Several nuclei within the posterior thalamus were targets of STT neurons: the posterior nucleus, suprageniculate nucleus, magnocellular part of the medial geniculate nucleus, and limitans nucleus. 
At subcortical levels, we observed a similar correspondence of retrogradely labeled cells and anterogradely labeled axons and terminals in visual (posterior limitans thalamic nucleus) and multisensory thalamic nuclei (dorsal and medial division of the medial geniculate body, suprageniculate nucleus, posterior thalamic cell group, zona incerta), and in the multisensory nucleus of the brachium of the inferior colliculus.
The postnatal development of the corticothalamic projection from the lateral suprasylvian cortex (LS) to the lateral medialis-suprageniculate nucleus (LM-Sg) of the cat thalamus was assessed by means of the anterograde tracer biocytin.
The spatial and temporal visual sensitivity to drifting sinusoidal gratings was studied in 105 neurons of the suprageniculate nucleus of the feline thalamus. Most suprageniculate nucleus cells were strongly sensitive to the direction of drifting gratings. The suprageniculate nucleus units had a clear preference for very low spatial frequencies with a mean of 0.05 cycle/deg. The suprageniculate nucleus units were extremely narrowly tuned, to spatial frequencies with a mean spatial bandwidth of 1.07 octaves. These results demonstrate that the neurons in the suprageniculate nucleus display particular spatial and temporal characteristics. The spatial and temporal tuning properties of the suprageniculate nucleus neurons are very similar to those of the superior colliculus and the anterior ectosylvian cortex, structures that provide the main visual afferentation toward the suprageniculate nucleus.
This study describes the visual information coding ability of single neurons in the suprageniculate nucleus (Sg), and provides new data concerning the visual information flow in the suprageniculate/anterior ectosylvian pathways of the feline brain.
In addition, this study described the dorsal claustrum as a novel telencephalic target for the suprageniculate nucleus in mammals. With the exception of the isocortical connections, the mouse suprageniculate nucleus shares a number of afferent and efferent connections with the sauropsidian nucleus rotundus.
We examined efferent connections of the cortical auditory field that receives thalamic afferents specifically from the suprageniculate nucleus (SG) and the dorsal division (MGD) of the medial geniculate body (MG) in the rat [ Neuroscience 117 (2003) 1003].
A dense corticothalamic projection from A1 was found in the ventral (vMGB) and dorsal (dMGB) divisions of the medial geniculate body and, to a lesser extent, in the medial division (mMGB), the posterior thalamic nucleus (PO) and the suprageniculate nucleus.
The pedunculopontine tegmental nucleus (PPT) projects its cholinergic fibers to both the lateralis medialis-suprageniculate nucleus (LM-Sg) and the superior colliculus (SC).
In contrast to exclusively selective projections to cortical area Te1 from the ventral division (MGV) of the MG, diffuse and selective terminations were observed in the projections from the dorsal (MGD) and medial divisions (MGM) of the MG and the suprageniculate nucleus (SG).
The ICXv projects to the suprageniculate nucleus (Sg) of the medial geniculate body.
In rats, ErbB4 expression was observed in the habenular nuclei, the paraventricular nucleus, intermediodorsal nucleus, the central medial thalamic nucleus, the posterior nucleus, the parafascicular nucleus, the subparafascicular nucleus, the suprageniculate nucleus, the posterior limitans nucleus, the medial part of the medial geniculate nucleus, the peripeduncular nucleus, the posterior intralaminar nucleus, the lateral subparafascicular nucleus, the lateral posterior nucleus, and all ventral thalamic nuclei.
This study was designed to investigate the number and form of cerebellar fastigial neurons projecting to the suprageniculate nucleus(Sg) by using retrograde axonal transport of wheat germ agglutinin-horseradish peroxidase(WGA-HRP).
We also demonstrated by the same method that a complex of thalamic nuclei, comprising the medial part of the medial geniculate nucleus, the posterior intralaminar nucleus, and the suprageniculate nucleus, is involved in fear-conditioning, but not in LI.
the suprageniculate nucleus (SG), the posterior intralaminar nucleus (PIN), the medial division of the medial geniculate nucleus (MGm), and the peripeduncular nucleus (PP), are regarded as important extralemniscal relay nuclei for sensory stimuli and as an important link for the direct transmission of sensory stimuli to the amygdala.
These nuclei, which include the suprageniculate nucleus (SG), the posterior intralaminar nucleus (PIN), the peripeduncular nucleus (PP) and the medial division of the medial geniculate body (MGm), project to both cortex and amygdala, but target areas and the extent of the projection of individual nuclei are not known yet.
Anesthetized cats were injected with 2% fast blue into the suprageniculate nucleus and with 0.5% nuclear yellow into the superior colliculus.
It is well documented that these projections originate in the medial division (MGm) of the medial geniculate nucleus (MGN), the posterior intralaminar nucleus (PIN), and the suprageniculate nucleus (Sg).
the suprageniculate nucleus, the medial division of the medial geniculate nucleus, the posterior intralaminar nucleus and the peripeduncular nucleus) which relay sensory information to the amygdala are thought to receive convergent input from multiple sites. Injections of Miniruby into the suprageniculate nucleus labelled predominantly neurons in the stratum opticum of the superior colliculus, whereas injections into the medial division of the medial geniculate body, the posterior intralaminar nucleus and the peripeduncular nucleus labelled predominantly neurons in the deep layers of the superior colliculus. After injections into the suprageniculate nucleus, only neurons in layer 2 were found.
the suprageniculate nucleus, the medial division of the medial geniculate body, the posterior intralaminar nucleus, and the peripeduncular nucleus. Tecto-thalamic axons originating from superficial collicular layers were found predominantly in the suprageniculate nucleus, whereas axons from deep collicular layers were detected in equal density in all thalamic nuclei surrounding the medial geniculate body.
Injections of tracer into the DZ retrogradely labeled cells mainly in the lateral division of posterior complex (Po) and in the dorsal division (MGd) of the medial geniculate body (MGB); fewer labeled cells were found in the ventral (MGv) and medial (MGm) divisions of the MGB and in the suprageniculate nucleus.
Neurons double-labeled with both tracers were found mainly in the posterior intralaminar nucleus and suprageniculate nucleus, and to a lesser extent in the subparafascicular nucleus and medial division of the medial geniculate nucleus.
Response properties of 252 single-units to visual, auditory, somatosensory and noxious stimulation were recorded by means of extracellular microelectrodes in the suprageniculate nucleus of anaesthetized, immobilized cats. The physiological properties of suprageniculate nucleus cells strongly resemble the sensory properties of cells found along the ventral bank of the anterior ectosylvian sulcus and the deeper layers of the superior colliculus.
In addition, there was a widespread, homogeneously distributed collicular input to the lateralis posterior-pulvinar complex and a distinct tectal projection to the suprageniculate nucleus.
Physiological properties of single units were investigated in the suprageniculate nucleus (SG) and in the cerebral cortex along the anterior ectosylvian sulcus (AES), including the insular cortex. The physiological properties of the cells in the suprageniculate nucleus and in the AES/insular cortex exhibited striking similarities in a series of aspects: (a) The frequencies of occurrence of uni-, bi- and trimodal cells were similar.
The suprageniculate nucleus (SG) was considered to be the origin of the rat direct pathway to the frontal cortex. The present results suggest that projections from the suprageniculate nucleus to the frontal cortex and the temporal cortex consist of separate neuronal groups in the rat MGB and SG.
Retrograde labeling of the polymodal zones indicated that they receive parallel thalamocortical projections primarily from non-specific auditory and visual thalamic nuclei including the medial and dorsal divisions of the medial geniculate nucleus (MGm and MGd), the suprageniculate nucleus (SGN), and the lateral posterior nucleus (LP).
Pre- or posttraining lesions of the entire auditory thalamus including the ventral, dorsal, and medial divisions of the medial geniculate body, the posterior intralaminar nucleus, and the suprageniculate nucleus, completely blocked fear-potentiated startle to the auditory CS, but had no effect on fear-potentiated startle to the visual CS.
A wheat germ-agglutinated horseradish peroxidase (WGA-HRP) tracing technique was used to label the cell bodies of neurons in the superior colliculus that send projections into the visually sensitive region of the suprageniculate nucleus (Sg) in the feline thalamus.
Following WGA-HRP injection into the right suprageniculate nucleus of the cat brain, retrogradely-labeled neurons were found not only in the ipsilateral, but also in the contralateral superior colliculi. When a different kind of fluorescent tracer was injected into each suprageniculate nucleus (Fast blue and Nuclear yellow), double-labeled neurons were observed in the rostral and middle portions of both superior colliculi.
A third input was to the suprageniculate nucleus, which received strong, topographically arranged projections.
These neurons are medium-sized except in the suprageniculate nucleus, where many cells are larger. suprageniculate nucleus neurons have radiating dendritic fields that project spherically; they have fewer branches than dorsal nucleus neurons. The posterior limitans nucleus is dorsomedial to the suprageniculate nucleus; it has small neurons with long, sparsely branched dendrites.
The suprageniculate nucleus is prominent and has many large radiate neurons. The suprageniculate nucleus has thick myelinated axons, while the fibers in the superficial and dorsal nuclei are much thinner.
The thalamic areas focused on were the medial division of the medial geniculate body (MGm), the suprageniculate nucleus (SG), and the posterior intralaminar nucleus (PIN), thalamic areas that receive inputs from both the inferior colliculus and the spinal cord and that project to the lateral nucleus of the amygdala (AL).
The emphasis was on the medial division of the medial geniculate body (MGm), the suprageniculate nucleus (SG), and the posterior intralaminar nucleus (PIN), thalamic areas that receive inputs from the inferior colliculus and project to the lateral nucleus of the amygdala (AL).
Within the medial geniculate body (MGB), stained cell bodies were observed in the dorsal part of the suprageniculate nucleus and in the basal part of the medial division of the MGB.
Axonal transport of WGA-HRP injected into (1) the suprageniculate nucleus or (2) the fastigial nucleus, was investigated. Retrogradely labeled neurons were found in the caudal part of the bilateral fastigial nucleus following injection 1, and anterograde labeled axon terminals were observed in the bilateral suprageniculate nucleus following injection 2. These results suggest that some neurons in the fastigial nucleus send their axons to the suprageniculate nucleus..
Contralaterally, only the nuclei that project to the amygdala (the medial division of the medial geniculate body, the posterior intralaminar nucleus, and the suprageniculate nucleus) were selectively destroyed, leaving much of the thalamo-cortico-amygdala projection intact.
Connections with the auditory cortex and suprageniculate nucleus are not evident.
Injection of WGA-HRP into the lateral nucleus of the amygdala produced retrograde axonal transport to cell bodies in areas of the acoustic thalamus: the medial division of the medial geniculate body, the suprageniculate nucleus, and the posterior intralaminar nucleus.
In the auditory thalamus, nearly every cell in the medial geniculate body was cabp(+), but those in the suprageniculate nucleus and in the posterior group did not stain.
The cortex of the upper bank of the STS-multimodal areas TPO and PGa-projects to four major thalamic targets: the pulvinar complex, the mediodorsal nucleus, the limitans-suprageniculate nucleus, as well as intralaminar nuclei.
Frontal cortical projections from the rat suprageniculate nucleus (SG) were investigated by an anterograde tracing using Phaseolus vulgaris-leucoagglutinin (PHA-L).
The suprageniculate nucleus and the lateral and medial divisions of the posterior nuclear group were also labelled in most experiments.
The suprageniculate nucleus includes neurons with large somata and long, sparsely branched and dorsoventrally oriented dendrites orthagonal to corticothalamic axons, as well as smaller neurons and classical stellate cells.(ABSTRACT TRUNCATED AT 400 WORDS).
Injections in AL and AST produced retrograde transport to neurons in the medial division of the medial geniculate body (MGM), PIN, suprageniculate nucleus (SG) and, to a lesser extent, the lateral posterior nucleus (LP).
From these areas, fragment C exhibited retrograde transneuronal transport, strongly and reliably labeling regions that project to retinorecipient areas, including layers V and VI of visual cortex, the parabigeminal nucleus, the suprageniculate nucleus, and the reticular thalamus.
Following injection of WGA-HRP into the AESo, both anterogradely-labeled terminals and retrogradely-labeled cells were found with the highest concentration in the suprageniculate nucleus and the medial zone of the lateroposterior nucleus of the thalamus.
The common reciprocal connections were found in the ventral anterior-ventral lateral complex, principal ventromedial nucleus, rostral intralaminar nuclei, centromedian-parafascicular complex, lateral posterior nucleus, and suprageniculate nucleus.
The only thalamic injections that produced retrograde transport to cells in auditory nuclei caudal to the inferior colliculus were those that included the suprageniculate nucleus. The pathway revealed by these studies is almost identical to the "central acoustic tract" in which fibers course medial to the lateral lemniscus and bypass the inferior colliculus to reach the deep superior colliculus and the suprageniculate nucleus..
The results support several conclusions: (1) high to low frequencies are represented in a dorsocaudal to ventrorostral sequence in A-I, (2) intrinsic connections in A-I are more pronounced along isofrequency contours, (3) the pattern of connections between A-I and adjoining cortex suggests that this surrounding auditory cortex contains at least two tonotopically organized fields and possibly one or more additional auditory fields, (4) callosal connections of A-I are largely between parts of A-I matched for frequency representation, (5) thalamic connections of A-I include topographic connections with the ventral division of the medial geniculate complex (MGv) and more diffuse connections with the medial (MGm) and dorsal (MGd) divisions of the medial geniculate complex and the suprageniculate nucleus (Sg), and (6) A-I projects bilaterally to the dorsal cortex of the inferior colliculus..
The dorsal division consists of the dorsal nuclei, including the suprageniculate nucleus and the caudal part of the lateral posterior nucleus, the marginal zone, and the posterior limitans nucleus.
When the injection site was relatively restricted to the sulcal walls and fundus of the rostral AES (i.e., the SIV cortex), heavy ipsilateral thalamic label was observed in the medial subdivision of the posterior group, in the suprageniculate nucleus, and in the external medullary lamina.
An intermediate strip, to which we refer as the auditory belt, is innervated by axons from nontonotopic divisions of the medial geniculate body (MGds, MGvl, MGm, and MGd), from the lateral division of the posterior group (Pol), and from the posterior suprageniculate nucleus (SGp).
Nevertheless, all three types of opiate receptors were found in the ventral and dorsal subdivisions of the lateral geniculate (LGN), the pulvinar complex, and the suprageniculate nucleus.
Following injections in the inferior colliculus, terminal labeling was present in ventral, medial, and dorsal divisions of the medial genicuate body (MGB) and in adjacent areas of the posterior thalamus, including the posterior limitans nucleus, the posterior intralaminar nucleus, the marginal zone, the peripeduncular region, the lateral or parvicellular part of the subparafascicular nucleus, and a region intercalated between the posterior limitans nucleus and the suprageniculate nucleus.
The neuropil staining appears particularly dense in the nuclei parataenialis, periventricularis, centralis medialis, reuniens, rhomboideus, habenularis lateralis, centrum medianum, parafascicularis, subparafascicularis, submedius, dorsal and ventral parts of the lateral geniculate body, the dorsal part of the medial geniculate body, the posterior complex, suprageniculate nucleus, pulvinar and parts of the lateral posterior nucleus.
An area in the frontal cortex receives a direct projection from a division of the auditory thalamus, the suprageniculate nucleus, which in turn receives input from the anterolateral peri-olivary nucleus, an auditory center in the medulla.
Prefrontal projections to the reticular nucleus, medial pulvinar, suprageniculate nucleus, and limitans nucleus appear to be exclusively ipsilateral.
After HRP injection into layer I of the primary auditory cortex (AI), HRP-labeled neuronal cell bodies were distributed mainly in the medial, dorsal, and ventrolateral divisions of the medial geniculate nucleus (MGN) and suprageniculate nucleus (Sg), and additionally in the lateral and medial divisions of the posterior group of the thalamus (Pol and Pom), lateroposterior thalamic nucleus (Lp), and nucleus of the brachium of the inferior colliculus (BIN).
In the pars ovoidea, the rostral half of the pars magnocellularis (PM) and the suprageniculate nucleus, CF sequences and quantitative evaluations of the tonotopicity indicated the presence of some degree of tonotopic organization which was lower than in PL.
It was shown that visual information comes to the caudate nucleus not only through the well-known polysynaptic pathways from the cerebral cortex, but also through both oligosynaptic (via pulvinar, lateroposterior nucleus, suprageniculate nucleus and nucleus limitans of the thalamus) and disynaptic pathways (via medial and lateral terminal nuclei of the accessory optic tract, pulvinar, pretectum, intermediate superior colliculus layer, supraoptic nucleus) some of which were found for the first time. Direct retinal inputs to the suprageniculate nucleus were found.
The SII receives a few fibers from the medial geniculate nucleus, particularly its magnocellular and dorsal principal parts, and from the suprageniculate nucleus. The fourth somesthetic area (SIV), located in the dorsal bank of the anterior ectosylvian sulcus, receives fibers mainly from the dorsal principal and magnocellular parts of the medial geniculate nucleus, and from the suprageniculate nucleus.
A few labeled cells were also located in the suprageniculate nucleus.
Small iontophoretic ejections of horseradish peroxidase (HRP) were made from recording-multibarrel micropipette assemblies in areas of the cat's suprageniculate nucleus (SGn) that contained visually responsive neurones.
The suprageniculate nucleus (Sg) of the cat was observed electron microscopically after wheat germ agglutinin-horseradish peroxidase (WGA-HRP) injection into the anterior ectosylvian visual cortical area (AEV) and superior colliculus (SC).
The suprageniculate nucleus of the posterior thalamus is a source of non-intralaminar thalamic nucleus which projects selectively to the medial and intermediate regions of the caudate nucleus in cats..
The middle part of the posterior ectosylvian gyrus receives afferents from the posterior nucleus of the thalamus, the suprageniculate nucleus and the pulvinar, while the posterior part of the posterior ectosylvian gyrus together with the posteriormost part of the posterior sylvian gyrus receive afferents from the pulvinar.
The suprageniculate nucleus, located within the body of the MG just dorsal to the medial division, was also identified. Injections in the caudate-putamen or amygdala retrogradely labeled the medial division of the MG and the suprageniculate nucleus, as well as several adjacent areas of the posterior thalamus surrounding the MG. These data demonstrate that the medial division of MG, the suprageniculate nucleus, and immediately adjacent areas of the posterior thalamus provide a direct linkage between auditory neurons in the inferior colliculus and subcortical areas of the forebrain and thereby support the view that thalamic sensory nuclei relay afferent signals to subcortical as well as cortical areas..
In addition to its input from the Pul.m., area 7a is also reciprocally connected with the magnocellular division of the nucleus ventralis anterior, with the nuclei which abut upon the medullary capsule of the laterodorsal nucleus, and with the suprageniculate nucleus and the nucleus limitans.
Reciprocally bilateral connections between the superior colliculus and the suprageniculate nucleus have been studied in the rat, using the anterograde and retrograde transport techniques of HRP. In those cases where the HRP deposit was restricted to the superficial layers of the colliculus, anterogradely labeled fibers and retrogradely labeled neurons were observed in the ipsilateral suprageniculate nucleus. However, upon HRP injection extended into the intermediate layers of the colliculus, the number of labeled fibers and neurons was not only increased ipsilaterally but were also observed in the contralateral suprageniculate nucleus. These results show that the suprageniculate nucleus and the superior colliculus are connected reciprocally and bilaterally, with an ipsilateral dominance..
The other thalamic projections to the Put arise mainly from the suprageniculate nucleus (Sg), magnocellular division of the medial geniculate nucleus (MGm), caudomedial part of the lateroposterior nucleus (LP) and ventrolateral part of the ventromedial nucleus (VM).
Area 36 receives many fibers from the ventrolateral part of the medial pulvinar nucleus and the suprageniculate nucleus, a lesser number from the other parts of the medial pulvinar nucleus, and some fibers from the medial geniculate nucleus, particularly its dorsal principal part..
Projections from the posterior thalamic regions to the striatum were studied in the cat by the anterograde tracing method after injecting wheat germ agglutinin-horseradish peroxidase conjugate (WGA-HRP) into the caudalmost regions of the lateroposterior thalamic nucleus (caudal LP), suprageniculate nucleus (Sg) and magnocellular division of the medial geniculate nucleus (MGm).
Rather essential are projections of the "posterior group nuclei", those of the suprageniculate nucleus, of some parts of the ventral thalamus (subparafascicular nucleus, marginal and peripeduncular nuclei) and parabrachial nucleus.
The major differences in distribution patterns were as follows: Injections of HRP into the lateral or ventrolateral portions of the ventroanterior and ventrolateral nuclear complex of the thalamus (VA-VL) produced retrogradely labeled neurons consistently in area 4 gamma (lateral part of the anterior and posterior sigmoid gyri, lateral sigmoid gyrus and the lateral fundus of the cruciate sulcus), the medial division of posterior thalamic group (POm), suprageniculate nucleus (SG) and anterior pretectal nucleus ipsilaterally, and in the nucleus Z of the vestibular nuclear complex bilaterally.
The most prominent loci of thalamic labeling were the suprageniculate nucleus and parts of the posterolateral nucleus.
Visual response properties were studied in 83 single units recorded in the cat suprageniculate nucleus (Sg).
HRP injected into layer I of the primary auditory cortex (AI) in the cat labeled neuronal cell bodies ipsilaterally in the medial, dorsal and ventrolateral divisions of the medial geniculate nucleus (MGN), suprageniculate nucleus, and nucleus of the brachium of the inferior colliculus.
The substantia nigra (SN) of the cat was shown, by the anterograde and retrograde horseradish peroxidase methods, to contain neurons which send their axons to the caudomedial portions of the suprageniculate nucleus and/or lateroposterior nucleus of the thalamus; these neurons were located in the restricted region in the lateral part of the SN, which corresponds to the pars lateralis of the SN..
In contrast, the posterior insula is more extensively connected with the ventroposterior inferior nucleus, the oral and medial pulvinar nuclei, and the suprageniculate nucleus.
Visually responsive neurones of the cat's suprageniculate nucleus were categorized according to their responses to a variety of different types of light stimuli.
In the suprageniculate nucleus, the principal neurons are stellate cells with large perikarya and numerous and extensive dendrites covered with appendages.
Auditory responses in the suprageniculate nucleus were poorly defined and many units did not respond to tonal stimuli; following HRP injections no filled cells were found in the inferior colliculus, but labeled cells were found in the deeper layers of the superior colliculus and in the interstitial nucleus of the brachium of the inferior colliculus.
It receives scarcely any fibers from the suprageniculate nucleus.
Consistent numbers of labeled neurons were also identified in the lateral medial subdivision of the lateral posterior-pulvinar complex, suprageniculate nucleus, posterior thalamic nuclear group and magnocellular division of the medial geniculate nucleus.
It was evident that among the entire scope of its inputs, the FEF received a prominent afferent projection from the nucleus of the optic tract (NOT, nucleus limitans) and the suprageniculate nucleus, and projected to a medial subdivision of NOT, sublentiform nucleus, nucleus of the pretectal area, nucleus of the posterior commissure, and the rostral periaqueductal gray.
These particular non-monotonic "lockers" were more commonly-found in the posterior part of the pars lateralis and in the suprageniculate nucleus.
In addition, PO contains three distinct nuclei: 1) the magnocellular (MC) portion of the medial geniculate nucleus; 2) the nucleus limitans (Lim); and 3) the suprageniculate nucleus (SG).
The suprageniculate nucleus contains large, loosely-packed cells and receives projections from the deep layers of the superior colliculus and from the midbrain tegmentum.
These indicated that although only PM of the pulvinar subnuclei projected to these regions, three other caudal thalamic structures, i.e., medial dorsal nucleus, nucleus limitans and suprageniculate nucleus also projected to these regions raising some questions about the identity of the densocellular part of the medial dorsal nucleus which has also been considered to be part of pulvinar.
Following lesions of the deep layers of the superior colliculus, degenerated axonal endings were found in the central gray, magnocellular medial geniculate nucleus, suprageniculate nucleus, limitans nucleus, lateral posterior nucleus, medial and oral pulvinar, nucleus of the accessory optic tract, zona incerta, subdivisions of the ventral lateral and ventral posterior lateral nuclei, ventral posterior inferior nucleus, denosocellular and multiform dorsomedial nuclei, all intralaminar nuclei, inferior colliculus, parabigeminal nucleus, olivary nucleus, reunions nucleus, Forel's Field H and an undefined midbrain nucleus.
Single unit activity was recorded in the medial reticular formation of the brainstem, in the medial thalamus and, more laterally, among the posterior group nuclei and the suprageniculate nucleus.
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