Topography of connections between primary somatosensory cortex and posterior complex in rat: a multiple fluorescent tracer study.

Thalamocortical connections between ipsilateral thalamus and the first somatic sensory area were traced with simultaneous injections of different fluorescent tracers. Labeled neuronal elements in the antero-medial part (POm) of the posterior nucleus (PO) were topographically organized as an up-right body representation that mirrored a map in the ventroposterior nuclei (VP). No topography was observed in the posterior part of PO. These findings suggest POm in rodents provides precisely organized projections, parallel with those from VP.