Nicola S M, Malenka R C
Department of Psychiatry, University of California, San Francisco, California, 94143-0984, USA.
J Neurophysiol. 1998 Apr;79(4):1768-76. doi: 10.1152/jn.1998.79.4.1768.
Although the ventral striatum (nucleus accumbens; NAc) and dorsal striatum are associated with different behaviors, these structures are anatomically and physiologically similar. In particular, dopaminergic afferents from the midbrain appear to be essential for the normal functioning of both nuclei. Although a number of studies have examined the effects of dopamine on the physiology of NAc or striatal cells, results have varied, and few studies have compared directly the actions of dopamine on both of these nuclei. Here we use slice preparations of the NAc and dorsal striatum to compare how synaptic transmission in these nuclei is modulated by catecholamines. As previously reported, dopamine depressed excitatory postsynaptic potentials (EPSPs) and inhibitory postsynaptic potentials (IPSPs) in the NAc. Surprisingly, however, neither EPSPs nor IPSPs in the dorsal striatum were affected by dopamine. Similarly, norepinephrine depressed excitatory synaptic transmission in the NAc by an alpha-adrenergic receptor-dependent mechanism but was without effect on excitatory transmission in the dorsal striatum. Inhibitory synaptic transmission was not affected by norepinephrine in either structure. These results suggest that the functional roles of dopamine and norepinephrine are not the same in the dorsal striatum and the NAc.
尽管腹侧纹状体（伏隔核；NAc）和背侧纹状体与不同行为相关，但这些结构在解剖学和生理学上是相似的。特别是，来自中脑的多巴胺能传入纤维似乎对这两个核的正常功能至关重要。虽然许多研究已经考察了多巴胺对NAc或纹状体细胞生理学的影响，但结果各不相同，而且很少有研究直接比较多巴胺对这两个核的作用。在这里，我们使用NAc和背侧纹状体的脑片标本，比较这些核中的突触传递是如何被儿茶酚胺调节的。如先前报道，多巴胺抑制了NAc中的兴奋性突触后电位（EPSP）和抑制性突触后电位（IPSP）。然而，令人惊讶的是，背侧纹状体中的EPSP和IPSP均未受到多巴胺的影响。同样，去甲肾上腺素通过α-肾上腺素能受体依赖性机制抑制了NAc中的兴奋性突触传递，但对背侧纹状体中的兴奋性传递没有影响。在这两个结构中，抑制性突触传递均未受到去甲肾上腺素的影响。这些结果表明，多巴胺和去甲肾上腺素在背侧纹状体和NAc中的功能作用并不相同。
