Meeting Abstract

P2.128  Tuesday, Jan. 5  Orexin/hypocretin immunoreactivity in the brains of fed and fasted ball pythons (Python regius) RUIZ, ME*; MCNERNEY, CA; HORNUNG, KL; TAYLOR, EN; STRAND, CR; Allan Hancock College; Cal Poly State Univ.; Cal Poly State Univ.; Cal Poly State Univ.; Cal Poly State Univ. cstrand@calpoly.edu

Orexin/hypocretin peptides are involved in food intake, energy balance, and regulation of sleep/wake states. The distribution of orexin-immunoreactive(ir) cells and fibers in the brains of birds, mammals, lizards, and amphibians has been documented. Various hypothalamic nuclei contain the soma of orexinergic neurons, depending on the taxa. Differences in the location of orexinergic neurons between taxa may indicate roles for this neuropeptide in regulation of homeostasis. Although in mammals there is not a difference in the expression of orexin based on food intake, central orexin administration does stimulate feeding. The goal of this experiment was to investigate the distribution of orexin-ir cells and fibers in the brains of fed and fasted ball pythons, Python regius. Since pythons eat infrequently and exhibit numerous physiological responses to feeding, they will make for an interesting comparison to other vertebrates in identifying the role orexins may play in regulating feeding behavior and energy homeostasis.