Septal-preoptic unit responses to microelectrophoresis of cholecystokinin, gastrin, vasoactive intestinal peptide and secretin in the rat.

Effects of microelectrophoretic application of cholecystokinin-8, gastrin-17, vasoactive intestinal peptide and secretin on activities of septal-preoptic neurons were examined in ovariectomized rats. All of the 4 peptides produced either excitatory or inhibitory responses in some neurons tested. No consistent relationship was observed between effects of different peptides, even between the peptides of the same family. These results provide electrophysiologic evidence for the action in the septal-preoptic region of these peptides, and suggest that there may be specific interneurons sensitive to a corresponding peptide with some overlapping.