Meeting Abstract
Adaptation requires successful reproduction, but reproductive processes are energetically expensive and can compromise the chances of survival during energetic challenges. Previous work examined the inhibition of the hypothalamic-pituitary-gonadal system and stimulation of food intake during severe energetic challenges by chemical messengers, including the RFamide-related peptide, gonadotropin-inhibiting hormone (GnIH). Recently, we examined the role of GnIH in female Syrian hamsters under mild energetic challenges with particular attention to appetitive behaviors, such as food hoarding and the preference for spending time with male conspecifics. We found a strong link between brain GnIH cell activation and food restriction-induced changes in appetitive, but not consummatory behaviors. Food restriction-induced increases in GnIH cell activation and food hoarding and decreases in sexual motivation were apparent on all days of the estrous cycle except the day of proestrous and in ovariectomized (OVX) females, but not in OVX females treated with progesterone alone or estradiol plus progesterone. Central treatment with GnIH in ad libitum-fed females was sufficient to significantly decrease preference for males and produce transient increases in food hoarding, but substantial knock down of GnIH gene transcription by RNA interference had no effect on food restriction-induced changes in appetitive behaviors. Thus, in environments where energy availability fluctuates, reproductive success may be optimized by the interactive effects of GnIH (and possibly other peptides) with progesterone on appetitive but not consummatory behavior. Funded by NSF grants IOS-1257638 and IOS-1257876.
