Function of axonal hyperpolarization activated currents

小脑苔藓纤维提供了利用膜片钳直接记录行进中的突触前钮扣来分析有髓鞘的中央轴突的机会。小脑苔藓纤维钮扣（cMFBs）产生超快动作电位（半持续时间100µs），其频率可高于1 kHz。此外，cmfb表现出显著的超极化激活电流（I_h）。尽管有大量的研究，但I_h在轴突中的功能在很大程度上仍不清楚。因此，cmfb为直接研究I_h在轴突中的功能提供了独特的机会。本课题将验证I_h促进高频动作电位的产生，加快动作电位的传播速度，并通过肾上腺素的调节调节轴突的功能。为了验证这些假设，将主要使用先进的电生理技术。预期结果具有普遍意义，并有助于更好地理解轴突中动作电位的传播受损的疾病。

Cerebellar mossy fibers offer the chance to analyze myelinated central axons with direct patch clamp recordings at en-passant presynaptic boutons. Cerebellar mossy fibers boutons (cMFBs) generate ultrafast action potentials (half duration 100 µs), which can occur at frequencies higher than 1 kHz. Furthermore, cMFBs exhibit a prominent hyperpolarization activated current (I_h). Despite intense research the function of I_h in the axon remains largely unclear. Therefore, cMFBs offer the unique chance to directly investigate the function of I_h in axons. In the proposed project the hypotheses will be tested that I_h facilitates the generation of high-frequency action potentials, accelerates the speed of action potential propagation, and via modulation by Epinephrine regulates the function of axons. To investigate these hypotheses advanced electrophysiological techniques will mainly be used. The expected results are of general interest and could contribute to a better understanding of diseases, in which the propagation of action potentials in axons is impaired.