[Electrical properties of membranes of motor neurons innervating the masseter muscle in rats].

Membrane resting and action potentials evoked by antidromic and direct stimulation were studied in neurons of the rat trigeminal motor nuclei. It is shown that in the given motor nuclei there are cell populations both with low and high membrane potentials. Motoneurons with high resting potentials were characterized by shorter latent period of antidromic activation, longer duration of spike and after depolarization and lower input resistance. Bimodal character of electrophysiological parameters distribution in the trigeminal motor nuclei show that "slow" and "fast" fibres of m. masseter may be innervated by different types of motoneurons.