Electrophysiological concomitants of eating induced from neocortex and hippocampus by electrical stimulation and injection of KC1 or norepinephrine.

EEG and DC activity were recorded from the hippocampus and neocortex in freely moving rats during consummatory behavior elicited by electrical stimulation and application of KC1 or norepinephrine to these structures. Eating induced by KC1 application or electrical stimulation of the neocortex or hippocampus was accompanied by single or multiple waves of spreading depression (SD), i.e., by traveling slow potential change. An analysis of single vs. multiple cortical SD waves indicated that when multiple waves occurred, feeding was elicited by the first wave. Injection of norepinephrine into the hippocampus resulted in a significantly larger and qualitatively different feeding response compared to KC1 injections. No apparent changes in the EEG or DC activity occurred upon norepinephrine injections.