Role of Ghrelin in Modulating Motivational Components of Reproduction

Reproductive fitness and physiology are tightly coupled with, and dependent upon, metabolic needs and energy balance. The main objective of the current thesis was to investigate the effects of ghrelin acting on the medial preoptic area (mPOA) and the ventral tegmental area (VTA) on the anticipatory and consummatory aspects of male sexual behaviour. Results from the first experiment suggest that ghrelin acts on the mPOA to inhibit sexual appetitive behaviours and shorten copulatory behaviours without influencing food consumption. In the second experiment, ghrelin receptor antagonism in the VTA reduces anticipatory behaviour when compared to saline. The current research supports the idea that the availability of oxidizable fuels, and its subsequent neurochemical signals, may set the stage for the quantities and sensitivity of several neuropeptides and neurotransmitters acting on critical brain regions involved in reproductive appetitive behaviors.