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Inhibition of monosynaptic and polysynaptic reflexes and muscle tone by electrical stimulation of the cerebral cortex

1967; Elsevier BV; Volume: 17; Issue: 2 Linguagem: Inglês

10.1016/0014-4886(67)90142-2

1090-2430

Eberhardt K. Sauerland, T. Knauss, Yoshio Nakamura, Carmine Clemente,

Paranormal Experiences and Beliefs

Electrical stimulation of the rostral end of a forebrain inhibitory and EEG synchronizing system has resulted in suppression of motor behavior, induction of sleep, and inhibition of the monosynaptic masseteric reflex in cats and monkeys. The experiments reported here are concerned with a closer examination of the inhibitory effects exerted by the cortical end of this system on somatic reflexes at different levels of the neuraxis and in various stages of vigilance in the adult cat. Electrical stimulation, consisting of a short train of pulses, was applied to the rostral portion of the orbital gyrus. Following the train of impulses to the cortex, test reflexes were electrically elicited, and the effects of cortical stimulation on reflex discharges were studied. Electrical stimulation of the cortical inhibitory area resulted in immediate and consistent inhibition of a variety of monosynaptic and polysynaptic reflexes at different levels of the neuraxis. This inhibition was diffuse and nonreciprocal when the concurrently recorded EEG was synchronized. On the other hand, reflexes for antigravity muscles were inhibited and those for their antagonists facilitated, when the EEG was desynchronized. Additionally, diffuse inhibition of spontaneous muscle tone and synchronization of the EEG were obtained by electrical stimulation of this same cortical area. These findings provide some neurophysiological basis for an understanding of forebrain inhibitory mechanisms.