Measurement of Ca2 + Flow in Cochlear Cells Using Non–Invasive Micro–Test Technique

ObjectiveTo test Calcium ion (Ca2 +) flow at the head and end of outer hair cells (OHCs) in resting state and in response to Nimodipine treatment.MethodsNon–invasive micro–test techniques were used to study Ca2+ in isolated OHCs in adult guinea pigs.ResultsFour types of Ca2 + transport were identified in OHCs on basilar membrane tissue fragments: influx at the head of with efflux at the bottom(type 1): efflux at the head of OHCs with influx at the bottom (type 2); influx at the both head and bottom (type 3); and efflux at the both head and bottom (type 4). However, only type 1 and type 3 of Ca2 + ion transport were detected in the cochlea. We propose that Ca2 + ion transport exists in adult guinea pig cochlear OHCs in resting state and is variable. Ca2 + flow in OHC can be inhibited by Nimodipine in resting state.