Effects of resveratrol on intrinsic neuronal properties of CA1 pyramidal neurons in rat hippocampal slices

Introduction: Resveratrol possesses a wide range of biological effects. However, the cellular mechanisms of its effects are not fully understood. In the present study, the cellular actions of resveratrol on intrinsic electrophysiological properties of the rat hippocampal CA1 pyramidal neurons were examined. Methods: The spontaneous and evoked firing properties of CA1 pyramidal neurons in adult rats exposed to resveratrol (100 mu M) were examined using whole cell patch clamp recording under current clamp condition and the results were compared with control and vehicle treated groups. Results: Treatment with resveratrol caused alterations in neuronal firing characteristics. Application of resveratrol shifted the resting membrane potential (RMP) towards hyperpolarizing voltage (from -58.62 +/- 0.89 mV in control to 67.06 +/- 0.89 mV after resveratrol). The after hyperpolarization potential (AHP) amplitude was significantly increased following extracellular application of resveratrol (P < 0.001). It also induced a significant increase in the peak amplitude of action potential in response to 100-300 pA depolarizing current pulses (P < 0.05). Furthermore, resveratrol-treated neurons displayed a significantly increased time to peak in response to 400 and 500 pA depolarizing currents, when compared with either control or vehicle-treated groups (P < 0.05). In addition, rise time to half-amplitude as well as rise tau and decay tau of action potential were significantly increased following resveratrol application (P < 0.01, P < 0.01 and P < 0.01, respectively). Conclusion: Treatment with resveratrol changes the action potential parameters, hyperpolarizes the RMP and reduces neuronal excitability and thereby may probably induce neuroprotective effects.