PROJECT SUMMARY Taste buds are the sensory elements responsible for the detection and elaboration of the taste signal. In the anterior tongue, they are innervated by gustatory fibers (from the chorda tympani nerve) transmitting the signal to the brain but also by a rich network of somatosensory fibers (from the lingual branch of the trigeminal nerve) activated by nociceptive stimuli. This close proximity presents an ideal location to facilitate interactions between the two systems. The main goal of this project is to better understand and characterize these interactions at the tongue level, before further processing of the signal in the central nervous system. We will use a variety of techniques in combination with transgenic animals to test the hypothesis that various neuropeptides and neurotransmitters are released from somatosensory fibers and activate taste cells, which causes a modulation of gustatory responses. We will take advantage of optogenetics to specifically stimulate somatosensory fibers with light and study the effects of their activation on taste cells and taste responses. If successful, this exploratory research project will support the theory that interactions between the gustatory and somatosensory systems occur in the tongue and provide enough pilot data for a future grant application. The data collected will expand our understanding of the multi-modal aspect of food perception and ultimately, provide approaches to improve the hedonic value of nutritionally preferable foods.