The Role of Sensory Neurons Innervating Internal Organs

Projection Summary Over the last decades, we have made tremendous advancements in understanding the role of somatosensory neurons in sensing exteroceptive signals including touch, temperature, and pain. However, somatosensory neurons also innervate internal organs, but we understand much less about the anatomy and physiology of these neurons. There is literature on the roles of interoceptive neurons in sensing lung stretch and blood pressure. These studies mainly focus on the Vagal Nodose ganglia that innervate many internal organs. However, dorsal root ganglia (DRG) neurons, in addition to innervating skin and muscle, also innervate disparate internal organs but have garnered much less focus. To begin to elucidate the structure and function of these sensory neurons, we focus on adipose-innervating DRG neurons. These neurons are an attractive starting point because very little is known about their form and function, but these neurons could potentially have a profound relationship with the autonomic nervous systems (for example, the sympathetic nervous system) and roles in whole-body physiology. Here, we show that fat depots are robustly innervated by DRG neurons. We have also collected important preliminary data molecularly defining the subset of DRGs that innervate fat depots, and have begun to address their interactions with the sympathetic activities. We propose to use state-of-the-art and innovative molecular and genetic techniques to map adipose-innervating DRG neurons, profile their identities, and test their function.