Behavioral effect of neuropeptides related to feeding regulation in fish

The hypothalamus, limbic system, and brainstem play an important role in the regulation of instinctive behavior. Many kinds of hypothalamic neuropeptides, such as orexin, ghrelin, neuropeptide Y, melanin-concentrating hormone, pituitary adenylate cyclase-activating polypeptide, corticotropin-releasing hormone, and diazepam-binding inhibitor-derived peptides, including the octadecaneuropeptide, have been implicated in the regulation of appetite and energy homeostasis in various models, including rodents and goldfish. Several of these neuropeptides also influence locomotor or psychomotor activity in rats and mice. The aim of this paper is to review the current knowledge on the psychophysiological effects of neuropeptides involved in the regulation of food intake in fish, and to examine their significance from a comparative point of view.