| Abstract: | Extracellular unit activity of the anterior and posterior zones of the cingulate cortex and also of the anterior and posterior cortical association areas was analyzed in unanesthetized rabbits. In the posterior zone considerably more cells (60%) responded to hippocampal stimulation than in the anterior zone (18%). In 43% of these cells in the posterior zone but only in 5% in the anterior zone, the responses followed the frequency of stimulation. Unit responses in the posterior zone could be divided into two discrete groups: those with short (12.3 ± 6.5 msec) and those with long (50.2 ± 10.0 msec) latent periods. Inhibitory phenomena also were well marked during hippocampal stimulation. More than one-third of cells of the cingulate cortex responded to stimulation of the posterior association zones by spikes which followed the stimulus, and by subsequent inhibition. Responses of this kind to stimulation of the anterior association zones were found in only a few cells in the anterior zone of the cingulate cortex. The results are discussed in the light of data from morphological investigations relating to connections between these structures.Institute of Biological Physics, Academy of Sciences of the USSR, Pushchino-on-Oka. Translated from Neirofiziologiya, Vol. 14, No. 3, pp. 270–277, May–June, 1982. |
