Aghajanian G K, Rasmussen K
Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut.
Synapse. 1989;3(4):331-8. doi: 10.1002/syn.890030406.
In general, it has been difficult to preserve electrophysiologically viable motoneurons in brain slices from adult mammals. The present study describes a new method for obtaining viable motoneurons in the facial nucleus of adult rat brain slices. The essence of the method was to use a modified artificial cerebrospinal fluid (ACSF) in which NaCl was replaced initially by sucrose; the modified ACSF was used during 1) preparation and 2) a 1 hr recovery period. The rationale for the modification is discussed in terms of the proposed acute neurotoxic effects of passive chloride entry and subsequent cell swelling and lysis. The actual recordings were made only after switching back to normal ACSF. Use of this method yielded large numbers of viable motoneurons that were suitable for intracellular recording; no motoneurons survived when normal ACSF (i.e., with NaCl) was used during slice preparation. A survey of some electrophysiological and pharmacological properties of facial motoneurons in this preparation, by means of current-clamp and voltage-clamp recording, revealed close similarities to the properties of adult motoneurons previously observed in vivo (e.g., time-dependent inward rectification, apamin-sensitive afterhyperpolarization, and serotonin-induced slow depolarization).
一般来说，在成年哺乳动物的脑片中保存电生理活性的运动神经元一直很困难。本研究描述了一种在成年大鼠脑片的面神经核中获取活性运动神经元的新方法。该方法的核心是使用一种改良的人工脑脊液（ACSF），其中最初用蔗糖替代氯化钠；在1）切片制备和2）1小时的恢复期间使用这种改良的ACSF。根据被动氯离子内流以及随后的细胞肿胀和裂解所提出的急性神经毒性作用，讨论了这种改良的原理。实际记录仅在换回正常ACSF后进行。使用这种方法产生了大量适合细胞内记录的活性运动神经元；在切片制备过程中使用正常ACSF（即含有氯化钠的）时，没有运动神经元存活。通过电流钳和电压钳记录对该制备中的面神经运动神经元的一些电生理和药理学特性进行的调查显示，与先前在体内观察到的成年运动神经元的特性非常相似（例如，时间依赖性内向整流、蜂毒明肽敏感的超极化后电位以及血清素诱导的缓慢去极化）。
