Neuronal mechanisms of pheromone sensing
Chemosensory cues are known to influence sexual behavior and reproductive physiology. Yet, how the olfactory system impinges onto different output neurons in the brain that are mediating these effects remains largely unknown. We would like to dissect the underlying neural circuitry and study the fundamental physiological mechanisms that govern reproduction in mice by integrating genetic, molecular, cellular, and system approaches. In this next funding period we propose to focus our analysis on the functional role of the newly-identified GnRHR neuron populations in the amygdala and PAG, respectively. Our previous results demonstrate that GnRHR neurons in these areas respond reproducibly to extracellular application of GnRH. Based on these results, we hypothesize that neuroendocrine state-dependent activation of amygdala GnRHR neurons will contribute to olfactory memory whereas pheromone-triggered activation of PAG GnRHR neurons will modulate female sexual (lordosis) behavior. We will directly test these hypotheses in living animals using fiber optics and light pulses while monitoring the animal's behavior.