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Direct excitatory interactions between spinal motoneurones of the cat.

1977; Wiley; Volume: 272; Issue: 3 Linguagem: Inglês

10.1113/jphysiol.1977.sp012071

1469-7793

P. Gogan, J. P. Guéritaud, G. Horcholle‐Bossavit, Suzanne Tyč-Dumont,

Cellular Mechanics and Interactions

1. Ninety‐seven spinal motoneurones were identified by their antidromic invasion following stimulation of the muscle nerve and submitted to a series of four tests to reveal a possible direct excitation between motoneurones. 2. Threshold differentiation, refractoriness, hyperpolarization and collision revealed antidromically induced depolarizations in fourteen of the ninety‐seven tested motoneurones. 3. The parameters of the antidromically induced depolarizations indicate a short latency, a low amplitude and independence with regard to the membrane polarization. 4. It is concluded that the antidromically induced depolarizations reached the impaled motoneurone via a route other than its own axon. 5. The mechanism may involve either electrotonic interactions between neighbouring motoneurones or excitatory recurrent collaterals between synergist motoneurones.