| Abstract: | Characteristics of focal potentials and single unit responses of the dorsomedial nucleus of the thalamus to electrical stimulation of the anterior periamygdalar cortex (APC) and area amygdaloidea anterior (AAA) were compared in acute experiments on rats. Differences were found in the parameters, dynamics, and duration of the recovery cycle of focal potentials in response to stimulation of APC and AAA. Stimulation of APC and AAA was accompanied by changes in the discharges of 26.9 and 19.2% of neurons studied respectively. Four types of unit responses are described: activating (64.3% of responding cells), biphasic activating (14.3%), inhibitory or inhibitory-activating (14.3%), and complex (7.1%). Spontaneous activity was exhibited by 25% of reacting cells. Stimulation of APC was shown to give rise to both shortlatency (12–18 msec) and long-latency (23–66 msec) phasic activating responses of the neurons whereas the latent periods of the analogous responses to stimulation of AAA exceeded 20 msec (from 21 to 136 msec). Unit responses of the second type consisted of a principal phasic response of three or four spikes with mean latent periods of 9–19.1 msec, preceded by a single short-latency (2.9–4.1 msec) spike. Responses of the first two types were characteristic of 92.9 and 64.3% of neurons responding to stimulation of APC and AAA respectively.Institute of Higher Nervous Activity and Neurophysiology, Academy of Sciences of the USSR, Moscow. Translated from Neirofiziologiya, Vol. 13, No. 6, pp. 604–611, November–December, 1981. |
