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

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 (IR DIC) technique, together with blind patch clamp, electrophysiological characteristics of CA1 neurons from the selected hippocampal slices of healthy Sprague Dawley rats were recorded in whole cell mode. RESULTS: The morphology of somata and axon were observed non invasively 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 after discharges, 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 real time observation in electrophysiological experiments.