Infrared video patch-clamp technique for spiral ganglion neurons in rat cochlear slices.

CONCLUSION:Cochlear slice and infrared video patch-clamp techniques can be used in real-time observation. They provide a good method and platform for further study of the electrophysiological properties and auditory transduction mechanism of spiral ganglion neuron (SGN). OBJECTIVE:To establish the isolated rat cochlear slice technique combined with the infrared video patch-clamp technique to explore the electrophysiological properties of the SGN. MATERIALS AND METHODS:SD rats were divided into three groups according to postnatal days (0-2 days, 3-6 days and 7-14 days). After quickly making SD rat cochlear slices, the electrophysiological properties of the SGN were observed using the infrared differential interference contrast technique and patch-clamp recording, and the factors that affect the cochlear slice quality and patch-clamp recording were analysed. RESULTS:The successful slice rate was highest in 3-6-day-old SD rats and two to four slices could be prepared using each cochlea. It is crucial to maintain the connection of partial skull with the cochlea and the volute integrity when producing slices. The position of the cochlear axis and blade, and the slice preparation time were also important factors affecting slice quality and cell activity. SGN cells in good condition could easily be found using the infrared video patch-clamp technique to help the assessment of the seal test process. SGN resting membrane potential of whole-cell recording was -45.6+/-5.3 mV (n=52) and the currents of Na+ and K+ could be recorded.