Activity of identified cerebral neuron correlates with food-induced arousal in Aplysia.

Firing of the cerebral-pedal regulator neuron, C-PR, evokes a constellation of responses which are characteristic of the food-induced arousal state that occurs following exposure of Aplysia to seaweed. To provide further evidence that C-PR plays a role in generating the food-induced arousal state, extracellular recordings from the cerebral-pedal connective, which contains the axon of C-PR, were obtained in freely moving animals. The C-PR spike in the connective recorded in vivo was then identified by comparing the wave form to the obtained by firing C-PR in an in vitro preparation. We report here that C-PR activity is evoked by food stimulation, and increased firing of the C-PR is closely correlated with appetitive head lifting, the first manifestation of the food arousal state.