Uteshev V, Stevens D R, Haas H L
Department of Physiology, Heinrich-Heine Universität, Düsseldorf, Germany.
Neuroscience. 1995 May;66(1):143-9. doi: 10.1016/0306-4522(94)00593-t.
Histamine neurons acutely dissociated from the tuberomammillary nucleus of the rat hypothalamus were studied in whole-cell and cell-attached patch-clamp experiments. Electrophysiological properties of dissociated cells were found to be similar to those recorded in slice experiments using microelectrodes. Tuberomammillary neurons fired spontaneously and this activity persisted when Cs+ (1.5 mM) was added to, or when K+ was removed from the extracellular solution. In whole-cell experiments a persistent tetrodotoxin-sensitive inward current was recorded. In cell attached recordings voltage-gated sodium channels displayed either normal or non-inactivating behavior. These results provide a further analysis of the properties of histaminergic neurons and indicate that spontaneous activity is intrinsic to individual neurons. Evidence for a non-inactivating tetrodotoxin-sensitive sodium current is presented. Single channel recordings indicate that this current is the result of non-inactivating behavior of sodium channels. Such a current is well suited for biasing tuberomammillary neurons toward spontaneous activity.
在全细胞膜片钳和细胞贴附膜片钳实验中，对从大鼠下丘脑结节乳头体核急性分离出的组胺能神经元进行了研究。发现分离细胞的电生理特性与使用微电极在脑片实验中记录到的特性相似。结节乳头体神经元自发放电，当向细胞外溶液中添加1.5 mM Cs+或去除K+时，这种活动仍持续存在。在全细胞实验中记录到一种持续的河豚毒素敏感内向电流。在细胞贴附记录中，电压门控钠通道表现出正常或非失活行为。这些结果进一步分析了组胺能神经元的特性，并表明自发活动是单个神经元固有的。提出了存在非失活的河豚毒素敏感钠电流的证据。单通道记录表明，这种电流是钠通道非失活行为的结果。这种电流非常适合使结节乳头体神经元偏向自发活动。
