INTRACEREBROVENTRICULAR INFUSION OF THE CCKB RECEPTOR AGONIST PENTAGASTRIN POTENTIATES ACOUSTIC STARTLE

The acoustic startle reflex is increased by stimuli associated with av ersive events (such as the delivery of shock) and so has been used sen sitive index of 'anxiety' or 'fear'. Administration of cholecystokinin (B) (CCKB) receptor agonists produces a constellation of behaviors ass ociated with 'anxiety' in laboratory animals and humans. Here, intrace rebroventricular infusions of the CCKB agonist, pentagastrin (0, 1, 10 , 100 nM), produced a long-lasting, dose-related potentiation of acous tic startle responses. Similar infusions of pentagastrin had no effect on locomotor activity over the same time course, showing that changes in startle responsivity following infusions of pentagastrin are not d ue to nonspecific changes in motor activity.