SYNAPTIC TRANSMISSION AT VERTEBRATE HAIR-CELLS

Mechanosensory hair cells release chemical transmitters onto associate d afferent dendrites and respond to transmitters re leased by efferent neurons. Dihydropyridine-sensitive, voltage-gated calcium channels su pport transmitter release from hair cells and may be expressed prefere ntially at release sites, Recently, a novel subunit of the nicotinic a cetylcholine receptor family, alpha 9, was identified and found to be expressed in rat hair cells. It appears to mediate efferent inhibition via associated calcium-activated potassium channels.