PROCTOLIN-LIKE IMMUNOREACTIVITY IN DORSAL PAIRED MEDIAN NEURONS GENERATING PLATEAU ACTION-POTENTIALS IN COCKROACH PERPLANETA-AMERICANA

The proctolinergic nature of dorsal paired median (DPM) neurons genera ting plateau action potentials (PAPs) of the cockroach CNS has been de monstrated using a double labelling technique (lucifer yellow staining and proctolin-like immunochemistry). Electrophysiological results sup port morphological evidence that a direct pathway exists from axons pa ssing throughout the proctodeal nerves to electrically active DPM neur on somata. However, the occurrence of spike failure along the neuritic membrane and the existence of a neuritic spike initiating site has be en postulated because spontaneous PAPs recorded intracellularly were n ot associated on a one-to-one basis with peripheral axon spikes. (C) 1 997 Elsevier Science Ireland Ltd.