(1) Neurogenesis occurred in the stratum Griseum Centrale of the tectum opticum from S11-12 to S16 with a peak at S12. 
Regenerating optic nerve axons projected into the stratum opticum-stratum fibrosum et griseum superficiale by week 2, the stratum Griseum Centrale by week 4, and stratum album centrale by week 6.
In the optic tectum, immunoreactivity to carnosine/carnosine-related dipeptides is present in neurons of the stratum album and the stratum Griseum Centrale.
Using histochemical determination of activity of the mitochondrial oxidative enzyme cytochrome oxidase (CO) in brain structures, metabolic activity both in turtles and in lizards has been shown to be higher in centers of the tectofugal channel (the tectal stratum Griseum Centrale, SGC; nucleus pretectalis ventralis, Ptv; thalamic nucleus rotundus, Rot; telencephalic visual area of the anterior dorsal ventricular ridge, Advr) than in the thalamofugal channel centers (the thalamic nucleus geniculatus lateralis pars dorsalis, GLd; cortex dorsolateralis, Cxdl; and pallial thickening, Path) of the visual system.
GnRH-ir axons overlapped central projections of retinal ganglion cell axons primarily within the stratum album centrale and stratum Griseum Centrale of the tectum in all species, and were concentrated in several diencephalic visual processing centers.
The somata in the stratum periventriculare were pyriform with an apical dendrite that ramified at the boundary zone between the stratum Griseum Centrale and stratum fibrosum et griseum superficiale.
One of them had an apical dendrite ramifying at the stratum fibrosum et griseum superficiale (SFGS), with an axon that bifurcated into two branches at the stratum Griseum Centrale (SGC), and the other had an apical dendrite ramifying at the SGC.
The chick optic tectum displays an alternating pattern of cellular and plexiform layers and at embryonic day (ED) 12 there are mainly four cellular layers: transient cell compartment 3 (TCC3), compartment "h-i-j"(C"h-i-j"), stratum Griseum Centrale (SGC) and subventricular zone (SvZ).
For an important type of tectal wide-field neuron, the stratum Griseum Centrale type I (SGC-I) neuron, we quantified its structure and found a spatially sparse but extensive sampling of the retinal projection.
The inclusions were located within cholinergic and other neurons in the pedunculopontine nucleus, cuneiform nucleus, and Griseum Centrale mesencephali and stained positively for ubiquitin, torsinA, and the nuclear envelope protein lamin A/C.
At 1 month stage, positive cells were detected in the hypothalamus, nucleus of the medial longitudinal fascicle (nMlf), rhombencephalic Griseum Centrale (Gc) and pituitary pars distalis.
The layers of the optic tectum, the projection neurons in the stratum Griseum Centrale, and the tectofugal pathways show differential OL-protocadherin immunoreactivity.
However, the distribution and shape of stained cells of the tectum stratum were distinct from those in other regions: Nissl-stained neurons were ubiquitously present throughout all cellular layers including the stratum Griseum Centrale, the stratum album centrale (SAC), and the stratum periventriculare (SP).
After an injection of WGA-HRP into the Rt, labelled neurones were observed in the striatum Griseum Centrale (SGC) in both sides of the tectum (TO) and in the ipsilateral nucleus subpretectalis/nucleus interstito-pretecto-subpretectalis (SP/IPS).
All three MAPs were expressed in large multipolar neurons in the developing stratum Griseum Centrale from the beginning of maturation.
They had superficial spiny dendrites, with a fan-shaped branching pattern in SM and a thick basal dendrite that gave rise to bushy horizontal branches at the boundary between the SFGS and the stratum Griseum Centrale (SGC), where an axon and a thin dendrite arose.
While the astrocytes were mainly found in the stratum opticum (SO), stratum album centrale (SAC) and stratum fibrosum periventriculare (SFP), with their processes extending throughout the entire optic tectum region, the oligodendrocytes were mainly scattered in the SO, stratum Griseum Centrale (SGC) and SAC.
The ipsilateral Rot received the most massive tectal projections, stemming from numerous neurons located in the stratum Griseum Centrale (SGC).
Without retinal input, neurons in the stratum Griseum Centrale express their specific cell adhesions molecules, retain large dendritic fields and form specialized dendritic endings; however, the latter are deformed and extend over a much larger area.
After BDA injections into nucleus rotundus, retrogradely labelled neurons were observed consistently within the following neuronal groups in the midbrain and the diencephalon: (i) the stratum Griseum Centrale of the optic tectum; (ii) the nucleus subpretectalis in the pretectum; (iii) the nucleus ansa lenticularis posterior, the posterior nucleus of the ventral supraoptic commissure, and the posteroventral nucleus, in the dorsal thalamus and (iv) the lateral suprachiasmatic nucleus and part of the reticular complex in the ventral thalamus.
In the mesencephalon, the optic tectum received a rich TRHir innervation between the periventricular gray zone and the stratum Griseum Centrale.
The electrophysiological and morphological features of visually driven neurons of the stratum Griseum Centrale of the zebra finch optic tectum were studied by extracellular recording and staining techniques. Stratum Griseum Centrale neuron responses are sustained in most cases. Anatomically, stratum Griseum Centrale neurons are characterized by far reaching dendrites which terminate with "bottlebrush"-like endings in the upper retinorecipient layers.
Six nonreticular nuclei (Griseum Centrale rhombencephali, n.
At least three identified cell types in the stratum Griseum Centrale (SGC) of the chick optic tectum mediate separate pathways from the retina to different subdivisions of the thalamic nucleus rotundus.
Neurons in the tectal stratum Griseum Centrale were found to be suited to deliver an alignment signal from the visual midbrain to the auditory pathway.
In the tectorotundal system, neurons of the stratum Griseum Centrale (SGC) of the optic tectum send their axons bilaterally to the nucleus rotundus (Rt).
In all layers of the optic tectum GP activity was found, but CO only labelled the stratum Griseum Centrale.
The majority of tectal neurons were located in the stratum Griseum Centrale.
In some layers, subpopulations of neurons differentially express the cadherins, e.g., in the stratum Griseum Centrale.
It originates predominantly from neurons in the ventromedial part of stratum Griseum Centrale and to a lesser extent from stratum album centrale.
Application of parvalbumin and calbindin immunohistochemistry and nicotinamide adenine dinucleotide phosphate-diaphorase histochemistry reveals the following lamination pattern: The stratum opticum, stratum Griseum Centrale and stratum album centrale remain unstained, while the laminae of the stratum griseum et fibrosum superficiale exhibit a roughly complementary staining pattern of calbindin (laminae c, d, e, f, g, i) and parvalbumin (laminae a, h, i). The Golgi material reveals the following cell types in the stratum griseum et fibrosum superficiale: marginal cells in the stratum opticum and in lamina h and i, horizontal cells in laminae a and c, large and small radial cells in laminae b, d, h and i, multiform cells in lamina b, bitufted cells in lamina d and e, large pear-shaped cells in lamina g, wide-field cells in lamina j, and stellate cells in lamina j and in the stratum Griseum Centrale.
They defined two distinct subpopulations of tectal neurons projecting from the stratum Griseum Centrale (SGC; tectal layer 13) to specific divisions of the rotundus.
In particular, cell bodies reacting only with Leu-enkephalin antibodies were detected in the medial subpallium of the telencephalon, the Griseum Centrale, the reticular formation, the nucleus of the solitary tract, and the visceral sensory area of the rhombencephalon.
Both the ipsilateral and contralateral tectorotundal projections were found to be organised topographically in as much as different sublaminas of the stratum Griseum Centrale (SGC) project in an orderly manner to Rt and T.
Other regions with distinctly elevated mu-receptor concentrations are the stratum Griseum Centrale of the optic tectum and the preoptic area.
The stratum periventriculare demonstrated a large number of strongly labeled cells whereas in the strata album centrale and Griseum Centrale, and at the boundary between the strata Griseum Centrale and fibrosum et griseum superficiale, some scarce, weakly immunostained cells were observed.
A weak immunoreactivity is found in the rostral stratum marginale (SM), strong labelling of the neuropil is shown in a thin band in stratum opticum (SO), two bands in stratum fibrosum et griseum superficiale (SFGS) and two bands in stratum Griseum Centrale (SGC).
Other meso-diencephalic cell groups were the Griseum Centrale (including the n.
The projection to nucleus rotundus was found to arise exclusively from multipolar neurons of the stratum Griseum Centrale, while the projection to the geniculate nuclei was found to arise from radial cells with long ascending dendrites in the stratum griseum periventriculare. The crossed descending projection to the paramedian hindbrain was found to arise almost exclusively from large multipolar neurons, the majority of which were located in the stratum Griseum Centrale and some of which were located in the stratum griseum periventriculare. The ipsilateral descending projection was found to arise from multipolar neurons in the stratum Griseum Centrale and stratum griseum periventriculare, from radial and pyramidal neurons in the stratum griseum periventriculare, and from radial neurons in stratum griseum et fibrosum superficiale.
Neuronal transcriptional activity is found mostly in the glomerular layer of the olfactory bulb, in the striatum, nucleus accumbens septi, lateral and medial septal nuclei of the telencephalon, in the habenulae and various nuclei of the diencephalon, in the tectum opticum (particularly in the stratum Griseum Centrale), in the molecular layer of the cerebellum and in various nuclei of the rhombencephalon.
NADPH-d positive cells are arranged in three bands: the first band, in the stratum griseum et fibrosum superficiale, sublayer II a, is formed by small marginal and horizontal neurons; the second band is broad and extends throughout layers II i-j and III (stratum Griseum Centrale); the third band lies around the tectal ventricle, and consists of neurons in the stratum griseum profundum (SGP) and tanycytes.
A major descending projection originated from the Griseum Centrale (including the nucleus laminaris of the torus semicircularis), while minor areas of origin, apart from isolated reticular cells, were the nucleus and the interstitial nucleus of the fasciculus longitudinalis medialis, the red nucleus, the locus coeruleus and the raphe nuclei.
Large cell bodies located in the stratum Griseum Centrale were also stained..
However, the effects of colchicine and of TTX could be dissociated, since the most superficial tectal neurons became pyknotic only in response to colchicine, and, with a sufficiently short survival time (9 hr), the deep cells of the stratum Griseum Centrale became pyknotic only in response to TTX.
In the stratum fibrosum et griseum superficiale, stratum Griseum Centrale and stratum album centrale of the optic tectum, a moderate number of immunoreactive fibres was observed.
The cells displaying this secondary tangential migration appeared restricted to two strata (stratum Griseum Centrale (SGC) and stratum griseum et fibrosum superficiale (SGFS)).
Structures that contained high numbers of alpha 7-like immunoreactive (LI) somata included the intergeniculate leaflet, nucleus intercalatus thalami, nucleus ovoidalis, organum paraventricularis, nucleus rotundus, isthmic nuclei, nucleus trochlearis, oculomotor complex, nucleus interstitio-pretecto-subpretectalis, stratum Griseum Centrale of the optic tectum, and nucleus semilunaris. High numbers of beta 2-LI somata were found only in the nucleus spiriformis lateralis, whereas neuropil staining for beta 2-LI was intense in the nucleus geniculatus lateralis ventralis, nucleus suprachiasmaticus, nucleus lateralis anterior, nucleus habenularis lateralis, area pretectalis, griseum tecti, nucleus lentiformis mesencephalis, nucleus externus, and nucleus interpeduncularis, and in the stratum Griseum Centrale, stratum griseum et fibrosum superficiale, and stratum opticum of the tectum.
In gonadally intact quail brains, [ 3H] flunitrazepam displayed a heterogeneous distribution, with elevated levels in the posterior brain regions such as the stratum griseum et fibrosum superficiale and stratum Griseum Centrale of the optic tectum.
Correlations among a variety of neural structures suggested the importance of stratum marginale (SM), stratum opticum (SO), and stratum fibrosum et griseum superficiale (SFGS), stratum Griseum Centrale (SGC) and stratum periventriculare (SPV) in vision, of stratum album centrale (SAC) and SGC for olfaction, and of SPV for the processing of acoustico-lateral information..
Methionine- and leucine-enkephalin immunoreactive fibers were found in discrete sublayers in the following strata: stratum opticum, stratum fibrosum et griseum superficiale, stratum Griseum Centrale, stratum, and album centrale.
Terminal arborizations of contralaterally projecting visual fibres were identified in ten hypothalamic structures (area optica preoptica ventralis and the nuclei suprachiasmaticus, opticus hypothalamicus ventromedialis, preopticus magnocellularis lateralis, posterioris lateralis, posterioris dorsalis periventricularis posterioris dorsalis lateralis, posterioris dorsalis medialis, posterioris ventralis lateralis, and posterioris ventralis periventricularis), ten thalamo-pretectal structures (Areas C1 and C2, area optica tractus opticus ventrolateralis and the nuclei dorsolateralis thalami, ventrolateralis thalami pars ventralis, opticus ventralis thalami, geniculatus lateralis, opticus pretectalis partes dorsalis et ventralis, and opticus commissurae posterioris), and in the tectal strata opticum partes externa et interna, fibrosum et griseum superficiale, Griseum Centrale and album centrale.
Reciprocal direct connections were shown between the mamillary complex nuclei and hypothalamotegmental structures, on the one hand, and following structures in the brain stem, on the other hand: Griseum Centrale, n.
In tectum, Glu+ was also observed in torus longitudinalis granule cells, toral terminals in stratum marginale, some pyramidal neurons in the SFGS, multipolar and fusiform neurons in stratum Griseum Centrale, large multipolar and pyriform projection neurons in stratum album centrale, and many periventricular neurons.
The largest contingent of afferents to the ZI comes from the superior and inferior colliculus, Griseum Centrale, formatio reticularis mesencephali and nuclei tractus mesencephalici of the nerve trigemini, cuneatus, dentatus and interpositus.
Some labelled cell bodies were observed in the ipsilateral substantia Griseum Centrale and in the nucleus reticularis mesencephali.
reactive sublamina, a of stratum Griseum Centrale (SGCa), just subjacent to the SFGS, it was possible to measure the thickness of the SFGS following optic denervation and subsequent reinnervation.
Other medium-to-small optic terminals were found in stratum opticum a and b (60a,b), SFGSb, SFGSc, and stratum Griseum Centrale c (SGCc).
The contralateral fibres projected to the suprachiasmatic nucleus, the nucleus opticus dorsolateralis, the nucleus of the posterior commissure, the nucleus geniculatus lateralis, pretectal nuclear complex, and to two layers of the optic tectum, i.e., stratum fibrosum et griseum superficiale and stratum Griseum Centrale.
Retinofugal fibers are labeled in the stratum opticum (SO), stratum fibrosum et griseum superficiale (SFGS), stratum Griseum Centrale (SGC), stratum album centrale (SAC) and stratum periventriculare (SPV).
Neurons of the stratum Griseum Centrale were predominantly driven by electrosensory stimuli, most often those associated with the movement of an object, and generally were very sensitive to the direction of motion.
Solitary magnocellular neurons are described in the adult chick optic tectum on the basis of their large size, polygonal shape, intensely basophilic perikarya, characteristic position at the border between the stratum Griseum Centrale and the stratum album centrale, decreasing density along a rostrocaudal gradient, and intense activity of NADH-diaphorase. These characteristics distinguish this population from the adjacent ganglion cells of the stratum Griseum Centrale, which are more numerous, smaller, paler staining and have background levels of NADH-diaphorase. Moreover, the solitary magnocellular neurons appear unlabeled after tritiated-thymidine administration after stage 17+, and are thus born before the stratum Griseum Centrale neurons, which are generated after stage 19.
Six layers are readily distinguished: a fairly thick stratum marginale, a narrow stratum opticum and stratum fibrosum et griseum superficiale, a well-developed stratum Griseum Centrale, a stratum album centrale and a compact stratum periventriculare. A cell of stratum Griseum Centrale with an ascending axon to stratum opticum. A special projection type of fusiform cell of stratum Griseum Centrale, with an efferent axon of somatic origin. A cell rich stratum Griseum Centrale, with a wider variety of multipolar and bipolar cell population than reported in other teleosts.
A thin axon descends vertically from the soma and arborizes in vertical alignment with the cell's dendritic field in sublayer c of the stratum fibrosum et griseum superficiale and the upper third of the stratum Griseum Centrale. The type C neuron is a bipolar cell with a small, vertically fusiform soma situated at the upper border of the stratum Griseum Centrale. An axon arises from the soma and courses ventrally into the stratum Griseum Centrale where it gives rise to a plexus of widely spreading branches that extend medially from the cell's dendritic field. The type D neuron is a small, stellate cell with a spherical soma and fine, appendage-laden dendrites that are restricted to the stratum Griseum Centrale.
The axon gives rise to an intratectal, collateral arbor that extends horizontally into the stratum Griseum Centrale beyond the cell's dendritic tree.
In two cases of action myoclonus following hypoxic or shock encephalopathy, neuropathological examination disclosed mild or moderate scattered changes involving thalamus, Griseum Centrale mesencephali, and nucleus centralis superior. The last case of action myoclonus following acute methyl bromide intoxication was characterized by marked changes in the inferior colliculi and moderate or mild abnormalities of thalamus, Griseum Centrale mesencephali, nucleus centralis superior, nucleus reticularis tegmenti pontis, nuclei pontis, and dentatus.
In addition, a group of small catecholamine neurons was located in the Griseum Centrale mesencephali near the aqueduct.
Their axons had horizontal processes ramifying in the deepest lamina of SGFS or the stratum Griseum Centrale..
Some stained neurons were found in the midbrain in the stratum Griseum Centrale; the conclusion was made that the main sources of inputs to the studied area were different regions of the visual system or the structures of the brain closely connected with the latter..
Therefore, fine fibers were found to reach all target areas except the ipsilateral area ventralis lateralis, and these were the only fibers found in the lateral geniculate nucleus, area pretectalis, and stratum Griseum Centrale of the optic tectum.
HRP histochemistry shows that in addition to the retina, the basal optic complex is connected to three principal areas: the ipsilateral tegmental Griseum Centrale, the ipsilateral dorsal ventrolateral nucleus of the anterior thalamus, and the ipsilateral posterior thalamic nucleus.
Following HRP injections into the nucleus prethalamicus, pyriform neurons in the stratum periventriculare and stratum album centrale, and fusiform neurons in the stratum Griseum Centrale, were retrogradely labeled.
Moreover, specific layers (stratum marginale, stratum Griseum Centrale) in 100-day-old DR showed significant increase in the number of synaptic vesicles per nerve terminal..
In the midbrain a few labeled cells are found in the Griseum Centrale.
EPSPs of 72 cells in stratum fibrosum et griseum superficiale, stratum Griseum Centrale and stratum album centrale were examine. Monosynaptic EPSPs were recorded from 19 cells in stratum fibrosum et Griseum Centrale and stratum Griseum Centrale, which was consistent with anatomical findings..
The labeling of the optic fibers obtained following injection of either tritiated proline or HRP in either of the eyes showed the existence of a normal contralateral retino-tectal projection to strata opticum, fibrosum et griseum superficial (SFGS), Griseum Centrale, and album centrale.
Projections from several brainstem structures are described, including: Griseum Centrale (GCt), medial and lateral reticular formation (FRM and FRL), area ventralis of Tsai (AVT), n.
Such neurons shows an ascendant dendritic shaft, very developed in the stratum marginale, a thinner dendritic shaft in the basal pole and a descending axon that reaches the internal zones of the stratum Griseum Centrale.
parabrachialis; stratum Griseum Centrale), reduced the spike-discharges only insignificantly.
centralis, the mesodiencephalic periventricular gray (Griseum Centrale, n.
The contralateral optic fibers project to the nucleus opticus dorsolateralis, nucleus of the posterior commissure, nucleus geniculatus lateralis, pretectal nuclear complex, nucleus corticalis, stratum fibrosum et griseum superficiale (SFGS), and a few optic fibers extend into the stratum Griseum Centrale.
HRP staining confirmed these projections and revealed another projection to the stratum Griseum Centrale..
Different types of axon terminals were also labeled in the stratum marginale, stratum fibrosum and griseum superficiale and stratum Griseum Centrale.
Terminations were seen contralaterally in the suprachiasmatic nucleus, the dorsal and ventral lateral geniculate nuclei (extensive), the pretectal nuclei, including the nucleus posterodorsalis (a very heavy input), the nucleus lentiformis mesencephali, nucleus geniculatus pretectalis, and nucleus pretectalis, the superficial layers of the optic tectum, including the stratum zonale, the stratum opticum, the stratum griseum et fibrosum centrale and the upper portion of stratum Griseum Centrale, and the basal optic nucleus.
The caudal portion is juxtaposed to the subependyma, while the rostral part lies in the neuropil of the presumptive Griseum Centrale pontis.
S3, S4, S5, F1, and F2 terminals are limited mainly to SFGS and Stratum Griseum Centrale (SGC).
The stratum marginale (SM) is especially impressive in this fish and contains dendrites of pyramidal neurons, marginal fibers from torus longitudinalis, and axon-like processes (the SM ascending axons) from cells located in the stratum Griseum Centrale (SGC).
These two labelling techniques have made it possible to determine two categories of structures connected with A.P.: those with afferent connections (Nucleus ambiguus), or efferent connections (mesencephalic nucleus of V, Locus coeruleus, Griseum Centrale and inferior and superior colliculi) and those having both types of connections (Nucleus tractus solitarii (N.F.S.), Dorsal vagal nucleus, nucleus intercalatus, hypoglossal nucleus).
Middle radial cells have somata scattered throughout the stratum Griseum Centrale and stratum fibrosum et griseum superficiale and do not contact each other.
The p-neurons also have a basal dendritic shaft and a descending axon, both of which branch out horizontally at the stratum Griseum Centrale (SGC).
The infrared cell group is found in layer 7 (a and b; stratum Griseum Centrale) throughout the optic tectum.
The present results indicate that the NRD, particularly is rostral part, receives direct projections arising from: (1) locus coeruleus complex (locus coeruleus, locus coerulus alpha, and locus subcoeruleus); (2) parabrachial nuclei (nucleus parabrachialis lateralis and medialis); (3) nucleus laterodorsalis tegmenti; (4) Griseum Centrale pontis, particularly the caudal part of the nucleus incertus; (5) substantia nigra; (6) lateral habenular nucleus; (7) hypothalamic areas, particularly dorsal and lateral hypothalamic areas; (8) preoptic areas; (9) anarea dorso-lateral to the inferior olivary complex and medial to the lateral reticular nucleus; and (10) raphe nuclei; particularly nucleus linearis intermedius, centralis superior, pontis and magnus.
Cells which lie at various depths in the stratum Griseum Centrale (SGC) of the tectum project upon distinct subdivisions of nucleus rotundus.
Telencephalic efferents teminate ipsilaterally in the middle level of the tectum's stratum Griseum Centrale; in Holocentrus there is also a small projection to the stratum opticum.
Contralateral projections were traced to the lateral geniculate nucleus, nucleus pretectalis, accessory optic nucleus, nucleus corticalis, nucleus opticus hypothalamicus and the superficial layers of the optic tectum (strata opticum, fibrosum and griseum superficiale, and the cellular zone of Griseum Centrale).
Optic tract axons cross completely in the optic chiasma and are distributed to the hypothalamus (nucleus opticus hypothalamicus pars magnocellularis), the thalamo-pretectal region (11 distinct primary optic centers), and the tectum opticum (stratum fibrosum et griseum superficiale, stratum Griseum Centrale and stratum album centrale).
In the deeper layers (stratum Griseum Centrale, stratum album centrale) unimodal and bimodal units were encountered.
A lesion which involved both the retinal-recipient layers and stratum Griseum Centrale resulted in degeneration in only one additional structure, nucleus rotundus.
It was impossible to identify the main target zone of retinotectal projection (the stratum fibrosum et griseum superficiale) or the central cellular layer (the stratum Griseum Centrale) in the reimplants.
Distinct layer was lacking in the medial tectum with a conspicuously absent large cell layer in the stratum Griseum Centrale (sgc).
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