Abstract
Food intake affects neuroendocrine and behavioural responses to stressful stimuli. Peripheral administration of cholecystokinin, a satiety factor, activates prolactin-releasing peptide (PrRP) neurones. PrRP neurones have been suggested to play a facilitative role in ACTH and oxytocin release after stressful stimuli. We investigated whether PrRP also plays a role in behavioural stress responses. We examined effects of icv administration of PrRP and anti-PrRP antibody upon fear/anxiety behaviour in response to stressful stimuli in rats. Icv administration of PrRP reduced anxiety-related behaviour in an elevated plus maze test, while administration of anti-PrRP IgG increased it. On the other hand, PrRP administration increased plasma oxytocin concentrations and administration of anti-PrRP IgG attenuated plasma oxytocin increase after fear-related stimuli. All these data suggest that PrRP neurones have differential effects upon neuroendocrine and behavioural responses to stress. PrRP neurones may play a role in food intake-associated modulation of neuroendocrine and behavioural responses to emotional stress. [Jpn J Physiol 55 Suppl:S17 (2005)]
