Thalamic and basal forebrain cholinergic connections of the rat posterior parietal cortex

THE thalamic connectivity and basal forebrain cholinergic input to the post erior parietal cortex (PPC) of Long-Evans rats was examined using combined retrograde tracing and immunocytochemical methods. As in previous studies, the PPC could be distinguished by its input from the lateral posterior, lat eral dorsal, and posterior nuclei of the thalamus, but not the lateral geni culate nucleus or ventrobasal complex. These nuclei were also observed to r eceive reciprocal projections from the ipsilateral PPC. Cholinergic neurons innervating the PPC were primarily localized to the substantia innominata/ nucleus basalis region. The implications of these data for possible functio ns of the cholinergic input to PPC are discussed. NeuroReport 10:941-945 (C ) 1999 Lippincott Williams & Wilkins.