[Physiologic and pharmacologic differences in 3 types of pyramidal cells identified by antidromic stimulation in the primary somatosensory cortex of the rat].

The physiological and pharmacological properties of three types of pyramidal neurons (pyramidal tract neurons, cortico-thalamic neurons and commissural neurons) identified by electrical antidromic stimulation were studied in the first somatic sensory cortex of the Rat. The laminar distribution of these neurons (as determined through histological reconstruction of the electrode tracks), their axonal conduction velocity, their sensitivity to iontophoretically applied acetylcholine and their ability to be driven by the stimulation of a peripheral somatic receptive field were shown to be different in the three groups. Some hypotheses are discussed, which could explain such differences.