[HTML][HTML] The low-threshold calcium channel Cav3. 2 determines low-threshold mechanoreceptor function

A François, N Schüetter, S Laffray, J Sanguesa… - Cell reports, 2015 - cell.com
A François, N Schüetter, S Laffray, J Sanguesa, A Pizzoccaro, S Dubel, A Mantilleri…
Cell reports, 2015cell.com
The T-type calcium channel Cav3. 2 emerges as a key regulator of sensory functions, but its
expression pattern within primary afferent neurons and its contribution to modality-specific
signaling remain obscure. Here, we elucidate this issue using a unique knockin/flox mouse
strain wherein Cav3. 2 is replaced by a functional Cav3. 2-surface-ecliptic GFP fusion. We
demonstrate that Cav3. 2 is a selective marker of two major low-threshold
mechanoreceptors (LTMRs), Aδ-and C-LTMRs, innervating the most abundant skin hair …
Summary
The T-type calcium channel Cav3.2 emerges as a key regulator of sensory functions, but its expression pattern within primary afferent neurons and its contribution to modality-specific signaling remain obscure. Here, we elucidate this issue using a unique knockin/flox mouse strain wherein Cav3.2 is replaced by a functional Cav3.2-surface-ecliptic GFP fusion. We demonstrate that Cav3.2 is a selective marker of two major low-threshold mechanoreceptors (LTMRs), Aδ- and C-LTMRs, innervating the most abundant skin hair follicles. The presence of Cav3.2 along LTMR-fiber trajectories is consistent with critical roles at multiple sites, setting their strong excitability. Strikingly, the C-LTMR-specific knockout uncovers that Cav3.2 regulates light-touch perception and noxious mechanical cold and chemical sensations and is essential to build up that debilitates allodynic symptoms of neuropathic pain, a mechanism thought to be entirely A-LTMR specific. Collectively, our findings support a fundamental role for Cav3.2 in touch/pain pathophysiology, validating their critic pharmacological relevance to relieve mechanical and cold allodynia.
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