Mechanisms regulating the activity of facial nucleus motoneurones--1. Antidromic activation.
The antidromic activation of facial nucleus montoneurones has been studied in acute experiments on cats by means of extra- and intracellular recording techniques. Time and amplitude characteristics of separate components of the antidromic action potential and the after--potentials accompanying it have been analyzed. A correlation is found between the duration of the falling phase of the soma-dendritic component of the action potential, the duration of its after-hyperpolarization and impulse conduction time in the axon. The dendritic origin of after-depolarizing processes is shown. It is concluded that, since there is no recurrent collateral pathway in facial motoneurones, the modulating effect of spike after-potentials on the proper excitability of facial motoneurones acquires great functional significance.
D000200:Action Potentials; D000818:Animals; D001369:Axons; D002415:Cats; D005071:Evoked Potentials; D005154:Facial Nerve / Q000033:anatomy & histology / Q000502:physiology*; D009046:Motor Neurons / Q000166:cytology / Q000502:physiology*; D009431:Neural Conduction; D011149:Pons / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology