Thalamic Projections to Parietal Cortex

Abstract

Thalamic projections to parietal regions of cerebral cortex were investigated in the cat by retrograde degeneration and retrograde transport techniques. Studies of retrograde cellular changes indicate cortically projecting cells in the lateroposterior nucleus (LP), rostral pulvinar (Pul), and the ventral part of the laterodorsal nucleus (LD). When lesions were placed in the cortex of young kittens, clear chromatolytic changes and cell loss were also consistently observed in middle and caudal parts of the ventroanterior nucleus (VA). Investigations of retrograde transport following intracortical injections of horseradish peroxidase have confirmed the results of retrograde degeneration studies by demonstrating cortically projecting cells in VA, LP, LD, and Pul. Retrograde transport studies also indicate cortically projecting cells in the central lateral nucleus. Material from both experimental techniques demonstrates a loose topographic organization of the projections from the lateral thalamus. Anterior parts of LP project to the anterior lateral gyrus and anterior middle suprasylvian gyrus. Middle LP and rostral Pul project to the middle suprasylvian gyrus.

Laterodorsal nucleus of the thalamus: A processor of somatosensory inputs

“…Our data are consistent with previous findings, in several species, demonstrating that LD has reciprocal connections with the limbic cortical areas, including the cingulate, retrosplenial, and subicular cortex (Jones and Leavitt, 1974;Spiro et al, 1980;Kaitz and Robertson, 1981;Robertson and Kaitz, 1981;Sripanidkulchai and Wyss, 1986;Thompson and Robertson, 1987a;Wyss, 1990 ,1992;Shibata, 2000). There are also reports that LD interacts with the posterior parietal cortex (Robertson, 1977;Yeterian and Pandya, 1985;Schmahmann and Pandya, 1990;Reep et al, 1994). In addition, LD receives inputs from the visual cortex (areas 17 and 18, Thompson and Robertson, 1987a;Negyessy et al, 2000;Shinkai et al, 2005) and the second motor cortex (Shibata and Naito, 2005).…”

“…This pathway originates primarily from SpVi and processes vibrissae-related information through the laterodorsal nucleus of the thalamus (LD). Because LD neurons project preferentially to limbic cortical areas and to the posterior parietal cortex (Jones and Leavitt, 1974;Robertson, 1977;Spiro et al, 1980;Robertson and Kaitz, 1981;Sripanidkulchai and Wyss, 1986;Thompson and Robertson, 1987a;Schmahmann and Pandya, 1990;van Groen and Wyss, 1992;Reep et al, 1994;Shibata, 2000), we propose that this LD pathway may be involved in spatial orientation and learning involving vibrissae information.…”

Thalamic projections to the auditory cortex in the rufous horseshoe bat (Rhinolophus rouxi)

“…This projection pattern seems to be similar in rodents, in which the rostral part of LP (LPr) projects to areas of visual cortex and the caudal part (LPc) to auditory cortex in the temporal region (Robson andHall 1977, Caviness andFrost 1980). In the cat, although mostly studied as part of the visual system (e.g., Robertson 1976Robertson , 1977Bowman and Olson 1988), LP projections could account for the responsiveness to auditory stimuli found in the suprasylvian cortex, a region of multimodal convergence from auditory, visual, and somatic modalities dorsal to the primary AC (Stasiak and Glendenning 1998). LP in the monkey also projects to those parts of the posterior cingulate gyrus involved in visual and auditory memory (e.g., Shibata and Yukie 2003).…”

Thalamic Afferents to the Visual Cortex in the Cat Studied by Retrograde Axonal Transport of Horseradish Peroxidase; pp. 127–139

“…The crown of the middle suprasylvian gyrus has been said to receive fibers from the dorsal lateral, lateral pulvinar, medial pulvinar and lateral central nuclei, but re ceives only a few fibers from the posterior lateral nucleus [Niimi and Inoshita, 1971;Graybiel, 1972a;M/m/etal., 1974;Mizuno etal., 1975;Robertson, 1977).…”