Neocortical substance P neurons in the baboon: an immunohistochemical finding

Substance P-like immunoreactive (SP-LI) neurons have been demonstrated, by an avidin-biotin immunohistochemical method, in several neocortical areas in the brains of baboons. These neurons are mostly small in size, and are of many different somatic shapes, including bipolar and multipolar types. They occur in laminae III-VI but are most common in laminae V and VI. It is postulated that these neurons could contribute to previously-described cortical SP-LI fiber networks.