Regional differences in itch transmission

Georgia Tech Research Corporation, Atlanta GA

Investigators

Abstract

The nervous system allocates disproportional neuronal resources to sensory information that are critical for an organism’s survival and reproduction. For example, the skin of the palms of the hands, especially the figure tips, have the highest density of touch sensors to allow object recognition and manipulation. This proposal aims to use the itch-sensing neural circuit as a model system to understand how the mammalian nervous system achieves higher sensitivity of sensory processing in the glabrous (non-hairy) skin. The PI’s group previously identified MrgprC11+ neurons as the main mediator for itch sensation arising from both the proximal body and the glabrous skin of mice. This project will examine the morphological and physiological features of MrgprC11+ neurons to provide a mechanistic understanding of regional differences in sensory processing. The project will support the training of undergraduate and graduate students. The project will also provide high school science teachers with hands-on experience to analyze neuronal connections and promote neuroscience education in high schools. Overall, this project will broaden our scientific and societal understanding of itch sensation. Disproportional central representation of the glabrous skin is the most striking feature of the somatosensory cortical map. However, where in the somatosensory circuits such biased representations emerge and the molecular and cellular basis underlying the distorted representation are largely unknown. This project will analyze the MrgprC11+ itch-sensing dorsal root ganglia neurons controlling different body locations to investigate how primary sensory neurons contribute to the distorted cortical representation. A combination of morphological, transcriptomic, and physiological approaches will be employed to address three specific aims. Aim 1 will determine the morphological basis of regional differences in itch transmission and how this is established during development. Aim 2 will identify the skin-type specific physiological properties of itch-sensing neurons to achieve heightened glabrous skin sensitivity. Aim 3 will investigate skin-type specific synapse formation and pruning mechanisms to promote itch transmission of the glabrous skin. Results generated will deepen our understanding of the somatotopical organization of the nocifensive sensory system in vertebrates. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.