Olfaction is one of our five basic external senses, and a principal mechanism by which we perceive the external world. Sensory receptors define our capacity for perception, and we identified novel olfactory receptor families (TAARs, FPRs), opening up new avenues of research to probe the neuronal basis of perception and behavior. We discovered ligands for many TAARs, including ethological odors derived from carnivores, male mice, and carrion that evoke innate aversion or attraction responses. We also identified a pheromone of juvenile mice that inhibits adult sexual behavior, and uncovered a noncanonical mechanism for sweet taste detection in hummingbirds that involved transformation of the ancestral umami receptor. Together, our work provides a molecular framework for understanding how sensory inputs are processed to evoke variable and complex behaviors.

Recently, my lab began exploring internal sensory systems of the vagus nerve, a major body-brain connection that controls autonomic physiology. Vagal sensory mechanisms are largely unresolved and present tremendously important problems in sensory biology. We used a molecular approach to deconstruct the vagus nerve, identifying novel receptors and classifying principal cell types, and a genetic approach to map, image, ablate, and stimulate vagal neuron subtypes. We defined sensory neurons that innervate the lung and control breathing, and others that innervate the gastrointestinal tract and control digestion. Receptor identification studies identified a critical role for the mechanoreceptor Piezo2 in the sensation of lung stretch. Identifying neurons and receptors that control autonomic physiology builds an essential foundation for mechanistic study and therapy design.