Abstract
Experiments were done to elucidate properties of the late N-wave which was induced in vitro in thin sections of the olfactory cortex of the rat in response to stimulation of the lateral olfactory tract. The late N-wave decreased in size at a stimulation rate of more than once every 90 s or at temperatures higher than 27.degree. C. The late N-wave was suppressed in the presence of GABA, picrotoxin or bicuculline or in the Cl-free medium. Penicillin or pentylenetetrazol, which blocked actions of GABA on the presynaptic potential, also suppressed the late N-wave. The late N-wave first appeared at postnatal ages of 18-25 days. The late N-wave reversed in polarity when recorded from the deep layers of the sections or from the cut surface of the sections. Single cells in the deep portions of the sections discharged during the late N-wave. Cells in the superficial layers fired just before or after the late N-wave. To explain these observations, a neuronal model for generation of the late N-wave was presented.