[Analysis of the spike activity of pairs of caudate nucleus neurons in cats].

Spike activity of pairs of neurons was recorded simultaneously with a single microelectrode in the caudate nucleus of lightly anaesthetized immobilized cats. A high time correlation was observed in discharges of two neurons when their background activity showed group discharges. In case of unitary background activity, correlation between spike trains was observed only in 50% of the cells; it could be both of excitatory and inhibitory type. Many neuronal pairs exhibited negative short latency correlation in the 0--4 ms range. Electrical stimulation of different afferent inputs of the caudate nucleus caused minimal correlation between neuronal discharges and, on the contrary, abolished correlation between spontaneous discharges of the same pair of neurons. The presented results are discussed from the point of view of the caudate nucleus as an associative cerebral nucleus.