TRPM4 mediates a subthreshold membrane potential oscillation in respiratory chemoreceptor neurons that drives pacemaker firing and breathing.

ABSTRACT: Brainstem networks that control regular tidal breathing depend on excitatory drive, including from tonically active, CO₂/H⁺-sensitive neurons of the retrotrapezoid nucleus (RTN). Here, we examine intrinsic ionic mechanisms underlying the metronomic firing activity characteristic of RTN neurons. In mouse brainstem slices, large-amplitude membrane potential oscillations are evident in synaptically isolated RTN neurons after blocking action potentials. The voltage-dependent oscillations are abolished by sodium replacement; blocking calcium channels (primarily L-type); chelating intracellular Ca²⁺; and inhibiting TRPM4, a Ca²⁺-dependent cationic channel. Likewise, oscillation voltage waveform currents are sensitive to calcium and TRPM4 channel blocke

SUBMITTER: Li K 

PROVIDER: S-EPMC7888550 | biostudies-literature | 2021 Feb

REPOSITORIES: biostudies-literature