Antidromic activation of pyramidal tract neurons following topical penicillin application. A possible mechanism in the generation of paroxysmal events.
Pyramidal tract (PT) neurons identified through antidromic stimulation were recorded with extracellular multibarrelled microelectrodes in the rat motor cortex. Topical application of small amounts of penicillin to the PT fibers at the medullary level induced the generation of action potentials (APs) near the injection site. These APs, which propagated antidromically to the cortex, could be characterized by collision test. It is suggested that a similar phenomenon may occur on intracortical collaterals of PT fibers within a cortical penicillin focus. Such 'ectopic' AP generation may contribute significantly to the generation of paroxysmal events.
Louvel
J
J
Unité de Recherches sur l'Epilepsie, INSERM U.97, 2 ter, rue d'Alésia, 75014 Paris, France.
Pumain
R
R