Effects of aging on the actions of general anesthetics in hippocampal slice

我们比较了4周龄（年轻组）和18周龄（老年组）时全身麻醉药对海马脑片CA1区作用的年龄相关性改变。从雄性Wistar大鼠制备横向海马切片（400 μm）。将两组双极电极分别置于Schaffer侧支纤维上，在CA1区[Sch]诱发群体锋电位（PS），并在肺泡上诱发抑制性中间神经元[Alv]诱发GABA能调制。挥发性麻醉剂（异氟烷、七氟烷）降低PS[Sch]，而静脉麻醉剂（硫喷妥钠、丙泊酚）对PS[Sch]的影响极小。挥发性麻醉药的抑制作用程度在年轻组和老年组之间相似。另一方面，挥发性和静脉麻醉剂均降低PS[Sch+Alv]。年轻组的行为比老年组更强烈。结论。我们证明了全身麻醉药的年龄依赖性修改。在离体大鼠中枢神经系统中，对抑制性突触传递有作用，但对兴奋性突触传递无作用。

We compared age-related modifications of the effects of general anesthetics in area CA1 of hippocampal slices at 4 weeks (younger group) and 18 weeks (elder group) of age.Method. Transverse hippocampal slices (400 μm) were prepared from male Wistar rats. Two sets of bipolar electrodes were placed on Schaffer collateral fibers to elicit population spikes (PS) in area CA1 [Sch], and on alveus hippocampi to activate the inhibitory interneurons for GABAergic modulation [Alv].Results. Volatile anesthetics (isoflurane, sevoflurane) decreased PS[Sch], while intravenous anesthetics (thiopental, propofol) had a minimal effects on PS[Sch]. The extents of inhibitory effects by volatile anesthetics were similar between younger and elder groups. On the other hand, both volatile and intravenous anesthetics reduced PS[Sch+Alv]. The actions were grater on younger group than on elder group.Conclusion. We demonstrated the age-dependent modification of general anesthetic. actions on the inhibitory synaptic transmission, but not on the excitatory synaptic transmission, in rat CNS preparations in vitro.