuclei, the medial spiriform nucleus, the intercollicular nucleus, the deep tectum, parts of the mesencephalic and bulbar reticular formation, and the subnuclei of the descending trigeminal tract. (3) The ventral intermediate archistriatum is another region that is also a source of intratelencephalic projections, in particular of those to the lobus parolfactorius. (4) The caudoventral intermediate and posterior archistriatum is another region that is a source of the projections to the hypothalamus and thus corresponds to the amygdaloid part of the archistriatum as defined by Zeier and Karten; it also contributes a modest component to the occipitomesencephalic tract. The different cell populations are not spatially separated, which makes it impossible to recognize distinct subnuclei within the four main regions of the archistriatum of the mallard..
It originates in a different part of the archistriatum and projects upon premotor neurons in the medulla that appear to be separate from those projecting upon the syringeal motor nucleus.
HVC neurons which project to the robust nucleus of the archistriatum to form part of the efferent pathway for song production, and HVC interneurons continue to be added throughout life.
This analysis suggests that the major components of the avian dorsal ventricular ridge, i.e., the ventral hyperstriatum, the neostriatum with its various subdivisions, part of the archistriatum, and probably also the piriform cortex, all derive from overlapping portions of the lateral pallial ventricular zone.
The highest levels of IGF-II mRNA expression occurred in three nuclei of the song system: in the high vocal center (HVC), in the medial magnocellular nucleus of the neostriatum (mMAN), which projects to HVC, and to a lesser extent in the robust nucleus of the archistriatum (RA), which receives projections from HVC.
Benzodiazepine binding in the archistriatum was investigated using in vitro quantitative receptor autoradiography. Binding was localised in the anterior, mediale, dorsalis, and ventralis intermedium nuclei of the archistriatum, and there was significantly more binding in the anterior and ventralis intermedium/mediale archistriatum nuclei than in the dorsalis intermedium archistriatum nuclei. Benzodiazepine binding was not altered after handling in any of the investigated nuclei of the archistriatum. The results suggest that whereas several days of gentle handling in chicks leads to a decrease in forebrain GABAA receptors and a decrease in GABA release from the archistriatum, there are no accompanying changes in benzodiazepine receptors.
We found a transient increase in the expression of PKC in the robust nucleus of the archistriatum (RA) during a sensitive period.
In the present experiment, we treated genetic males with estradiol benzoate on embryonic day 5 and measured the volume of and neuron soma size in robust nucleus of the archistriatum (RA) and the high vocal center (HVC), two telencephalic song control nuclei.
Cholinergic fibers innervate the two main song control nuclei of the forebrain: the higher vocal center (HVC) and the robust nucleus of the archistriatum (RA).
CTB and RLF injected in the POM or PVT/nAc/nST were found in cells located in anatomically discrete areas in the telencephalon (hippocampus, septum, archistriatum), hypothalamus (many areas in periventricular position), thalamus, mesencephalon, and pons.
Analysis of retrograde DiI label resulting from DMP injections revealed two major sources of afferent input to DMP originating in regions of the archistriatum and hypothalamus. Inputs to DMP were distributed throughout the dorsal archistriatum and included the area that receives a projection from the parvicellular shell region of the lateral magnocellular nucleus of the anterior neostriatum, a song control nucleus, as well as the dorsal portion of the robust nucleus of the archistriatum, the motor-cortical output of the song control system. The projections from song control regions of the archistriatum to DMP may feed information back into telencephalic song control circuitry via the DMP-->mMAN-->HVC/pHVC pathway.
Copulation induced the appearance of Fos-like immunoreactive (FLI) cells in the preoptic area, the hyperstriatum ventrale, parts of the archistriatum, and the nucleus intercollicularis.
The areas where VIP message was found included the olfactory bulbs, posterior hippocampus, parahippocampal area, hyperstriatum, archistriatum/nucleus (n.) taenia (amygdala), medial part of the LSO, organum vasculosum of the lamina terminalis, medial preoptic region, bed n.
The main vocal motor pathway goes from the high vocal center (HVC) to the robust nucleus of the archistriatum (RA), which in turn innervates mesencephalic and medullary nuclei involved in vocalization.
Photoperiod exerted small but significant steroid-independent effects on the volume of the higher vocal center and the size of neurons in the robust nucleus of the archistriatum.
The seasonal pattern of robust nucleus of the archistriatum volume was similar to that of the HVC.
In the forebrain network for learned vocal behavior in zebra finches, lesions of a cortical region for song control, the lateral magnocellular nucleus of the anterior neostriatum (lMAN), remove presynaptic input to a motor-cortical song region, the robust nucleus of the archistriatum (RA), and cause massive RA neuron death in young birds that are entering the sensitive period for song learning.
The anatomical circuitry underlying memory formation in the chick is likely to involve the intermediate medial hyperstriatum ventrale-archistriatum-LPO arc.
Results from anterograde and retrograde tracing experiments with biocytin and fluorescently labeled dextran amines indicate that the central nucleus of the anterior archistriatum (AAc) is the source of ascending projections upon the oval nuclei of the anterior neostriatum and ventral hyperstriatum (NAo and HVo, respectively).
Possible neural mechanisms or sites that could underly hormonal organization of sexual partner preference in birds and mammals include the anterior hypothalamic/preoptic area, the corticomedial amygdala, and its avian homologue nucleus taeniae of the archistriatum, the septum, and peripheral sensory processes..
(MAN), the high vocal center (HVC) and the robust nucleus of the archistriatum (RA) of males, whereas female song-control nuclei contained many fewer or no labeled cells in these regions.
The posterior dorsal ventricular ridge in reptiles is most likely homologous to the archistriatum in birds and to the pallial amygdala in mammals.
Positive cells were observed also in the neostriatum, including the main auditory area (field L), in several nuclei of the archistriatum and in the hyperstriatum (accessory, dorsal, and ventral).
A lower density of NPY binding sites was found in the different subdivisions of the striatum, the nucleus mesencephalicus lateralis pars dorsalis, the paleostriatum, the archistriatum intermedium pars ventralis, the nucleus geniculatus lateralis, the nucleus taeniae, the locus ceruleus, the nucleus rotondus, the nucleus habenularis medialis, the nucleus dorsomedialis anterior (rostralis) thalami, the pituitary and the area of the hypothalamus with its nuclei such as the nucleus paraventricularis magnocellularis and the nucleus preopticus medialis.
In males, the Nissl-defined volume of the high vocal center, the robust nucleus of the archistriatum, and area X of the lobus parolfactorius increased with age, reaching the adult value at 60, 50, and at 40 days posthatching, respectively. Whereas area X is absent in females, the high vocal center, the robust nucleus of the archistriatum, and the lateral magnocellular nucleus of the anterior neostriatum were detectable throughout development and in adulthood. In contrast to the males, volumes of the high vocal center and of the robust nucleus of the archistriatum decreased in females between 10 and 40 days posthatching (58% and 61%, respectively), when adult values were reached.
Here we show that testosterone accelerates expression of the predominantly oligodendroglia-, but also neuron-associated extracellular matrix glycoprotein tenascin-R and the oligomannosidic carbohydrate L3 during the third and seventh posthatching week in the higher vocal center (HVC) and robust nucleus of the archistriatum (RA), but not in other brain regions.
Here we show that the ability of barn owls to orient their gaze towards and fly to the remembered location of auditory targets is lost during pharmacological inactivation of a small region in the forebrain, the anterior archistriatum. The data demonstrate that in the avian archistriatum, as in the mammalian frontal cortex, there exists a region that is essential for the expression of spatial working memory and that, in the barn owl, this region encodes auditory spatial memory..
Two afferents to the robust nucleus of the archistriatum (RA) are important for song learning by the zebra finch.
NCL receives telencephalic projections from the hyperstriatum accessorium, cells along the border of hyperstriatum dorsale and hyperstriatum ventrale, anterolateral hyperstriatum adjacent to the vallecula, confined cell groups within the anterior neostriatum, and subdivisions of the archistriatum.
In the robust nucleus of the archistriatum (RA), this sex difference in neuron number arises because neuron survival is greater in young males than in females. No such sexual dimorphism in the density of 3[ H]thymidine labeled cells was evident in the archistriatum lateral to the RA, or within the RA of adult birds.
In contrast, the robust nucleus of the archistriatum (RA) and the supralaminar area of the frontal neostriatum in budgerigars, like the RA and the magnicellular nucleus of the neostriatum (MAN) in songbirds, respectively, contained few or no ChAT labeled somata, fibers, and varicosities and stained lightly for AChE.
Dorsolateral injections gave rise to projections innervating the rostralmost extension of the HP, a laminar complex including the dorsal and ventral hyperstriata and the lamina frontalis superior, the rostral lobus parolfactorius, the medial and ventral paleostriatal regions, the lateral septal nucleus, the nucleus of the diagonal band, the dorsolateral corticoid area, the archistriatum posterius, and the nucleus taeniae in the telencephalon.
In addition, clHV and parts of the field L complex project strongly to the "shelf" of neostriatum underneath the song control nucleus high vocal center (HVC) and to the "cup" of archistriatum rostrodorsal to another song-control nucleus, the robust nucleus of the archistriatum (RA).
Serotonin-IR fibers and terminals were found to be very broadly distributed within the brain and were particularly prominent in several structures of the telencephalon (archistriatum pars dorsalis, nucleus taeniae, area parahippocampalis, septum), diencephalon (nuclei preopticus medianus, magnocellularis, nucleus geniculatus lateralis pars ventralis, nucleus triangularis, nucleus pretectalis), mesencephalon-rhombencephalon (superficial layers of the optic tectum, nucleus ectomamillaris, nucleus isthmo-opticus and in most of the cranial nerve nuclei).
The efferent projections of each of the three major parts of NB were mainly to the adjacent neostriatum frontale (NF), which then provided projections to the lobus parolfactorius (exclusive of area X), the lateral archistriatum intermedium (Ail), and the lateral neostriatum caudale (NCl).
Small neurons in a sexually dimorphic nucleus of the zebra finch, the robust nucleus of the archistriatum (RA), were immunoreactive for gamma-aminobutyric acid (GABA).
In a previous study, electrical microstimulation of the AGF was shown to produce saccadic movements of the eyes and head, and anatomical data revealed that neurons in the AGF region of the archistriatum project directly to brainstem tegmental nuclei that mediate gaze changes.
The chick archistriatum has been implicated in avoidance learning and filial imprinting. However, its role in these learning paradigms may be due to the inhibition of normal avoidance responses, since the avian archistriatum has been shown to play a role in fear/avoidance behaviour. The involvement of the archistriatum in the expression of unlearned fear/avoidance behaviour was therefore investigated in two day-old chicks. These results demonstrate that in the young chick, the archistriatum may be involved in the response to mild or intermediate levels of environment or isolation-related stress, but does not appear to be important for overt fear responses or avoidance of novel objects. Taken together with the results of previous work, the data suggests that the archistriatum may be directly involved in avoidance learning and imprinting..
In this study we assessed sex differences in the volume of two vocal control nuclei, the high vocal center (HVC) and the robust nucleus of the archistriatum (RA) in zebra finches (Taeniopygia guttata) exposed to various endocrine treatments (neonatal treatment with an aromatase inhibitor and/or an adult treatment with testosterone). Immunoreactive fibers for vasoactive intestinal polypeptide and enkephalin also allowed one to define the boundary of the robust nucleus of the archistriatum but they did not fill the entire area of the nucleus as is the case for the high vocal center.
Although both ligands bound throughout the brain, most telencephalic regions, including the archistriatum, the neostriatum, and basal ganglia structures like lobus paraolfactorius, nucleus accumbens, and paleostriatum, showed a higher density of M1-like sites.
The effects of acetylcholine (ACh) on synaptoneurosomes of the robust nucleus of the archistriatum (RA), one of the song control nuclei, were investigated during the sensitive period of song learning in the zebra finch.
All three subdivisions project to area X and the robust nucleus of the archistriatum, with more complexity in the classes and distribution of cells than previously reported.
High aromatase mRNA expression was observed in the caudal neostriatum, limbic archistriatum, and hypothalamus.
When a deposit of the anterograde tracer was centered in HA, efferent fibers were seen to extend mainly in three directions: 1) medially to the tractus septomesencephalicus, which sends projections to extratelencephalic visual nuclei: 2) ventrolaterally to the lateral portion of the neostriatum frontale, where there were also labeled cells after the retrograde tracer was injected in HA; and 3) ventromedially to the paleostriatal complex, which is the avian equivalent of the mammalian caudale, 5) neostriatum intermedium, 6) archistriatum intermedium, and 7) hyperstriatum laterale.
At 105 to 110 days of age, we measured the volumes of Area X, higher vocal center (HVC), robust nucleus of the archistriatum (RA), soma sizes in HVC, RA, and the lateral magnocellular nucleus of the neostriatum (IMAN), and neuron density and number in RA.
A serial pathway from a thalamic nucleus (DLM; the medial portion of the dorsolateral nucleus of the anterior thalamus) to a cortical region (lMAN; the lateral magnocellular nucleus of the anterior neostriatum) to a motor-cortical region (RA; the robust nucleus of the archistriatum) is necessary for vocal production during song learning in juvenile zebra finches but not for the recitation of a song already learned by adults. In turn, lMANshell neurons project solely to an arc-shaped region of dorsal archistriatum just lateral to RA (Ad; archistriatum, pars dorsalis), whereas lMANcore neurons project exclusively to RA. We also identified crossed and reciprocal pathways between lMANcore/shell and the lateral portion of the ventral archistriatum, which may contribute to interhemispheric coordination of vocal behavior.
Among the limbic structures, the neostriatum caudolaterale (a possible equivalent of the mammalian prefrontal cortex), the septum, the nucleus accumbens, and parts of the archistriatum were heavily labelled by DA-like axons.
We identified a region in the archistriatum of the barn owl forebrain that contains neurons sensitive to auditory stimuli. The archistriatum is known to be the primary source of motor-related output from the avian forebrain and, in barn owls, contributes to the control of gaze, much like the frontal eye fields in monkeys. The auditory region is located in the medial portion of the archistriatum, at the level of the anterior commissure, and is within the region of the archistriatum from which head saccades can be elicited by electrical microstimulation (see preceding companion article, Knudsen et al., 1995). The auditory properties of units in the medial archistriatum are similar to those of units in the optic tectum, a structure that also contributes to gaze control. Unlike the optic tectum, however, the auditory region of the archistriatum does not contain a single, continuous auditory map of space. The different representations of auditory space in closely related structures in the forebrain (archistriatum) and midbrain (optic tectum) probably reflect the fact that the forebrain contributes to a wide variety of sensorimotor tasks more complicated than gaze control..
We present evidence that the archistriatum in the forebrain of the barn owl participates in gaze control, that it can mediate gaze changes independently of the optic tectum (OT), and that it projects in parallel to both the OT and to saccade-generating circuitry in the brainstem tegmentum. Head (and eye) saccades were elicited from the anterior 70% of the archistriatum, a region that we refer to as the archistriatal gaze fields (AGF). Using anatomical pathway tracing techniques, we found that the archistriatum projects strongly and in parallel to the deep layers of the OT and to nuclei in the midline brainstem tegmentum. The direct anatomical pathway from the archistriatum to the midline tegmental nuclei can account for saccades that persist following OT inactivation.
However, we did not find PSA-N-CAM associated with young migrating cells in the high vocal center (HVC), nor was there PSA-N-CAM in the robust nucleus of the archistriatum (RA), which is known to receive new axonal endings from HVC.
It has been shown that the anterior forebrain pathway sequentially connects the following nuclei: the high vocal center, area X of lobus parolfactorius, the medial portion of the dorsolateral thalamic nucleus, the lateral magnocellular nucleus of anterior neostriatum (IMAN), and the robust nucleus of the archistriatum (RA).
Clusters of immunoreactive cell bodies were also detected in the hyperstriatum accessorium (HA), the ventral portions of both the archistriatum and the corticoid area, the preoptic area (POA), the anterior hypothalamus (AHy) and the dorsolateral thalamus (DL).
PKC gamma-stained cells were distributed widely in the telencephalon, including all hyperstriatal structures (including the IMHV), the hippocampus, neostriatum, ectostriatum and archistriatum. The distribution of PKC alpha beta-stained cells was more limited, with staining in the archistriatum, hippocampus and septum but not in the hyperstriatum. There was some PKC alpha beta-staining of putative neurones in the hippocampus, septum and archistriatum.
This expanse includes the Wulst and archistriatum as well as the entire outer rind of the pallium intervening between Wulst and archistriatum, termed by us the pallium externum (PE). A restricted number of these pallial regions (such as the "limbic" NCL, pyriform cortex, and ventral/caudal parts of the archistriatum) project to such ventral striatal structures as the olfactory tubercle (TO), nucleus accumbens (Ac), and bed nucleus of the stria terminalis (BNST). Such "limbic" pallial areas also project to medialmost LPO and lateralmost PA, while the hyperstriatum accessorium portion of the Wulst, the PE, and the dorsal parts of the archistriatum were found to project primarily to the remainder of LPO (the lateral two-thirds) and PA (the medial four-fifths). The extensive corticostriatal system in both birds and mammals appears to include two types of pallial neurons: 1) those that project to both striatum and brainstem (i.e., those in the Wulst and the archistriatum) and 2) those that project to striatum but not to brainstem (i.e., those in the PE).
To analyse the influences of estradiol on the differentiation of neurons in the song motor centers RA (robust nucleus of the archistriatum) and HVc (higher vocal center), juvenile male zebra finches were treated with the aromatase inhibitor, Fadrozole (CGS 16949A).
Concentrations of cAR mRNA are detectable in several of the song control nuclei of the forebrain, including high vocal center (HVC), lateral magnocellular nucleus of the anterior neostriatum and robust nucleus of the archistriatum.
We measured volumes of area X, the higher vocal center (HVC), and the robust nucleus of the archistriatum (RA); measured soma sizes in the lateral magnocellular nucleus of the neostriatum (lMAN), HVC, and RA; and counted RA neurons.
The telencephalic song-control nuclei MAN (magnocellular nucleus of the anterior neostriatum), Area X of the striatum, HVC (higher vocal center), and RA (robust nucleus of the archistriatum) contained abundant ENK immunoreactivity, including labeled fibers and somata.
T-induced growth of HVC occurred regardless of whether the borders of HVC were defined by Nissl-staining, the distribution of androgen-concentrating cells, or the distribution of projection neurons [ separate neuronal populations within HVC project to the robust nucleus of the archistriatum (RA) and to Area X of the avian striatum (X)].
In contrast, ZENK induction is much lower or absent in the archistriatum, the primary telencephalic sensory-recipient areas (including auditory field L), and the three telencephalic androgen receptor-containing song nuclei (high vocal center, lateral magnocellular nucleus of the anterior neostriatum, and the robust nucleus of the archistriatum).
A brain nucleus that is important for the generation of song in the adult male zebra finch (Poephila guttata), the robust nucleus of the archistriatum (RA), receives dual inputs from two other telencephalic song nuclei: the hyperstriatum ventrale pars caudale (HVc) and the lateral magnocellular nucleus of the anterior neostriatum (L-MAN).
Specific labeling densities were associated with avian equivalents of the mammalian pyramidal system (hyperstriatum accessorium; archistriatum intermedium and tractus occipitomesencephalicus) and extrapyramidal system (paleostriatum augmentatum, paleostriatum primitivum and lobus parolfactorius), as well as several limbic structures (hippocampal formation, nucleus taeniae and the caudal part of the archistriatum).
Retrograde labelling from LPO was found in the archistriatum, dorsomedial thalamic complex, nuclei lateralis anterior and superficialis parvicellularis thalami, substantia nigra, central gray, area ventralis tegmentalis of Tsai, and locus coeruleus and in cells dorsal to the decussation of brachium conjunctivum.
The chick archistriatum receives afferents from the intermediate part of the medial hyperstriatum ventrale (IMHV) and projects to the lobus parolfactorius (LPO). The aim of the current study was to characterize the termination pattern of medial hyperstriatal afferents within the archistriatum to determine whether the archistriatum may act as a relay between the IMHV and LPO. Following iontophoresis of Phaseolus vulgaris leucoagglutinin into the medial hyperstriatum ventrale (including the IMHV) of 1-week-old domestic chicks, anterogradely labelled fibers were observed to descend through the medial neostriatum and paleostriatum to enter the archistriatum. These medial hyperstriatum ventrale afferents arborised profusely to give varicose axon branches within all except the anterior part of the archistriatum. However, the greatest density was present in the ventral part of the intermediate archistriatum. Medial hyperstriatum ventrale afferents were not observed to contact calbindin immunoreactive, presumptive "local circuit" neurons, within the archistriatum, despite a spatial overlap in their distribution. These results suggest that the archistriatum may be capable of mediating the transfer of information from the IMHV to the LPO..
(4) CB-HRP traces revealed that HVc projected to robust nucleus of the archistriatum, and atea X of lobus parolfactorius.
Other areas of prominent binding were the superficial layers of optic tectum, one of the isthmic nuclei, the hippocampus, the hyperstriatum accessorium and the archistriatum ventrale.
In particular, archistriatum, anterior neostriatum, and the hippocampus had most of their neurons labeled before hatching.
However, the number of 3H-labeled HVC neurons that projected to robust nucleus of the archistriatum (RA) in the long-survival birds was three times greater in the hormone-treated than in the control group, though the total number of RA-projecting cells did not change significantly.
This was true for HVC neurons projecting to the robust nucleus of the archistriatum and for other HVC neurons that could not be retrogradely filled from the robust nucleus of the archistriatum.
Neuronal damage, determined qualitatively using a silver impregnation method, was observed in several forebrain regions including the hippocampus, hyperstriatal regions, paleostriatum primitivum, ventral archistriatum, and lateral corticoid area.
The dorsal zone of Nf projects to the sensorimotor part of archistriatum, to the paleostriatum augmentatum (PA) and to the lateral lobus parolfactorius. Here, too, Ni has projections to archistriatum and probably to PA. archistriatum is the source of a large descending pathway with, among others, substantial projections to the parvocellular reticular formation of the brain stem.
GABA-LIR was found throughout the song system in neurons and neuropil of the robust nucleus of the archistriatum (RA), the higher vocal center (HVC), Area X, the magnocellular nucleus of the neostriatum (MAN), and the dorsomedial portion of the nucleus intercollicularis (DM of ICo).
The avian archistriatum has been demonstrated to play a role in agonistic behaviours and avoidance learning. The involvement of the archistriatum in the learning process of filial imprinting was therefore investigated in day-old chicks. These results demonstrate that the archistriatum is essential for the expression of an imprinted preference. Taken together with the results of previous work, the current data suggest that the archistriatum may be involved in retention of significant aspects of the imprinting experience, or in motivation to approach imprinting objects..
The avian archistriatum, part of which may be homologous with the mammalian amygdala, has been implicated in fear and avoidance behaviour. In view of the possible involvement of the archistriatum in avoidance and learning behaviour, its role in one-trial PAL was investigated by ablation. Bilateral electrolytic lesions of the entire archistriatum prevented the acquisition of the one-trial PAL task. The archistriatum could therefore be directly involved in memory formation.
In addition, we found that although many thymidine-labeled HVC neurons ultimately project to the robust nucleus of the archistriatum (RA), a sexually dimorphic target, sex differences in their number develop before this efferent projection is established.
Nuclear components of the limbic system (archistriatum, amygdala and habenular complex) did not reveal specific labelling by the radioligand at E20 with constant, moderate binding densities evaluated for E27, P3 and P14.
Injections on posthatching days 1-30 had no effect on the volumes of the robust nucleus of the archistriatum (RA) and area X or on neuron soma size in RA and high vocal center (HVC) measured on day 31.
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