Linkage of neuron spike activity in the right and left amygdala in food motivation and emotional tension.

Cross-correlation histograms were plotted to study the linkage of spike activity in simultaneously recorded neurons in the central nucleus of the right and left amygdala in rabbits in calm waking, after 24 hours of food deprivation, in satiation, and in emotional tension (on presentation of dogs). Histograms showed peaks displaced from zero in 50-67% of cases. In hunger, many cases (52%) showed pairs in which the first neuron to discharge was in the left amygdala, this being followed by a neuron in the right amygdala (peaks from 10-50 and 130-150 msec). Firing in the opposite order was seen more rarely (36%). On presentation of dogs, there was an increase in the number of cases showing a common input to neurons, along with an increase in the leading role of neurons in the right amygdala (57%), due to increases in inhibitory influences from this area on cells in the left amygdala. The interaction of amygdalar neurons in these states was in most cases at frequencies in the delta range (74%), mainly at 2-4 Hz.