Ouimet C C, Langley-Gullion K C, Greengard P
Program in Neuroscience, Biomedical Research Facility, Florida State University, Tallahassee, FL 32306, USA.
Brain Res. 1998 Oct 12;808(1):8-12. doi: 10.1016/s0006-8993(98)00724-0.
DARPP-32, a dopamine and cAMP-regulated phosphoprotein with an apparent molecular weight of 32 kD, is enriched in dopaminoceptive brain regions. Chief among these regions is the caudatoputamen which contains a large number of DARPP-32-containing medium sized spiny neurons. Since medium spiny neurons are a heterogeneous population with respect to connections and chemical neuroanatomy, it seemed of interest to determine whether DARPP-32 is present in all medium-sized neurons, or only within a specific subpopulation. The present study used immunocytochemistry and quantitative analysis to address this issue. We demonstrate that DARPP-32 is contained in almost all medium-sized neurons (96.4%) and is not detected in large neurons. Taken together with previous observations that the DARPP-32-containing medium-sized neurons project heavily to all neostriatal targets, these data demonstrate that DARPP-32 is present in virtually all neostriatal output neurons. Thus, the DARPP-32 cascade represents a final common pathway through which convergent afferent fibers using a variety of neurotransmitter agents may modulate striatal outflow.
多巴胺和环磷酸腺苷调节的磷蛋白（DARPP-32），表观分子量为32 kD，在多巴胺感受性脑区中含量丰富。其中主要区域是尾状核壳核，它含有大量表达DARPP-32的中等大小棘状神经元。由于中等大小棘状神经元在连接和化学神经解剖学方面是异质群体，因此确定DARPP-32是存在于所有中等大小神经元中，还是仅存在于特定亚群中似乎很有意义。本研究采用免疫细胞化学和定量分析来解决这个问题。我们证明，几乎所有中等大小神经元（96.4%）都含有DARPP-32，而在大神经元中未检测到。结合先前的观察结果，即含有DARPP-32的中等大小神经元大量投射到所有新纹状体靶区，这些数据表明，几乎所有新纹状体输出神经元中都存在DARPP-32。因此，DARPP-32级联反应代表了一条最终的共同通路，通过这条通路，使用多种神经递质的汇聚传入纤维可以调节纹状体的输出。
