Electrophysiological characteristics of rat hippocampal CA1 neurons by infrared visual patch clamp method

    LEI Geª²Sheng, WAN Yeª²Hong, WANG Yuª²Ying, ZHU Junª²Ling, HU Sanª²Jue

    Institute of Neuroscience, Fourth Military Medical University, Xi¡¯an 710033, China

    ¡¾Abstract¡¿ AIM: To establish the visual patch clamp method and to observe the electrophysiological characteristics of rat hippocampal CA1 neurons. METHODS: By using infrared differential interference contrast (IRª²DIC) technique, together with blind patch clamp, electrophysiological characteristics of CA1 neurons from the selected hippocampal slices of healthy Spragueª²Dawley rats were recorded in wholeª²cell mode. RESULTS: The morphology of somata and axon were observed nonª²invasively by patch clamp with infrared videomicroscopy. There were two types of CA1 neurons, among which, pyramidal neurons had no or low rate of spontaneous discharges and low membrane resistance with frequency adaptation and afterª²discharges, whereas interneurons had high rate of spontaneous discharges and high membrane resistance but with no frequency adaptation. CONCLUSION: Patch clamp with infrared videomicroscopy method, better than the traditional blind patch clamp method, can be used to make direct realª²time observation in electrophysiological experiments. ......