The anterior border zones of primary somatic sensory (SI) neocortex and their relation to cerebral convolutions, shown by micromapping of peripheral projections to the region of the fourth forepaw digit representation in raccoons

Multiple somatosensory areas in the anterior parietal cortex of the California ground squirrel ( Spermophilus beecheyii )

“…In carnivores, a somatotopically organized field in a similar location has been described for the raccoon and termed kinesthetic cortex (KC; Johnson et al, 1982;Feldman and Johnson, 1988;Doetsch et al, 1988). In ferrets, four representations of the face have been described using electrophysiological recording techniques.…”

“…Likewise, there is a growing body of evidence for multiple fields in anterior parietal cortex in eutherian mammals such as cats , raccoons (Johnson et al, 1982;Feldman and Johnson, 1988), ferrets , megachiropteran bats (Krubitzer and Calford, 1992), and primates (Kaas, 1983;Kaas and Pons, 1988; see Johnson, 1990 for review). However, less is known about the organization of anterior parietal cortex in eutherian mammals such as rodents, which have a small neocortex, and a relatively simply organized brain.…”

Organization of somatosensory cortex in three species of marsupials,Dasyurus hallucatus, Dactylopsila trivirgata,and Monodelphis domestica: Neural correlates of morphological specializations

“…Abundant examples of this relationship are evident in studies of prototherian and eutherian mammals (e.g., Johnson et al, 1982;Chapin and Lin, 1984;see Johnson, 1990 for review). For instance, in the platypus, Krubitzer et al (1995b) demonstrated that at least 85% of SI, and most of the entire somatosensory neocortex (which includes somatosensory areas in addition to SI) is devoted to representing the bill.…”

“…16. Illustrations of body representations in primary somatosensory area (SI) in the raccoon (Johnson et al, 1982), cat , rat (Chapin and Lin, 1984), and squirrel (Sur et al, 1978). These animals demonstrate that representations of different body parts occupy different proportions of SI.…”

Distribution of neurons immunoreactive for parvalbumin and calbindin in the somatosensory thalamus of the raccoon

“…For instance, Doetsch et al (1988) found that clusters of relay neurons in VP of the raccoon project specifically to SI cortical areas representing small, glabrous skin fields; neurons near lamellar borders within VP-and cells scattered throughout VPI and Po-send fibers to SI areas representing larger heterogeneous skin fields. The response properties of neurons in glabrous regions are modality-and place-specific; those in heterogeneous regions are more characteristic of nonlemniscal than lemniscal pathways (Johnson et al, 1982). Unfortunately, possible laminar differences in the projections to SI have not been studied.…”