Laboratório de Eletrofisiologia, Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza 60714-903, CE, Brazil.
University of Tennessee Health Science Center, Memphis, TN, USA.
Brain Res. 2020 Feb 15;1729:146599. doi: 10.1016/j.brainres.2019.146599. Epub 2019 Dec 13.
Diabetic neuropathy is the most prevalent complication associated with diabetes mellitus (DM). The superior cervical ganglion (SCG) is an important sympathetic component of the autonomic nervous system. We investigated the changes in cellular electrophysiological properties and on NaK-ATPase activity of SCG neurons of rats with DM induced by streptozotocin (STZ). Three types of action potentials (AP) firing pattern were observed in response to a long (1 s) depolarizing pulse. Whilst some neurons fired a single AP (single firing phasic, SFP), others fired few APs (multiple firing phasic, MFP). A third type fired APs during more than 80% of the stimulus duration (tonic-like, TL). The occurrence of SFP, MFP and TL was 84.5, 13.8, and 1.7%, respectively. SFP and MFP differed significantly in their membrane input resistance (R). At the end of the 4th week of its time course, DM differently affected most types of neurons: DM induced depolarization of resting membrane potential (RMP), decreased AP amplitude in SFP, and decreased R in MFP. DM decreased spike after-hyperpolarization amplitude in MFP and the duration in SFP. Based on the RMP depolarization, we investigated the NaK-ATPase action and observed that DM caused a significant decrease in NaK-ATPase activity of SCG. In conclusion, we have demonstrated that DM affects several parameters of SCG physiology in a manner likely to have pathophysiological relevance.
糖尿病性神经病是与糖尿病（DM）相关的最普遍的并发症。颈上神经节（SCG）是自主神经系统的一个重要交感成分。我们研究了链脲佐菌素（STZ）诱导的 DM 大鼠 SCG 神经元的细胞电生理特性和 NaK-ATP 酶活性的变化。在对长（1 s）去极化脉冲的反应中观察到三种类型的动作电位（AP）发射模式。虽然一些神经元发射单个 AP（单发射相，SFP），但其他神经元发射几个 AP（多发射相，MFP）。第三种类型在超过 80%的刺激持续时间内发射 AP（类紧张型，TL）。SFP、MFP 和 TL 的发生频率分别为 84.5%、13.8%和 1.7%。SFP 和 MFP 在膜输入电阻（R）上有显著差异。在其时间过程的第 4 周结束时，DM 以不同的方式影响大多数类型的神经元：DM 诱导静息膜电位（RMP）去极化，SFP 中的 AP 幅度降低，MFP 中的 R 降低。DM 降低了 MFP 中的后超极化幅度和 SFP 中的持续时间。基于 RMP 的去极化，我们研究了 NaK-ATP 酶的作用，并观察到 DM 导致 SCG 的 NaK-ATP 酶活性显著降低。总之，我们已经证明 DM 以可能具有病理生理学相关性的方式影响 SCG 生理学的几个参数。
