Rat Merkel cells are mechanoreceptors and osmoreceptors.

Rat Merkel cells are mechanoreceptors and osmoreceptors.

Blog Article

Merkel cells (MCs) associated with nerve terminals constitute MC-neurite complexes, which are involved in slowly-adapting type I mechanoreception.Although MCs are known to express voltage-gated Ca2+ channels and hypotonic-induced membrane deformation is known to lead to Ca2+ transients, whether MCs initiate mechanotransduction is currently unknown.To Mirror answer to this question, rat MCs were transfected with a reporter vector, which enabled their identification.Their properties were investigated through electrophysiological studies.Voltage-gated K+, Ca2+ and Ca2+-activated K+ (KCa)channels were identified, as previously described.

Here, we also report the activation of Ca2+ channels by histamine and their inhibition by acetylcholine.As a major finding, we demonstrated that direct mechanical stimulations induced strong inward Ca2+ currents in MCs.Depolarizations were dependent on the strength and the length of the stimulation.Moreover, touch-evoked currents were inhibited by the stretch channel antagonist gadolinium.These data confirm the mechanotransduction capabilities of MCs.

Furthermore, we found that activation of the osmoreceptor TRPV4 in FM1-43-labeled MCs provoked neurosecretory granule exocytosis.Since FM1-43 blocks mechanosensory channels, this suggests that hypo-osmolarity activates MCs in the absence of mechanotransduction.Thus, mechanotransduction and osmoreception are Colognes likely distinct pathways.