Direct measurement of the action of acetylcholine on isolated outer hair cells of the guinea pig cochlea.

摘要: Acetylcholine has long been thought to be the neurotransmitter of cochlear efferent system in mammals although evidence is largely indirect. By using whole-cell recordings from isolated outer hair cells, we show that acetylcholine activates a large rapidly desensitizing outward potassium current. This corresponds hyperpolarization membrane potential rest. The half maximal dose for was 13.5 $\mu $M with cooperativity 2. response not due conventional muscarinic action it blocked by 0.1 atropine and antagonists but could curare, suggesting shared many properties nicotinic receptor. It was, however, inhibited 10 strychnine. current activated required external calcium characterized significant delay at room temperature. points involvement second messenger system, possibly itself.