Medial Nucleus Of Pulvinar

anterodorsal, anteroprincipal, laterodorsal, fasciculosus, mediodorsal, central lateral, central medial, cucullar, and paracentral nuclei, medial nucleus of the pulvinar) underwent neurodegeneration.  

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.  

Previous studies in the macaque monkey have identified a thalamic nucleus, the posterior portion of the ventral medial nucleus (VMpo), as a dedicated lamina I spinothalamocortical relay for pain and temperature sensation.  

Fast Blue injections in the MT labelled neurons largely in the medial nucleus of the inferior pulvinar. A few labelled neurons were found in the adjoining central medial nucleus of the inferior pulvinar, as well as in the lateral pulvinar and the dorsal lateral geniculate nucleus. The results indicate that the medial nucleus of the inferior pulvinar, the major projection zone to the MT, does not receive a significant input from the superior colliculus..  

Moderate or low concentrations of phenyletanolamine-N-methyltransferase-immunopositive fibres are present in the paratenial nucleus, and all parts of the central nucleus, nucleus reuniens, central medial nucleus, centromedian nucleus, medial geniculate body and medial pulvinar nucleus, while only scattered immunoreactive axons are found in other thalamic nuclei.  

In all three primates, we identified the posterior nucleus (PIp) and the medial nucleus (PIm) of previous reports, and divided the previously recognized central nucleus (PIc) into two subdivisions, medial (PIcM) and lateral (PIcL).  

The medial nucleus of the pulvinar complex (PM) has widespread connections with association cortex.  

ITC and ITR receive afferents from the locus coeruleus, dorsal raphe, nucleus annularis, central superior nucleus, pontine reticular formation, lateral hypothalamus, paracentral nucleus, and central medial nucleus; send efferents to the superior colliculus, reticular nucleus, and striatum; and have both afferent and efferent connections with the pretectum, pulvinar, claustrum, amygdala, and basal nucleus of Meynert.  

The CO-weak compartment, containing only calbindin cells, forms isolated zones throughout VPL and expands as a cap covering the posterior surface of the ventral posterior medial nucleus (VPM).  

HRP injections into the Ts resulted in labeled cells in the posterodorsal division of the principal medial geniculate complex (GMpd), the suprageniculate and limitans nuclei, and the medial part of the medial nucleus of the pulvinar complex.  

The connections of Pa with the primary somatosensory cortex, area 3b, the location of Pa relative to the ventroposterior nucleus, and the high degree of topographic order in the connections of Pa with the postcentral cortex suggest that Pa is an integral part of the somatosensory thalamus in monkeys and is homologous to the medial nucleus of the posterior group (Pom) in other mammals.  

Lesions of the medial nucleus of the globus pallidus appear as hyperechoic foci that abut on the anterior surface of genu just above the peduncle and that have a narrow convex caudal margin. Lesions of the lateral nucleus of globus pallidus abut on the genu distant from the peduncle, spare the medial nucleus adjacent to the peduncle, and have a broad caudal border.  

The location of the thalamic representations of the head, face, and intraoral structures that project to S2 may be in the ventroposterior medial nucleus (VPM).  

It appears that the medial nucleus of the pulvinar sends projection fibres to the posterior cingulate gyrus (area 23), the retrosplenial area, and the posterior parahippocampal gyrus (areas TH and TF). The medial nucleus of the pulvinar was already known to be connected with the prefrontal cortex and with the inferior parietal lobule.  

Tritiated amino acid injections limited to the insula revealed autoradiographic label in the principal and parvicellular components of the ventroposterior medial nucleus, the ventroposterior inferior nucleus, the oral and medial pulvinar nuclei, the nucleus reuniens, the parvicellular and magnocellular components of the medial dorsal nucleus, the centromedian-parafasicularis nuclei, and the reticular nucleus.  

Following injections of HPR into the medial prefrontal cortex and the ventral portion of the lateral prefrontal cortex, a large number of labeled cells were found in the dorsomedial nucleus of the ipsilateral thalamus, particularly its medial and dorsal parts. Injections of HRP into the dorsal part of the lateral prefrontal cortex, including the medial bank of the presylvian sulcus, resulted in heavy labeling of cells particularly in the lateral and ventral parts of the ipsilateral dorsomedial nucleus. Some labeled cells were found in the ventral medial nucleus, and a lesser number in the submedial nucleus.  

These HRP-positive cells were in the dorsal and lateral hypothalamic area, dorsal medial nucleus and in the lateral mammillary nucleus.  

We have divided the inferior pulvinar into a large central nucleus, IPc, with topologically organized input from Area 17; a smaller medial nucleus, IPm, with a second pattern of input from Area 17; and a dorso-posterior nucleus, IPp, without input from striate cortex.  

The auditory fields are bounded on three sides by the projection field of the medial nucleus of the pulvinar which also extends into the upper end of the lateral sulcus to bound the fields receiving fibers from the posterior nucleus.  

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