Ginty, DavidZhang, Dawei2024-11-2020242024-11-192024Zhang, Dawei. 2024. A mechanosensory neural pathway mediating wet dog shakes. Doctoral dissertation, Harvard University Graduate School of Arts and Sciences.31559077https://nrs.harvard.edu/URN-3:HUL.INSTREPOS:37379815Dogs and other mammals perform stereotypical rapid oscillations of their head and upper trunk to remove water and other irritants contacting their back hairy skin, a behavior known as wet dog shakes. The somatosensory mechanisms underlying this stereotypical behavior are poorly understood. We report that Piezo2-dependent mechanosensation mediates wet dog shakes evoked by water or oil droplets applied to the dorsal neck hairy skin of mice. A survey of mechanosensory neuron types that underlie stimulus-evoked wet dog shakes revealed that unmyelinated low-threshold mechanoreceptors (C-LTMRs), which form lanceolate endings associated with vellus body hair follicles and had been implicated in affective, pleasurable touch, mediate this behavioral response to mechanical stimuli. C-LTMRs were strongly activated by oil droplets applied to hairy skin and, unlike several other LTMR types, their optogenetic activation evoked wet dog shakes. Moreover, ablation of C-LTMRs attenuated oil droplet evoked wet dog shakes. Centrally, we found that C-LTMRs are synaptically coupled to spinoparabrachial neurons, and optogenetic inhibition of spinoparabrachial neuron synaptic transmission and excitatory neurons of the parabrachial nucleus impaired both oil droplet- and C-LTMR-evoked wet dog shakes. Thus, a C-LTMR-spinoparabrachial pathway mediates wet dog shakes to remove water and possibly other mechanical irritants contacting back hairy skin.application/pdfenNeurosciencesThesis or Dissertation2024-11-200000-0001-5820-3810