| Abstract: | Two models of postural tremor — induced by cold (shivering) and by injection of oxotremorine into the caudate nucleus (caudate tremor) — were compared in experiments on cats. Both models shared the same electromyographic picture of tremor; the frequency of activity of motor units working independently was 4–12 spikes/sec. Both types of tremor were potentiated by cold stimulation of temperature receptors and were inhibited by electrical stimulation of the medial preoptic region of the hypothalamus and by intravenous injection of cholinomimetics. Caudate tremor, unlike shivering, ceased after intravenous injection of scopolamine (an antiparkinsonism drug). On the basis of data on motoneuron function it is concluded that both types of tremor are analogs of physiological postural tremor. The selective inhibitory action of scopolamine on caudate tremor reflects only the mediator organization of structures in the caudate nucleus and cannot therefore serve as the basis for the conclusion that this disturbance of motor activity is a model of pathological postural tremor.O. V. Kuusinen Petrozavodsk State University. Translated from Neirofiziologiya, Vol. 13, No. 3, pp. 257–263, May–June, 1981. |
