At the same time, attention decreases neuronal responses in the adjacent thalamic reticular nucleus (TRN). 
Compared to control, vAChT was lowered (up to 50%) at each time point after trauma, with reductions in olfactory tubercle, basal forebrain, motor cortex, putamen, thalamic and hypothalamic areas and the gigantocellular reticular nucleus. Time-dependent reductions of about 20% of nAChR-density in the thalamus, hypothalamus, olfactory tubercle, gigantocellular reticular nucleus and motor cortex were observed post-TBI at 24 and 72 h.
Here we investigate the correlation between the expression of T-channel coding genes (alpha1G, -H, -I), T-type Ca(2+) current, and the T-current-dependent low threshold Ca(2+) spike in three functionally distinct thalamic nuclei (lateral geniculate nucleus; centrolateral nucleus; reticular nucleus) in a rat model of absence epilepsy, the WAG/Rij rats, and a non-epileptic control strain, the ACI rats.
The reticular nucleus, zona incerta, and lateral habenular nucleus held numerous DAT-ir axons in both species.
Transmission through the thalamus activates circuits involving the GABAergic neurons of the thalamic reticular nucleus (TRN).
thalamic reticular nucleus (TRN) neurons and dLGN interneurons).
Following tracer injections into the thalamus, retrogradely labelled neurons were found in the depth of the olfactory tubercle (particularly the hilus of the Callejal islands and the insula magna), in subdivisions of the diagonal band complex, the peripeduncular region and the thalamic reticular nucleus. The only regions projecting to the lateral thalamus appeared to be the thalamic reticular nucleus (RTh) and the dorsal peripeduncular nucleus (PpD).
Within the thalamocortical circuitry, Kv3.1 and Kv3.3 subunits are highly expressed in the thalamic reticular nucleus (TRN), which is thought to act as a pacemaker at sleep onset and to be involved in slow oscillatory activity (spindle waves) during slow-wave sleep.
In particular, GABA A receptors containing the alpha3 subunit are expressed predominantly in cortical layer VI and thalamic reticular nucleus (nRT) and regulate the activity and firing pattern of neurons in relay nuclei.
We compared intracellular responses of MGB neurons to electrical stimulation of the AC following bilateral ablation of the inferior colliculi (IC) or thalamic reticular nucleus (TRN) in anesthetized guinea pigs.
The ventral part of the oral pontine reticular nucleus (vRPO) is a demonstrated site of brainstem REM-sleep generation and maintenance.
Interposed between the thalamus and cortex, the inhibitory thalamic reticular nucleus intercepts and regulates communication between the two structures. Recent findings demonstrate that a unique circuitry links the prefrontal cortex with the reticular nucleus and may underlie the process of selective attention to enhance salient stimuli and suppress irrelevant stimuli in behavior. Unlike other cortices, some prefrontal areas issue widespread projections to the reticular nucleus, extending beyond the frontal sector to the sensory sectors of the nucleus, and may influence the flow of sensory information from the thalamus to the cortex. Unlike other thalamic nuclei, the mediodorsal nucleus, which is the principal thalamic nucleus for the prefrontal cortex, has similarly widespread connections with the reticular nucleus. Unlike sensory association cortices, some terminations from prefrontal areas to the reticular nucleus are large, suggesting efficient transfer of information. We propose a model showing that the specialized features of prefrontal pathways in the reticular nucleus may allow selection of relevant information and override distractors, in processes that are deranged in schizophrenia..
In addition to its expression in glia, mGlu3 was distinctively expressed in cells in the GABAergic reticular nucleus of the thalamus. Local infusion of a non-selective mGlu2/3 agonist, LY379268, in the reticular nucleus of the thalamus, significantly reduced GABA release, suggesting that mGlu3 may also play a role in central disinhibition..
Most dorsal thalamic nuclei send axons to specific areas of the neocortex and to specific sectors of the thalamic reticular nucleus; the neocortex then sends reciprocal connections back to the same thalamic nucleus, directly as well indirectly through a relay in the thalamic reticular nucleus. The present study shows that cells of the hippocampal formation as well as cells in the reuniens nucleus are retrogradely labelled following injections of horseradish peroxidase or fluoro-gold into the rostral part of the thalamic reticular nucleus in the rat. Labelled neurons were seen in the hippocampal formation and nucleus reuniens only after injections made in the rostral thalamic reticular nucleus (1.6-1.8 mm caudal to bregma). In addition, the present study confirmed the presence of afferent connections to the rostral thalamic reticular nucleus from cortical (cingulate, orbital and infralimbic, retrosplenial and frontal), midline thalamic (paraventricular, anteromedial, centromedial and mediodorsal thalamic nuclei) and brainstem structures (substantia nigra pars reticularis, ventral tegmental area, periaqueductal grey, superior vestibular and pontine reticular nuclei). These results demonstrate a potential for the thalamo-hippocampal circuitry to influence the functional roles of the thalamic reticular nucleus, and show that thalamo-hippocampal connections resemble the circuitry that links the sensory thalamus and neocortex..
GABAergic cells of the thalamic reticular nucleus (TRN) can potentially exert strong control over transmission of information through thalamus to the cerebral cortex.
The thalamic reticular nucleus (TRN) supplies an important inhibitory input to the dorsal thalamus.
posterodorsal area (PD) and ventral auditory area (VA), in the rat cortex have similar topographies in the projection to the ventral division of the medial geniculate nucleus (MGV), but reverse topographies in the projection to the thalamic reticular nucleus (TRN).
Most theories, proposed to describe this response modulation have postulated that the thalamic reticular nucleus (TRN) plays a role in this response modulation. To test this idea, we used multineuron recordings and demonstrate, for the first time, that the responses of single neurons in the reticular nucleus are modulated by the behavior of the animal.
MLR excitatory inputs to reticulospinal cells in the middle (MRRN) are larger than those in the posterior rhombencephalic reticular nucleus (PRRN).
The thalamic reticular nucleus is a layer of GABAergic neurons that occupy a strategic position between the thalamus and cortex. In contrast, those to the posterior nucleus were complicated and varied considerably among neurons: although almost all contained a single elliptical region near the reticulothalamic border, in most cases, they consisted of additional discontinuous regions or relatively diffuse regions throughout the thickness of the thalamic reticular nucleus. Our results suggest two sources of reticular inputs to the posterior nucleus neurons: one that is relatively topographic from regions near the reticulothalamic border and one that is relatively diffuse and convergent from most or all of the thickness of the thalamic reticular nucleus.
In contrast, both GABA(B(1a,2)) and GABA(B(1b,2)) receptors efficiently inhibit the release of GABA from thalamic reticular nucleus (TRN) neurons onto TCR neurons.
Neuronal responses to auditory stimuli and electrical stimulation were examined in 104 neurones in the auditory sector of thalamic reticular nucleus (TRN) and nine medial geniculate (MGB) neurones from anaesthetized guinea pigs.
The simplicity of the model was motivated by two questions: (1) Can an LGN model that is driven by a retinal spike train recorded as synaptic ('S') potentials, but does not include a diverse array of ion channels, nor feedback inputs from the cortex, brainstem, and thalamic reticular nucleus, accurately simulate the LGN discharge on a spike-for-spike basis? (2) Are any special synaptic mechanisms, beyond simple summation of currents, necessary to model experimental recordings? We recorded cat relay cell responses to spatially homogeneous small or large spots, with luminance that was rapidly modulated in a pseudo-random fashion.
Given the current knowledge of the neurophysiology of absence seizures, this specificity of the frontal cortical discharges suggests the hypothesis that absence spells are associated with pathology in a circuit comprising ventromedial frontal cortex, rostral thalamic reticular nucleus, and limbic nuclei of the thalamus.
The lateral reticular nucleus (LRN) resides in the rostral medulla and caudal pons, is implicated in cardiovascular regulation and cranial nerve reflexes, and gives rise to mossy fibers in the cerebellum.
In the thalamus, two distinct types of IPSC kinetics are observed: thalamocortical relay neurons in the ventrobasal nucleus (VB) exhibit a fast decaying IPSC, whereas neurons in the adjacent reticular nucleus (RTN) display a long-lasting, slowly decaying IPSC.
The contribution of neurotransmitters and related receptors, the involvement of thalamic reticular nucleus (TRN), and the role of neuronal firing patterns in this process were also examined.
The degree of synchrony within the thalamic network seems to be crucial in determining whether normal (spindle) or pathological (spike-wave) oscillations occur, and recent studies show that regulation of excitability in the reticular nucleus leads to dynamical modulation of the state of the thalamic circuit and provide a basis for explaining how a variety of unrelated genetic alterations might lead to the spike-wave phenotype. In addition, given the central role of the reticular nucleus in generating spike-wave discharge, these studies have suggested specific interventions that would prevent seizures while still allowing normal spindle generation to occur.
The earliest thalamic neurons generated between embryonic days (E) 13 and 15 include those of the reticular nucleus, entirely composed by GABAergic neurons. In the perinatal period, the preponderance of GABAergic neurons was restricted to the reticular nucleus and several GABAergic fibers were still detectable throughout the thalamus.
The thalamic reticular nucleus (TRN) provides inhibitory innervation to most thalamic relay nuclei and receives excitatory innervation from both cortical and thalamic neurons.
For both nuclei, some of the feedback responses were purely disynaptic inhibitory postsynaptic potentials (IPSPs) from the thalamic reticular nucleus (TRN).
Considering the lack of interneurons in rodent VB, the NO-mediated actions likely involve an increase in the output of axon terminals of thalamic reticular nucleus neurons.
CONCLUSIONS: Sleep spindles are generated by the thalamic reticular nucleus in conjunction with specific thalamic nuclei and are modulated by corticothalamic and thalamocortical connections.
PSA-NCAM labelling remained intense and homogeneously distributed along perinatal period, but from P4 it began to decrease selectively, persisting throughout adulthood only in the reticular nucleus, ventral lateral geniculate nucleus and midline and intralaminar nuclei.
The thalamic reticular nucleus (nRt) provides a major source of inhibition in the thalamo-cortical circuit and is critically involved in the generation of spindle oscillations.
The thalamic reticular nucleus (TRN) can been subdivided into sectors based on thalamic and cortical input.
Thalamic interneurons and thalamic reticular nucleus (TRN) neurons provide inhibitory innervation of thalamocortical cells that significantly influence thalamic gating.
Similarly, GABA(B2) mRNA was not found in the reticular nucleus.
This review analyzes current concepts of the structural organization and ultrastructure of the reticular nucleus of the thalamus (RNT) and the neurochemical characteristics of its neurons.
Immunohistochemical methods were used to label singly and/or in combination glutamic acid decarboxylase (GAD, the sole synthesizing enzyme for the inhibitory neurotransmitter gamma-aminobutyric acid) and phosphate-activated glutaminase (GLN, a synthesizing enzyme for glutamate) in neurons of lateral reticular nucleus (LRN) of thalamus of adult cats.
The aim of the present study was to investigate the effect of local injections of the GABA(A) receptor antagonist, bicuculline, into the rostral and caudal parts of the thalamic reticular nucleus (TRN), on the generation of spike-and-wave discharges in Genetic Absence Epilepsy Rats from Strasbourg (GAERS).
GABAergic neurons of the thalamic reticular nucleus (nRt) provide thalamocortical relay neurons with feedback inhibition that influences sensory processing and thalamocortical rhythm generation.
These axons were especially well-preserved after traversing the reticular nucleus, the location chosen for stimulation of thalamostriatal afferents.
GABA signaling within the reticular nucleus (Rt) and the ventrobasal complex (VB) of the thalamus is critical to the neurophysiology of absence seizures.
This study demonstrated that there is a pathway from the zona incerta to the thalamic reticular nucleus. Injections of horseradish peroxidase or Fluorogold were made, using stereotaxic coordinates, into the rostral, intermediate or caudal regions of the thalamic reticular nucleus of adult Sprague-Dawley rats. The results show that the different regions of the thalamic reticular nucleus have distinct patterns of connections with the sectors of the zona incerta. In terms of the relative strength of the connections, injections made into the rostral regions of the thalamic reticular nucleus showed the highest number of labelled cells within the rostral and ventral sectors of the zona incerta; injections made into the intermediate regions of the thalamic reticular nucleus showed labelled cells in the dorsal and ventral sectors; while injections to the caudal regions of the thalamic reticular nucleus showed only a few labelled cells in the caudal sector of the zona incerta.
The thalamic reticular nucleus is strategically located in the axonal pathways between thalamus and cortex, and reticular cells exert strong, topographic inhibition on thalamic relay cells.
The inhibitory thalamic reticular nucleus (TRN) intercepts and modulates all corticothalamic and thalamocortical communications.
In addition, orexin-A produced a small depolarization in 28% of neurons in the thalamic reticular nucleus (TRN).
The thalamic reticular nucleus (TRN) is a sheet of GABAergic neurons that project to other TRN neurons and to associated thalamocortical relay nuclei.
The neuronal composition of the thalamic reticular nucleus was studied in serial sections of the sagittal and frontal projections impregnated with silver nitrate by the Golgi method. The neuronal composition of the reticular nucleus of the human thalamus was wider than has previously been described in animals and humans. The principles of the organization of the reticular nucleus of the human thalamus are described..
Acting on this vital relay is another thalamic nucleus, the thalamic reticular nucleus (TRN).
We searched the anatomical origin of the cholinergic projection to the GN throughout the hindbrain and forebrain, and we found that the cholinergic fibers originated mainly in the pontine reticular nucleus (PRN).
In the last 15 years a role has been ascribed for the medullary dorsal reticular nucleus as a supraspinal pain modulating area. The medullary dorsal reticular nucleus is reciprocally connected with the spinal dorsal horn, is populated mainly by nociceptive neurons and regulates spinal nociceptive processing. Here we analyze the distribution of brain projections from the medullary dorsal reticular nucleus using the iontophoretic administration of the anterograde tracer biotinylated-dextran amine and the retrograde tracer cholera toxin subunit B. Fibers and terminal boutons labeled from the medullary dorsal reticular nucleus were located predominately in the brainstem, although extending also to the forebrain. The well-known role of the medullary dorsal reticular nucleus in nociception and its pattern of brain projections in rats suggests that the nucleus is possibly implicated in the modulation of: (i) the ascending nociceptive transmission involved in the motivational-affective dimension of pain; (ii) the endogenous supraspinal pain control system centered in the periaqueductal gray matter-rostral ventromedial medulla-spinal cord circuitry; (iii) the motor reactions associated with pain..
However, in the reticular nucleus, which lacks alpha1-GABA(A) receptors in wild-type mice, postsynaptic alpha3/gamma2/gephyrin clusters were unaffected.
Synchrony within the thalamocortical system is regulated in part by intranuclear synaptic inhibition within the reticular nucleus (RTN).
Among the regions displaying the most intense labelling were the olfactory tubercle, lateral septum (LS), caudate putamen (Cpu), central amygdaloid nucleus (Ce), paraventricular hypothalamic nucleus (PVN), supraoptic nucleus (SO), lateral hypothalamic area (LHA), ventromedial hypothalamic nucleus (VMH), lateral reticular nucleus (LRt) and solitary tract nucleus (NTS).
These two compounds, when injected via cannulae into the reticular nucleus of the thalamus (NRT), decreased significantly the duration of seizures as compared with saline injections or injections of the CBX inactive derivative glycyrrhizic acid.
In contrast, dopamine did not alter inhibitory synaptic transmission arising from either dLGN interneurons or thalamic reticular nucleus neurons.
The beta3-subunit deficiency causes a failure of intrathalamic reticular nucleus inhibition, leading to abnormally synchronized thalamocortical oscillations.
Spindles are generally regarded as being generated by intrathalamic circuitry, as decorticated thalamic slices and the isolated thalamic reticular nucleus exhibit spindles.
The corticothalamic feedback pathway provides excitatory synaptic input to both the thalamic reticular nucleus and the lateral geniculate nucleus. We studied excitatory postsynaptic currents elicited from corticothalamic stimulation in the visual sector of the thalamic reticular nucleus and the lateral geniculate nucleus to compare the response of these neurons to stimulation of their common input pathway. We found that single thalamic reticular nucleus excitatory postsynaptic currents were significantly sharper than lateral geniculate nucleus responses. The mean thalamic reticular nucleus excitatory postsynaptic current decay constant (tau) was 4.9+/-0.5 ms, while the mean lateral geniculate nucleus excitatory postsynaptic current tau value was 11.8+/-0.8 ms. Presynaptic release dynamics as measured by responses to paired stimuli were conserved between the thalamic reticular nucleus and lateral geniculate nucleus. Lateral geniculate nucleus responses showed proportionately larger facilitation (reaching 842.9 +/- 76.4% of excitatory postsynaptic current 1 amplitude) than thalamic reticular nucleus responses (reaching 223.1 +/- 44.0% of excitatory postsynaptic current 1 amplitude). These data indicate that while the corticothalamic pathway produces excitatory postsynaptic currents in both the thalamic reticular nucleus and lateral geniculate nucleus, other factors uniquely affect the functional integration of the inputs in each nucleus..
We found that the activation of metabotropic glutamate receptors, via endogenous neurotransmitter or by agonist, causes long-term reduction of electrical synapse strength between the inhibitory neurons of the rat thalamic reticular nucleus..
In the mesencephalon, immunoreactive perikarya were seen in the mesencephalic reticular formation, reticular nucleus of the isthmus and torus semicircularis.
Both controls and pilocarpine-treated animals presented neo-Timm staining in the anterodorsal nucleus, laterodorsal nucleus, reticular nucleus, most intralaminar nuclei, nucleus reuniens, and rhomboid nucleus of the thalamus, as well as in the zona incerta.
Within the thalamus, electrical coupling is observed in the reticular nucleus, which is composed entirely of GABAergic neurons.
In the diencephalon, the medial habenula was most reactive followed by the reticular nucleus of the thalamus.
A possible function is that they may exert distinct corticofugal modulations on thalamic information processing through their parallel connections with the medial geniculate body and thalamic reticular nucleus. In contrast to the similar topography in the projections to the ventral division of the medial geniculate body, collateral projections to the thalamic reticular nucleus terminated in the opposite dorsal and ventral zones of the lateral and middle tiers of the nucleus in each pair of the tonotopically comparable cortical subfields. In addition, the projections of the non-primary cortical subfields further arborized in the medial tier of the thalamic reticular nucleus. On the other hand, corticofugal inhibition via the thalamic reticular nucleus may operate in different parts of the ventral division of the medial geniculate body or different thalamic nuclei.
We used laser scanning photostimulation through a focused UV laser of caged glutamate in an in vitro slice preparation through the rat's somatosensory thalamus to study topography and connectivity between the thalamic reticular nucleus and ventral posterior lateral nucleus. We were thus able to confirm and extend previous observations based mainly on neuroanatomical pathway tracing techniques: the projections from the thalamic reticular nucleus to the ventral posterior lateral nucleus have precise topography. The reticular zone, which we refer to as a "footprint," within which photostimulation evoked inhibitory postsynaptic currents (IPSCs) in relay cells, was relatively small and oval, with the long axis being parallel to the border between the thalamic reticular nucleus and ventral posterior lateral nucleus.
Tracer application into the cervical spinal cord, combined with CB immunohistochemistry, resulted in retrogradely labeled cells throughout the brain, five groups of which showed CB immunoreactivity: (1) the mesencephalic trigeminal nucleus, (2) the laterodorsal tegmental nucleus, (3) the raphe nucleus, (4) the middle reticular nucleus and (5) the inferior reticular nucleus.
Based on morphological and neurochemical similarity of the turtle Enta, caiman Pedd nucleus, the superior reticular nucleus in birds, and the thalamic reticular nucleus in mammals, we suggest that these structures represent a characteristic component which is common to the thalamic organization in amniotes..
Electrical stimulation of the reticular nucleus of the rat thalamus results in activation of c-fos immunoreactivity in nerve cells of the ipsilateral retrosplenial cortex. Conversely, electrical stimulation of the retrosplenial cortex induced c-fos immunoreactivity in the ipsilateral reticular nucleus of the thalamus.
These include the relatively small size of the thalamic reticular nucleus and the preponderance of calbindin immunoreactive neurons over parvalbumin immunoreactive neurons in the ventral posterior nucleus..
Asymmetrical increases in the number of Fos-IR cells were also observed in the subcortical region that receives the main cortical projection from the somatosensory cortex, the somatic region of the reticular nucleus of the thalamus (reticular thalamus).
OBJECTIVES: To validate a method for the chronic implantation of micro-cannulae to examine the effect of drug administration to two small brain regions critical to the control of generalised seizures, the reticular nucleus of the thalamus (Rt) and the ventrobasal thalamus (VB), in a genetically epileptic rat model.
Motor reafference is postulated to be mediated via pallidal projections to the thalamic reticular nucleus, which is known to modulate thalamocortical pathways.
The EEG abnormalities in ADHD were accounted for by the model's neurophysiological parameters as follows: (i) dendritic response times were increased, (ii) intrathalamic activity involving the thalamic reticular nucleus (TRN) was increased, consistent with enhanced delta-theta activity, and (iii) intracortical activity was increased, consistent with slow wave (<1 Hz) abnormalities.
Consistent with a global role of DJ-1 in the brain, we found immunoreactivity, for example, in cortical areas, hippocampus, basolateral amygdala, the reticular nucleus of the thalamus, zona incerta, and locus coeruleus.
The proposed pathways for a component motor efference copy from both the cerebellum and basal ganglia converge on the thalamus and modulate thalamocortical projections via the thalamic reticular nucleus.
GABAergic projection from thalamic reticular nucleus to thalamic nucleus submedius in the medial thalamus of the rat was studied by using immunohistochemistry for GABA, retrograde labeling with Fluoro-Gold combined with immunohistochemistry for GABA, and anterograde labeling with biotinylated dextranamine. Immunohistochemistry displayed that only GABA immunoreactive terminals were observed in the thalamic nucleus submedius, while GABA immunoreactive neuronal cell bodies were located in the thalamic reticular nucleus and lateral geniculate nucleus. Injection of Fluoro-Gold into the thalamic nucleus submedius resulted in massive retrogradely labeled neuronal cell bodies in the rostroventral portion of the ipsilateral thalamic reticular nucleus and a few in the contralateral thalamic reticular nucleus, and most of these cell bodies showed GABA immunopositive staining. Many biotinylated dextranamine anterogradely labeled fibers and terminals in the thalamic nucleus submedius were observed after injection of biotinylated dextranamine into the thalamic reticular nucleus.
The generally predominant injury of the lateral aspect of the thalamus included reticular nucleus and ventral nuclei.
Additional subtelencephalic cell groups showing prominent labeling included the thalamic reticular nucleus and ventral lateral geniculate nucleus of the diencephalon, the nucleus pretectalis, subpretectalis and spiriformis lateralis of the pretectum, and the magnocellular isthmic nucleus of the optic lobe.
The nuclei of the dorsal thalamus and reticular nucleus in humans were found to contain separated NADPH-diaphorase (NADPH-d)-positive neurons. Thus, NADPH-d-positive cells of the dorsal thalamus, reticular nucleus, and internal capsule were evolutionarily more ancient and less structurally complex cells..
As compared with the distributions of p47Phox, gp91Phox in mouse, some differences in the rat brain were observed in the hippocampus, thalamus, amygdala, reticular nucleus, and basal ganglia.
In particular, during our study we observed a consistent involvement of the lateral geniculate body, the lateral posterior, ventral anterior, ventral lateral, ventral posterior lateral, and ventral posterior medial thalamic nuclei as well as the extraterritorial reticular nucleus.
In addition, ATF3-positive cell nuclei were found in the thalamic reticular nucleus (TRN) and medial geniculate nuclear complex (MGN), from which most regenerating axons originate.
Since P15, neurodegeneration was observed additionally in midline, ventral and caudal thalamic nuclei (visual and auditory thalamic nuclei), in the lateral posterior and in the reticular nucleus.
This impairment was accompanied by, and correlated with, decreases in expression of zif-286 in the infralimbic cortex and of parvalbumin in the dorsal reticular nucleus of the thalamus.
In the thalamus, c-fos mRNA expression was detected in the midline nuclei and in the reticular nucleus but not in the dorsomedial nucleus.
In addition, strong hybridization signals were localized in various nuclei: main and accessory olfactory bulb, compact part of the substantia nigra, pontine gray matter, tegmental reticular nucleus, Edinger-Westphal nucleus, trigeminal motor nucleus, locus coeruleus, mesencephalic trigeminal nucleus, raphe nuclei, facial nucleus, ambiguus nucleus, dorsal motor vagal nucleus, and inferior olivary nucleus.
RESULTS: It was observed that stimulants had the affect of significantly reducing the parameter controlling activation in the intrathalamic pathway involving the thalamic reticular nucleus (TRN) and the parameter controlling excitatory cortical activity.
Immunoreactive fibers of varying density were noted in bed nucleus of stria terminalis, septal nuclei, nucleus accumbens, caudate putamen, diagonal band, amygdala, hypothalamus, zona incerta, thalamus, periaqueductal gray, raphe nuclei, lateral parabrachial nucleus, locus coeruleus, spinal trigeminal tract, rostral ventrolateral medulla, and medullary reticular nucleus.
These activities are essentially generated by the activity of the thalamo-cortical relay neurons, the neurons of the thalamic reticular nucleus and by the neurons in the cerebral cortex.
This paper proposes that such an integration can be understood under the framework of analogy and that part of the thalamus and the thalamic reticular nucleus (TRN) may be playing a key role in this respect.
Furthermore, DJ-1 mRNA was also highly expressed in non-motor structures including the hippocampus, the olfactory bulb, the reticular nucleus of the thalamus, and the piriform cortex.
In the thalamus of the rat the reversal potential of GABA-induced anion currents is more negative in relay cells than in neurones of the reticular nucleus (nRt) due to different chloride extrusion mechanisms operating in these cells.
On the basis of theoretical, anatomical, psychological and physiological considerations, Francis Crick (1984) proposed that, during selective attention, the thalamic reticular nucleus (TRN) controls the internal attentional searchlight that simultaneously highlights all the neural circuits called on by the object of attention.
OBJECTIVE: Auditory neurons have been identified in the caudoventral part of the thalamic reticular nucleus (TRN).
The IPSP responses to both acoustic stimuli and electrical cortical stimulation are likely to be caused by feedback from the thalamic reticular nucleus..
The cells of the reticular nucleus expressed GAD67 and PARV from 12 g.w.
The following major afferent nuclei to Vd/Vv were identified: medial and posterior pallial zones of dorsal telencephalic area, and the subpallial supracommissural and postcommissural nuclei of the ventral telencephalic area, the olfactory bulb, dorsal entopeduncular, anterior and posterior parvocellular preoptic and suprachiasmatic nuclei, anterior, dorsal and central posterior dorsal thalamic, as well as rostrolateral nuclei, periventricular nucleus of the posterior tuberculum, posterior tuberal nucleus, various tuberal hypothalamic nuclei, dorsal tegmental nucleus, superior reticular nucleus, locus coeruleus, and superior raphe nucleus. Regarding ascending activating/modulatory systems, the pallium shares with the subpallium inputs from the (noradrenergic) locus coeruleus, and the (serotoninergic) superior raphe, while the subpallium additionally receives such inputs from the (dopaminergic) posterior tuberculum, the (putative cholinergic) superior reticular nucleus, and the (putative histaminergic) caudal hypothamalic zone..
Neuronal cell bodies containing ChAT are present in the telencephalon (lateral nucleus of ventral telencephalic area), preoptic region (anterior/posterior parvocellular and magnocellular preoptic nuclei), diencephalon (habenula, dorsal thalamus, posterior tuberculum), mesencephalon (Edinger-Westphal (EW) nucleus, oculomotor nerve nucleus, rostral tegmental nucleus, tectal type XIV neurons), isthmic region (nucleus lateralis valvulae, secondary gustatory-viscerosensory nucleus, nucleus isthmi (NI), perilemniscal nucleus, superior reticular nucleus (SRN)) and rhombencephalon (trochlear, trigeminal, abducens, facial, glossopharyngeal-vagal motor nerve nuclei, rostral and caudal populations of octavolateralis efferent neurons).
Thus, NADPH-d-positive cells of dorsal thalamus, reticular nucleus and capsula interna appear to be evolutionally more ancient and structurally less complex..
Collaterals of labeled axons produced slabs of terminal field in the thalamic reticular nucleus, which also exhibited a weak topography of distribution.
The thalamic reticular nucleus (nRt) is innervated by dopaminergic projections from the sustantia nigra compacta (SNc) and is rich in dopamine D4 receptors, however, the functional effects of dopamine on this structure are unknown.
The inhibitory neurons of the thalamic reticular nucleus (TRN) contribute to the generation of widespread oscillations in the thalamocortical system.
Extracellular neuronal responses were recorded from the posterior insular cortex following electrical and chemical stimulation of the thalamic reticular nucleus (Rt) regions.
Intracellular recordings were made from neurones in the thalamic reticular nucleus (TRN) and ventro-basal (VB) thalamus in slices of rat midbrain in vitro.
Mutual inhibition between the GABAergic cells of the thalamic reticular nucleus (RTN) is important in regulating oscillations in the thalamocortical network, promoting those in the spindle range of frequencies over those at lower frequencies.
Expression of connexin-36 immunoreactivity is widespread in the forebrain and significantly enhanced in the barrel cortex and thalamic reticular nucleus during the second postnatal week, but it extends to other thalamic nuclei as well.
He did not observe any projections of the thalamic reticular nucleus towards the cerebral cortex, a fact that has been corroborated using modern-day techniques.
In the thalamus, positively labeled neurons were detected in the reticular nucleus with ERG1 and ERG3 and in the anterodorsal nucleus with ERG2 riboprobes.
Through radial and tangential migration, these pioneer neurons and fibers can approach the differentiating field of the ganglionic eminence, the subplate and thalamic reticular nucleus to participate in the formation of these three intermediate targets. Furthermore, the subplate, ganglionic eminence and thalamic reticular nucleus are linked by pioneer neurons and fibers to form a guidance axis. The concept of a "waiting time" in the subplate and the thalamic reticular nucleus is likely due to the expression of a guidance effect, so that the thalamocortical and corticothalamic projections can be deployed spatially and temporally to the subplate and thalamic reticular nucleus before these projections enter their final destinations, the neocortex and thalamus..
The thalamic reticular nucleus (TRN) forms an essential part of the circuits that link the thalamus to the cortex, whereas the perireticular thalamic nucleus (PRN) consists of scattered neurons that are located in the internal capsule, in close relation to the TRN.
Relay neurons of the lateral geniculate nucleus innervate visual cortex, but they also provide axonal collaterals to neurons in the thalamic reticular nucleus, and these thalamic reticular neurons provide feedback inhibition to relay cells.
However, the GluR5 agonist ATPA reduced the IPSPs originating from the thalamic reticular nucleus. This action of the antagonist was occluded when GABA receptors were blocked, indicating that the reduction in excitatory sensory responses by LY382884 is due to an action on GABAergic inhibition arising from the thalamic reticular nucleus. We suggest that GluR5 is located presynaptically on inhibitory GABAergic terminals of thalamic reticular nucleus neurones, and that it is normally activated by glutamate spillover from synapses between excitatory afferents and relay neurones during physiological stimulation.
NT-4 immunoreactivity was strong in large neurons of the red nucleus and pontine reticular nucleus as well as the locus coeruleus, and moderate in cells in the mesencephalic trigeminal nucleus and interstitial nucleus of the medial longitudinal fasciculus.
Brain areas that receive a strong to moderate input from the BSTrh fall into nine general categories: central autonomic control network (central amygdalar nucleus, descending hypothalamic paraventricular nucleus, parasubthalamic nucleus and dorsal lateral hypothalamic area, ventrolateral periaqueductal gray, lateral parabrachial nucleus and caudal nucleus of the solitary tract, dorsal motor nucleus of the vagus nerve, and salivatory nuclei), gustatory system (rostral nucleus of the solitary tract and medial parabrachial nucleus), neuroendocrine system (periventricular and paraventricular hypothalamic nuclei, hypothalamic visceromotor pattern generator network), orofaciopharyngeal motor control (rostral tip of the dorsal nucleus ambiguus, parvicellular reticular nucleus, retrorubral area, and lateral mesencephalic reticular nucleus), respiratory control (lateral nucleus of the solitary tract), locomotor or exploratory behavior control and reward prediction (nucleus accumbens, substantia innominata, and ventral tegmental area), ingestive behavior control (descending paraventricular nucleus and dorsal lateral hypothalamic area), thalamocortical feedback loops (medial-midline-intralaminar thalamus), and behavioral state control (dorsal raphé and locus coeruleus).
The advance of knowledge of the thalamic reticular nucleus and its connections has been reviewed and Max Cowan's contributions to this knowledge and to the methods used for studying the nucleus have been summarized. Since it appears that all areas of cortex and all parts of the thalamus are linked directly to the reticular nucleus, it now becomes important to define how the several pathways that pass through the thalamus relate to each other in their reticular connections..
Thalamic projections from Rgb target the anteroventral and laterodorsal nuclei of the thalamus, with only a few axons terminating in the anterodorsal nucleus, the reticular nucleus, and the nucleus reuniens of the thalamus.
On the other side, the thalamocortical resonant loops of the non especific nuclei, particularly the intralaminar, connect with theapical dendrites of layer 1 pyramids whose discharge go to the thalamic relay neurones directly and through the reticular nucleus.
GABA neurons of ventral thalamus (reticular nucleus, ventral lateral geniculate nucleus, zona incerta, and nucleus of the fields of Forel) and of epithalamus appear at least 14 days before those intrinsic to dorsal thalamus. Neurons continue to be added to the ventral thalamus, perireticular nucleus, entopeduncular nucleus, and substantia nigra from the ganglionic eminence as development proceeds.
We studied here the effect of stimulations in the thalamic reticular nucleus (TRN) on the development of seizures and hippocampal hyperexcitability in kindling elicited from the ventral hippocampus in rats.
Regenerating neurons were found in the thalamic reticular nucleus and deep cerebellar nuclei of animals that received living grafts.
Networks of interconnected inhibitory neurons, such as the thalamic reticular nucleus (TRN), often regulate neural oscillations.
Two GABA(A) receptor ligands, [ (3)H]muscimol and [ (3)H]flunitrazepam, were used to study the distribution and binding properties of the receptor in intact monkeys, those with kainic acid lesions in the globus pallidus, and those with ibotenic acid lesions in the reticular nucleus using quantitative autoradiographic technique on cryostat sections of fresh frozen brain tissue. One week after the reticular nucleus lesioning, the binding densities of [ (3)H]muscimol and [ (3)H]flunitrazepam were decreased in the thalamic nuclei receiving projections from the lesioned reticular nucleus sector by approximately 50% (P<0.05) and 10-33% (P<0.05), respectively.
The reciprocal synaptic relationship between the relay thalamus and surrounding thalamic reticular nucleus can lead to the generation of various rhythmic activities that are associated with different levels of behavioral states as well as certain pathophysiological conditions. Using intracellular recording techniques, we found that VIP selectively depolarized relay neurons in the ventrobasal nucleus but had negligible actions on neurons in thalamic reticular nucleus.
Simultaneous multiunit recordings were collected in auditory cortex, auditory thalamus, and the auditory sector of the reticular nucleus of restrained rats, which spontaneously shifted from waking (W) to slow-wave sleep (SWS) and paradoxical sleep (PS).
Numerically, its synapses dominate the inputs to relay cells and to the gamma-amino butyric acid (GABA)ergic cells of the reticular nucleus (RTN).
In contrast to the distribution observed in retinorecipient zones, most or all neurons were doubly stained for NAAG and GAD(67) in the thalamic reticular nucleus. These findings suggest a complicated picture in which NAAG and GABA are segregated in distinct neuronal populations in primary visual targets, yet they are colocalized in neurons of the thalamic reticular nucleus.
Later components of the thalamic response, which are likely to coincide with arrival of inhibitory inputs from the thalamic reticular nucleus and excitatory inputs from the barrel cortex itself, are variable and poorly predicted by stimulus parameters.
The visual sector of the thalamic reticular nucleus is the source of the primary inhibitory projection to the visual thalamic relay nucleus, the dorsal lateral geniculate nucleus. The purpose of this study was to investigate laminar and cellular targets of individual thalamic reticular nucleus axons in the highly laminated lateral geniculate nucleus of the prosimian primate Galago to better understand the nature and function of this projection. Reconstructed thalamic reticular nucleus axons were narrowly aligned along a single axis perpendicular to the geniculate laminar plane, exhibiting a high degree of visuotopic precision. These results suggest that cells in the visual thalamic reticular nucleus influence the lateral geniculate nucleus retinotopically, with little regard to visual functional streams..
We demonstrate here that chronic intermittent exposure to PCP (2.58 mg kg(-1) i.p.) elicits a metabolic hypofunction, as demonstrated by reductions in the rates of glucose utilization, within the prefrontal cortex, reticular nucleus of thalamus and auditory system, key structures displaying similar changes in schizophrenia. Moreover, chronic PCP treatment according to this regime also decreases parvalbumin mRNA expression in the rat prefrontal cortex and reticular nucleus of the thalamus. Clozapine, but not haloperidol, reversed PCP-induced decreases in parvalbumin expression in prefrontal cortex GABAergic interneurons, whereas both drugs reversed the deficits in the reticular nucleus of the thalamus.
These latter areas are known as nociceptive afferent pathways to supra-spinal structures such as the medulla reticular nucleus and the thalamus.
The thalamic reticular nucleus (nRT) is composed entirely of GABAergic inhibitory neurones that receive input from pyramidal cortical neurones and excitatory relay cells of the ventrobasal complex of the thalamus (VB).
METHODS: Hippocampal electroencephalogram and single-unit activity in the thalamic reticular nucleus (nRT) were recorded in anaesthetized rats. RESULTS: Thalamic reticular nucleus neurons showed gated responses to paired-tone auditory stimuli, resembling hippocampal auditory gating.
Previous anatomical investigations have found that muscarinic type 2 receptors are densely distributed on the dendritic terminals of GABAergic interneurons, as well as the somata and proximal dendrites of GABAergic cells in the thalamic reticular nucleus.
Cells of the cat's perigeniculate nucleus (PGN), part of the visual sector of the thalamic reticular nucleus (TRN), provide GABAergic inhibition to the A and A1 layers of the dorsal lateral geniculate nucleus (LGNd) and, therefore, may control information flow from the retina to the cortex.
We studied the cerebellar connections to the reticular nucleus thalamus (RNT) by means of retrograde axonal transport of horseradish peroxidase (HRP) in the rat.
Especially in the medial septum and thalamic reticular nucleus, the receptor highly colocalized with parvalbumin-positive neurons.
The expression accounts for feedforward inputs from retina and intrageniculate interneurons as well as feedback inputs from cortex and the thalamic reticular nucleus and can be used to experimentally test different mechanistic models for the geniculate circuitry.
Irrespective of age, CO activity was reduced in three cerebellar-related regions of NFH-LacZ transgenic mice: (1) the lateral reticular nucleus, (2) the parvicellular red nucleus, and (3) the superior colliculus, possibly as a secondary consequence of cerebellar Purkinje cell histopathology.
Subcortical activations were found in cerebellum (particularly the vermis) and in the thalamus with the focus in a region comprising the lateral geniculate nucleus, the pulvinar, and adjacent parts of the reticular nucleus.
After kainate administration, increased proN/OFQ gene expression was observed in the reticular nucleus of the thalamus and in the medial nucleus of the amygdala.
Unlike the reticular nucleus, ZI receives peripheral and layer V cortical input but no thalamic feedback; it projects to brainstem centres and has extensive intranuclear recurrent collaterals.
Cells in the dorsal thalamus are strongly inhibited by the GABAergic cells of the thalamic reticular nucleus (TRN).
Parvalbumin, a calcium-binding protein located within a subpopulation of GABAergic interneurones, displayed altered mRNA levels within the reticular nucleus of the thalamus at 2 and 24 h posttreatment and the substantia nigra pars reticulata 24 h posttreatment only.
The "searchlight of attention" is activated as a result of resonance within the gamma frequency range, selectively enhancing cortical detectors and involving the reticular nucleus of the thalamus.
Neurons in the thalamic reticular nucleus and deep cerebellar nuclei transiently upregulated these mRNAs after axotomy, and showed prolonged upregulation of all three molecules when regenerating axons into peripheral nerve grafts inserted into the thalamus of cerebellum.
Large regions of the forebrain, including the striatum, thalamic reticular nucleus, hypothalamus, and basal forebrain showed little or no NgR expression.
In all three primates, DL/MT(C) had reciprocal connections with the pulvinar and claustrum; received afferents from the locus coeruleus, dorsal raphe, nucleus annularis, central superior nucleus, pontine reticular formation, lateral geniculate nucleus, paracentral nucleus, central medial nucleus, lateral hypothalamus, basal nucleus of the amygdala, and basal nucleus of Meynert/substantia innominata; and sent efferents to the pons, superior colliculus, reticular nucleus, caudate, and putamen.
Located between the thalamus and cortex is a thin lamina of neurons called the thalamic reticular nucleus (Rt). The thalamic reticular nucleus projects exclusively to thalamus, thus forming an essential component of the circuitry mediating sensory transmission.
This presentation outlines modern methods for identifying classes of thalamic neurons, their chemical characteristics, synaptology and differential connections, and describes the intrinsic circuitry of the thalamus, showing how interactions between GABAergic cells of the reticular nucleus and glutamatergic relay cells underlie rhythmic activities of neurons in the thalamo-cortico-thalamic network, activities associated with changes in the conscious state, and which are generated and maintained by the corticothalamic projection. Corticothalamic fibers interact with reticular nucleus cells and relay cells through NMDA, AMPA and metabotropic receptors while interactions between reticular nucleus cells and relay cells are mediated by GABAA and GABAB receptors.
RESULTS: Increased proOFQ/N mRNA levels were found in the thalamus (reticular nucleus) after kainate administration.
Due to its strategic position, the thalamic reticular nucleus (TRN) plays an important role within the thalamo-cortical circuits.
We examined the effects of somatostatin (SST) on neurons in the thalamic reticular nucleus (RT) using whole-cell patch-clamp techniques applied to visualized neurons in rat thalamic slices.
OBJECTIVES: The aim of this study was to investigate the effects of bilateral chemical lesion of the rostral pole of the thalamic reticular nucleus on EEG activities in freely moving rats applying quantitative analysis and brain mapping of power spectra distribution.METHODS: Ketamine-sedated Sprague-Dawley rats were implanted to monitor behavioral states with frontoparietal electrodes in a first series of experiments and with multiple electrodes along the antero-posterior axis (F1, F2, F7, F8, T3, T4, P3, P4) in a second series. Monopolar and bipolar recordings were obtained in animals stereotaxically injected with ibotenic acid into both rostral poles of the thalamic reticular nucleus.
Such 'gating' involves inhibition of the thalamocortical relay neurons by the reticular nucleus of the thalamus, but the underlying mechanisms are poorly understood.
The authors report here electrophysiological and autoradiographic results obtained after muscimol injection (1 microg/microl) either into the nucleus basalis magnocellularis (0.1-0.4 microl) or into the thalamic reticular nucleus (RE, 0.05-0.1 microl).
In the reticular nucleus of the rat thalamus, about 30% of the synapses are brought about by the perikarya of parvalbumin-immunopositive neurons, which establish somato-dendritic synapses with large dendrites of nerve cells of specific thalamic nuclei. It is assumed that the peculiar somato-dendritic synaptic complexes subserve the goal of filtration of impulses arriving at the reticular nucleus from various thalamic nuclei, thus processing them for further sampling..
Briefly, H1 and H3 receptor mRNAs were relatively enriched in the anterior, medial, and part of the lateral nuclei regions; whereas the expression level was much lower in the ventral and posterior parts of the thalamus, and the reticular nucleus.
The thalamic reticular nucleus (nRt) provides an important inhibitory input to thalamic relay nuclei and is central in the generation of both normal and abnormal thalamocortical activities.
The fastigial nucleus innervates a large number of autonomic and motor structures in the brainstem and diencephalon, including the ventrolateral nucleus of the thalamus and the gigantocellular reticular nucleus in the medulla--structures that have been implicated in human posthypoxic myoclonus (6, 7).
The aim of this study was to demonstrate the effect of administration of gamma-aminobutyric acid (GABA)(A) receptor antagonist, bicuculline, into the reticular nucleus of the thalamus (nRt) on spike and wave discharges (SWD) and cardiovascular regulation in conscious rats with genetic absence epilepsy.
Anteroventral nucleus had decreased ACh content after PPTg lesion, but a time dependent increase was found in mediodorsal nucleus; ACh concentration was unchanged in thalamic reticular nucleus or medial geniculate.
Here we build on that model by embedding it into a wider circuit containing the motor thalamocortical loop and thalamic reticular nucleus (TRN).
The first system is centred on the projection from deep laminae to three caudal reticular areas - the lateral reticular nucleus (LRN), the subnucleus reticularis dorsalis (SRD) and the gigantocellular lateral paragigantocellular reticular nuclei (NGc) - and the parabrachial internal lateral subnucleus (PBil).
We have found that cells in the ferret thalamic reticular nucleus (TRN) express brain nitric oxide synthase (bNOS) in a transient pattern during early postnatal development.
Neurons of the thalamic reticular nucleus (TRN) provide inhibitory input to thalamic relay cells and generate synchronized activity during sleep and seizures.
Postsynaptic and presynaptic effects of nociceptin/orphanin FQ (N/OFQ), the endogenous ligand of the opioid-like orphan receptor, were investigated in an in vitro slice preparation of the rat thalamic reticular nucleus (NRT) and ventrobasal complex (VB).
Labeled terminal fibers, evidencing bilateral efferent paratrigeminal projections were observed in the medial and caudal solitary tract (sol), lateral reticular nucleus (LRt), ambiguus nucleus (Amb), rostroventrolateral reticular nucleus (RVL), while ipsilateral projections were found in the parabrachial (PB) nuclei and ventral portion of the ventral posteromedial thalamic nucleus (VPM).
Voltage-sensitive dye imaging of mouse thalamocortical slices demonstrated that electrical stimulation of the centrolateral intralaminar thalamic nucleus (CL) resulted in the specific activation of thalamic reticular nucleus, striatum/putamen, and cortical layers 5, 6, and 1.
A major inhibitory input to the dorsal thalamus arises from neurons in the thalamic reticular nucleus (TRN), which use gamma-aminobutyric acid (GABA) as a neurotransmitter.
It is suggested that the reticular nucleus of the thalamus plays a pivotal role in anticipatory attention..
These simulation studies revealed that this antagonistic ERD/ERS phenomenon depends on the functional interaction between the populations of thalamo-cortical cells (TCR) and reticular nucleus cells (RE) and on how this interaction is modulated by cholinergic inputs.
To determine kinetic, pharmacological, and structural properties of thalamic gamma-aminobutyric acid type A (GABA(A)) receptors, we used patch-clamp techniques and single-cell reverse transcriptase polymerase chain reaction (RT-PCR) in neurons from two principal rat thalamic nuclei-the reticular nucleus (nRt) and the ventrobasal (VB) complex.
In adult thalamus, chondroitin sulfate proteoglycans of high molecular mass, bearing glycosaminoglycans unsulfated in the linking region, and recognized by antibody 1-B-5 are confined to perineuronal nets around neurons chiefly localized in thalamic reticular nucleus. Double-immunolabeling has shown that, along the rostrocaudal extension of reticular nucleus, the most developed perineuronal nets are associated with a subset of neurons expressing calretinin, and not with parvalbumin-positive neurons, which represent the largest neuronal population of the nucleus. The distribution of perineuronal nets supports the presence, in thalamic reticular nucleus, of neuronal subpopulations with different morphological and physiological features..
The thalamic reticular nucleus is a key region in selective attention, effecting a change in the mode of thalamocortical transmission. Each major thalamocortical system is connected with a particular sector of the thalamic reticular nucleus. No connections from the thalamic reticular nucleus have been described to the visceral sensory thalamus. We used axonal tracing techniques to study the possible existence of reciprocal connections between the visceral sensory relay in the lateral ventroposterior parvicellular thalamic nucleus, and the reticular nucleus of the thalamus. We also studied the projections from the visceral sensory cortex, located in the granular insular cortex in the rat, to the reticular nucleus of the thalamus. We found a convergent input from both thalamic and cortical sensory visceral regions to the same sector of the reticular nucleus of the thalamus.
Previous results from this laboratory demonstrated that the visual sector of the GABAergic thalamic reticular nucleus is selectively c-fos activated in rats that are naturally paying attention to features of a novel-complex environment, and that this activation is dependent on top-down glutamatergic inputs from the primary visual cortex. By contrast, the acoustic sector of the thalamic reticular nucleus is not activated despite noise generated by exploration and c-fos activation of brainstem acoustic centers (e.g.
Extracellular single unit recordings were made in the medial and lateral ventroposterior nucleus, posterior thalamic nucleus, zona incerta, lateral posterior nucleus, laterodorsal nucleus, ventrolateral nucleus and reticular nucleus.
Thalamic slice preparations, in which intrathalamic connectivity between the reticular nucleus and relay nuclei is maintained, are capable of sustaining rhythmic burst firing activity in rodents and ferret.
After localized injection of BDA into the Mx, labeled CT axons were found ipsilaterally in the thalamic reticular nucleus (TRN), the ventroanterior-ventrolateral complex (VA-VL), the central lateral nucleus (CL), the central medial nucleus, and the centromedian nucleus, but with the primary focus in the VA-VL.
The PrRP mRNA was expressed in the nucleus of the solitary tract (NTS) at embryonic day 18 (E18) and in the ventral and lateral reticular nucleus (VLRN) of the caudal medulla oblongata at E20. PrRP fibers were also found in the optic chiasm, dorsal endopiriform nucleus, cingulum, intermediate reticular nucleus, and caudal ventrolateral reticular nucleus at P6 and P9.
Our study revealed significant differences with regard to the central CCK system of the FH compared to the WKY rat, including differences in CCK-A receptor binding throughout the dorsal medulla, and altered CCK-B binding density throughout the cerebral cortex and reticular nucleus of the thalamus.
Training-related increases common to both age groups were found in the orbital frontal cortex, limbic thalamus, gigantocellular reticular nucleus, the somatosensory system, and cerebellum.
These findings corroborate both the hypothesis of a frontal modulation of brain-stem activation probably via the reticular nucleus of the thalamus and of a coactivation of the posterior attention system involved in spatial orienting by the anterior alerting network.
Inhibition of NMDA receptors on GABAergic thalamic reticular nucleus neurons might activate thalamocortical 'injury' circuits in animals.
Low-frequency thalamocortical oscillations that underlie drowsiness and slow-wave sleep depend on rhythmic inhibition of relay cells by neurons in the reticular nucleus (RTN) under the influence of corticothalamic fibers that branch to innervate RTN neurons and relay neurons.
Five regions of interest (CA1 and CA3 sector of hippocampus, dentate gyrus, reticular nucleus of thalamus and parietal cortex) where studied by light and electron microscopy at each of the survival times, and compared with non-ischemic control rats. Ischemic cell changes consisting of cytoplasmic condensation and nuclear pyknosis appeared in these regions on day 7 and --to a lesser degree-- also affected dentate gyrus, the reticular nucleus of thalamus and cerebral cortex.
We have examined the patterns of Fos-like immunoreactivity in the ventral thalamus (thalamic reticular nucleus (Rt), zona incerta (ZI) and ventral lateral geniculate nucleus (LGv)) after electrical or chemical stimulation of nuclei in either the brainstem (midbrain reticular nucleus), basal forebrain (substantia innominata) or dorsal thalamus (parafascicular nucleus).
In the thalamus, there was a trend for reduced [ (3)H]nicotine binding in the majority of nuclei (0-20%) in Alzheimer's disease; however, there was a significant decline in [ (125)I]alpha-bungarotoxin binding in the reticular nucleus.
Interposed between the dorsal thalamus and cortex are the GABAergic neurons of the thalamic reticular nucleus (TRN), which play a pivotal role not only in switching between the awake and sleep states but also in sensory processing during the awake state.
Rats with cytotoxic lesions of the rostral pole of the thalamic reticular nucleus were compared with surgical control animals on a series of spatial learning and memory tests. Subsequent experiments found no evidence that lesions of the rostral reticular nucleus affected the acquisition or performance of tests in the radial arm maze and the Morris water maze. Thus, it appears that the rostral pole of the thalamic reticular nucleus often does not play a necessary role in the performance of tests of spatial learning and memory, in spite of its interconnections with other regions that are required for normal spatial memory..
In thalamus, all three drugs increased GAD expression in the reticular nucleus, whereas only haloperidol decreased GABA(A) binding in the mediodorsal nucleus, actions consistent with a reduction in nigrothalamic, GABA-mediated neural transmission. These results are consistent with the idea that the two new antipsychotics tested have mild and regionally restricted actions within the basal ganglia nuclei and a common action on increasing GAD expression in the reticular nucleus of the thalamus (RtN).
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