Functional organization of local neural networks in the cat neocortex. Relationship to the level of food motivation.

Implanted semimicroelectrodes were used to record multineuron activity--spike discharges from groups of close-lying neurons--in the deep layers of the frontal and motor cortex in conscious cats with different levels of food motivation. Spike activity from 4-7 neurons was extracted from multineuron activity, and interneuron interactions were studied by cross-correlation analysis. Neurons in local networks were divided into two subgroups: neurons with high-amplitude spikes with a predominance of output (divergent) connections, and neurons with low-amplitude spikes and a predominance of input (convergent) connections. Food deprivation lasting 24 h affected mainly the nature of interneuron interactions in the range of late cross-correlational connections (with delays of 2-100 msec).