In this review, we present evidence that a subset of medial nuclei in the inferior pulvinar function predominantly as a subcortical component of the dorsal stream while the most lateral nucleus of the inferior pulvinar and the adjoining ventrolateral nucleus of the lateral pulvinar are more devoted to the ventral stream of cortical processing. 
Area PE sends a major projection terminating with small endings to the thalamic lateral posterior nucleus (LP), ventral posterior lateral nucleus (VPL), medial pulvinar (PuM) and, but fewer, to ventral lateral posterior nucleus, dorsal division (VLpd), central lateral nucleus (CL) and center median nucleus (CM), whereas giant endings formed restricted terminal fields in LP, VPL and PuM.
During our pathoanatomical study we disclosed (i) a consistent degeneration of the ventral anterior, ventral lateral and reticular thalamic nuclei; (ii) a degeneration of the ventral posterior lateral nucleus and inferior and lateral subnuclei of the pulvinar in the majority of these SCA3 patients; and (iii) a degeneration of the ventral posterior medial and lateral posterior thalamic nuclei, the lateral geniculate body and some of the limbic thalamic nuclei in some of them.
Projections to area 1 were highly convergent from several thalamic nuclei including the ventral lateral nucleus (VL), anterior pulvinar (PA), VPl, and the superior division of the ventral posterior nucleus (VPs). In cortex immediately caudal to area 1, what we term area 5, thalamocortical connections were also highly convergent and predominantly from nuclei of the thalamus associated with motor, visual, or somatic processing such as VL, the medial pulvinar (PM), and PA, respectively; with moderate projections from VP, central lateral nucleus (CL), lateral posterior nucleus (LP), and VPs.
Very high or high histaminergic fibre densities were observed in the midline nuclear region and other nuclei next to the third ventricle, ventroposterior lateral nucleus and medial geniculate nucleus.
Surprisingly, area 3a receives the majority of its input from thalamic nuclei associated with the motor system, posterior division of the ventral lateral nucleus of the thalamus (VL), the mediodorsal nucleus (MD), and intralaminar nuclei including the central lateral nucleus (CL) and the centre median nucleus (CM). The indirect input from the cerebellum and basal ganglia via the ventral lateral nucleus of the thalamus supports its role in proprioception.
There were sparser inputs to the central lateral nucleus of the inferior pulvinar, locations in the lateral and medial pulvinar, and the dorsal lateral geniculate nucleus.
The hyperintense area was confined to the dorsomedial or anterior and dorsomedial nuclei of the thalamus in nine of the 14 patients; it extended from the dorsomedial or anterior and dorsomedial nuclei to the ventral lateral nucleus or pulvinar in the remaining five patients.
The thalamic posterior lateral nucleus was shown to exert phasic and tonic effects on the function of sensomotor cortex: the former in the form of pulvinar-cortical responses, and the latter in the form of foci of increased or decreased excitability. The findings suggest an inhibitory tonic effect of the sensomotor cortex on neuronal network of the posterior lateral nucleus..
In the intact animals, the labeled neurons were distributed sparsely in the central lateral nucleus and in the lateral posterior and pulvinar nuclear complex.
Injections of an anterograde axonal tracer, phaseolus vulgaris leucoagglutinin (PHA-L), in area 17 resulted in labeling of small boutons in the dorsal lateral geniculate, perigeniculate, and thalamic reticular nuclei and in labeling of large boutons in the lateral nucleus of lateral posterior-pulvinar, ventral lateral geniculate, and pulvinar nuclei.
Injections in ITC label sparse projections to the lateral nucleus of the amygdala, in contrast to injections in ITR that label strong projections to the lateral and basal nuclei of the amygdala.
The ventral posterior lateral nucleus (VPL) of the monkey thalamus was investigated by histochemical staining for cytochrome oxidase (CO) activity and by immunocytochemical staining for the calcium-binding proteins parvalbumin and 28 kDa calbindin.
In addition to the pulvinar nucleus, Pbg projections were found to terminate in layers 4 and 5 of the dorsal lateral geniculate nucleus and the central lateral nucleus.
Thus, in the SPL, the ventral posterolateral nucleus, pars oralis (VPLo), ventral lateral nucleus, pars oralis (VLo), and ventral lateral nucleus, pars medialis (VLm) project to rostral regions, whereas the PM and limbic nuclei, anteroventral (AV), and anteromedial (AM), project to area PGm on the medial convexity of the SPL.
In these animals, label was located mainly in suprageniculate and pulvinar oralis, caudal and oral divisions of ventral posterior lateral nucleus, the lateral half of ventral posterior inferior nucleus, and zona incerta, while in the medial thalamus label was primarily in two distinct bands in medial dorsal nucleus and in the posterior dorsal portion of central lateral nucleus.
Partial representations of the visual field were also evident in the geniculate wing, subdivisions of the lateral posterior shell, the inferior division of the posterior nuclear group, the suprageniculate nucleus, and the central lateral nucleus.
Projections to visual cortex from the dorsal lateral geniculate nucleus and lateral-posterior/pulvinar complex exist by E46, and those from the contralateral hemisphere, claustrum, putamen, and central lateral nucleus of the thalamus are present by E54-E56.
In the amygdala, labeled cells were observed principally in the lateral nucleus, the accessory basal nucleus, the deep or paralaminar portion of the basal nucleus, and the periamygdaloid cortex.
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 lesion was located in the dorsal aspect of the lateral nucleus, but it extended into the pulvinar, including the anterior superior lateral aspect which has been implicated in language by previous studies.
S2 was shown to receive its major thalamic input from the ventroposterior inferior thalamic nucleus (VPI) and not, as previously reported, from the caudal division of the ventroposterior lateral nucleus (VPLc). Larger injections, which included the representations of more body parts, led to heavy label in VPI, with scattered label in VPLc, the central lateral nucleus (CL), and the posterior nucleus (Po).
Injections restricted to V1 revealed a dense projection from the dorsal lateral geniculate nucleus as well as projections from the pulvinar, the posterior thalamic nucleus, and the ventral lateral nucleus. Injections restricted to V2 revealed projections from the pulvinar, the ventral lateral nucleus, and the posterior thalamic nucleus, but only a slight projection from the dorsal lateral geniculate nucleus.
This case also shows that thalamic aphasia and anterograde amnesia may be related to a paramedian lesion of the thalamus, with special reference to involvement of the dorsomedial nucleus, in the absence of lesion of the pulvinar and mamillo-thalamic tract and of conspicuous involvement of the ventral lateral nucleus.
In contrast, asymmetry, more pronounced on the left side, exists in the posterior lateral nucleus.
A prominent projection to area 5a arises from the posterior (Po) and ventral lateral (VL) complexes; less substantial projections originate in the ventral anterior nucleus (VA), the lateral intermediate complex (LI), and the central lateral nucleus (CL).
Labeled terminals in the subcortex were distributed in the caudate nucleus, the claustrum, the putamen, the anterior ventral nucleus, the intralaminar nuclei, the caudal division of the intermediate lateral nucleus, the lateralis posterior-pulvinar complex, the parvocellular C laminae of the dorsal lateral geniculate nucleus and the ventral lateral geniculate nucleus.
Projections from MT to the pons terminate rostrally in the dorsolateral nucleus, the lateral nucleus, and the dorsolateral portion of the peduncular nucleus.(ABSTRACT TRUNCATED AT 400 WORDS).
Area 5 receives a large number of fibers from the posterior lateral nucleus, and a few fibers from the dorsal lateral nucleus. It receives many fibers from the lateral pulvinar nucleus, and a few fibers from the dorsal lateral nuclei, the dorsolateral part of the posterior lateral nucleus and the lateral central and paracentral nucleus. However, the lateral bank receives more fibers from the posterior lateral nucleus, and lesser fibers from the paracentral, anterior ventral and lateral ventral nuclei.
In addition, the ASs-MSs area receives fibers from the central lateral nucleus (CL).
Areas PLLS and ALLS were both found to project retinotopically upon the interjacent zone of the lateral posterior complex, as well as to the intermediate and suprageniculate divisions of the posterior nuclear group, the magnocellular division of the medial geniculate complex, the thalamic reticular complex, and central lateral nucleus.
Injections of 3H-leucine in cortical area 5a were associated with terminal labeling primarily in the spinal recipient zone of the ventral lateral nucleus (VLsp) and the medial division of the posterior group (POm).
In the lateral geniculate body of Tupaia labeled cells were found only in layer 3; some labeled cells were also found in the lateral nucleus.
Retrograde transport studies also indicate cortically projecting cells in the central lateral nucleus.
Afferents to electrophysiologically identified association response areas originate in the lateroposterior nucleus, ventroanterior nucleus, the pulvinar, the laterodorsal nucleus, and the central lateral nucleus.
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