Johnston H M, Morris B J
Department of Pharmacology, University of Glasgow, U.K.
Neuroscience. 1994 Aug;61(3):435-9. doi: 10.1016/0306-4522(94)90423-5.
Application of N-methyl-D-aspartate on to the dendrites of hippocampal granule cells dramatically decreased prodynorphin messenger RNA levels in the affected cells while increasing proenkephalin messenger RNA levels. Sin-1 molsidomine (an agent which releases nitric oxide) and 8-bromo-cyclic GMP were similarly effective, and the actions of sin-1 molsidomine were blocked by inhibition of cyclic GMP-dependent protein kinase. Since, in this region, dynorphins act to inhibit potentiation of synaptic transmission, while enkephalins have excitatory effects, this switch in opioid gene expression is likely to have a prolonged effect on the efficiency of the mossy fibre synapses. In addition, the results demonstrate a powerful role for nitric oxide in the long-term regulation of hippocampal excitability.
将N-甲基-D-天冬氨酸应用于海马颗粒细胞的树突，会显著降低受影响细胞中前强啡肽信使核糖核酸水平，同时提高前脑啡肽信使核糖核酸水平。硝普钠（一种释放一氧化氮的药物）和8-溴环鸟苷酸也有类似效果，硝普钠的作用可被环鸟苷酸依赖性蛋白激酶的抑制所阻断。由于在该区域，强啡肽可抑制突触传递的增强，而脑啡肽具有兴奋作用，阿片样物质基因表达的这种转变可能会对苔藓纤维突触的效率产生长期影响。此外，研究结果表明一氧化氮在海马兴奋性的长期调节中发挥着重要作用。
