Ries C R, Puil E
Department of Pharmacology and Therapeutics, Faculty of Medicine, University of British Columbia, Vancouver, Canada.
Neurosci Lett. 1993 Sep 3;159(1-2):91-4. doi: 10.1016/0304-3940(93)90806-v.
We used patch-clamp whole-cell techniques to assess the effects of a volatile anaesthetic on thalamic firing modes in rat brain slices. Isoflurane application in clinical concentrations (0.5-2%) reversibly prevented voltage-dependent transitions to repetitive spike and burst firing modes in ventrobasal neurons. In voltage-clamp studies, isoflurane increased leak conductance, which shunted tonic and burst firing. Isoflurane also blocked the low-threshold Ca(2+)-current underlying the burst mode of firing, by increasing leak current and depressing membrane Ca(2+)-channel activity. We suggest that the mechanism of anaesthesia is distinct from sleep, although both states critically involve excitabilities of thalamic neurons.
我们采用膜片钳全细胞技术评估挥发性麻醉剂对大鼠脑片丘脑放电模式的影响。临床浓度（0.5 - 2%）的异氟烷可逆地阻止腹侧基底核神经元中电压依赖性向重复峰电位和爆发式放电模式的转变。在电压钳研究中，异氟烷增加了漏电导，从而分流了紧张性和爆发式放电。异氟烷还通过增加漏电流和抑制膜钙通道活性，阻断了爆发式放电模式下的低阈值钙电流。我们认为麻醉机制与睡眠不同，尽管这两种状态都与丘脑神经元的兴奋性密切相关。
