Synaptic cleft microenvironment influences potassium permeation and synaptic transmission in hair cells surrounded by calyx afferents in the turtle.

ABSTRACT:

Key points

In central regions of vestibular semicircular canal epithelia, the [K⁺ ] in the synaptic cleft ([K⁺ ]_c ) contributes to setting the hair cell and afferent membrane potentials; the potassium efflux from type I hair cells results from the interdependent gating of three conductances. Elevation of [K⁺ ]_c occurs through a calcium-activated potassium conductance, G_BK , and a low-voltage-activating delayed rectifier, G_K(LV) , that activates upon elevation of [K⁺ ]_c . Calcium influx that enables quantal transmission also activates I_BK , an effect that can be blocked internally by BAPTA, and externally by a Ca_V 1.3 antagonist or iberiotoxin. Elevation of [K

SUBMITTER: Contini D 

PROVIDER: S-EPMC7024053 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature