Anderson K D, Reiner A
Department of Anatomy and Neurobiology, University of Tennessee Health Sciences Center, Memphis 38163.
J Comp Neurol. 1990 May 15;295(3):339-69. doi: 10.1002/cne.902950302.
A number of different neuroactive substances have been found in striatal projection neurons and in fibers and terminals in their target areas, including substance P (SP), enkephalin (ENK), and dynorphin (DYN). In a preliminary report on birds and reptiles, we have suggested that SP and DYN are to a large extent found in the same striatal projection neurons and that ENK is found in a separate population of striatal projection neurons. In the present study, we have examined this issue in more detail in pigeons and turtles. Further, we have also explored this issue in rats to determine whether this is a phylogenetically conserved feature of basal ganglia organization. Simultaneous immunofluorescence double-labeling procedures were employed to explore the colocalization of SP and DYN, SP and ENK, and ENK and DYN in striatal neurons and in striatal, nigral, and pallidal fibers in pigeons, turtles, and rats. To guard against possible cross-reactivity of DYN and ENK antisera with each others' antigens, separate double-label studies were carried out with several different antisera that were specific for DYN peptides (e.g., dynorphin A 1-17, dynorphin B, leumorphin) or ENK peptides (leucine-enkephalin, metenkephalin-arg6-gly7-leu8, methionine-enkephalin-arg6-phe7). The results showed that SP and DYN co-occur extensively in specific populations of striatal projection neurons, whereas ENK typically is present in different populations of striatal projection neurons. In pigeons, 95-99% of all striatal neurons containing DYN were found to contain SP and vice versa. In contrast, only 1-3% of the SP+ striatal neurons and no DYN neurons contained ENK. Similarly, in turtles, greater than 75% of the SP+ neurons were DYN+ and vice versa, whereas ENK was observed in fewer than 5% of the SP+ neurons and 2% of the DYN+ neurons. Finally, in rats, more than 70% of the SP+ neurons contained DYN and vice versa, but ENK was found in only 5% of the SP+ neurons and in none of the DYN+ perikarya. Fiber double-labeling in the striatum and its target areas (the pallidum and substantia nigra) was also consonant with these observations in pigeons, turtles, and rats. These results, in conjunction with studies in cats by M.-J. Besson, A.M. Graybiel, and B. Quinn (1986; Soc Neurosci. Abs. 12:876) strongly indicate that the co-occurrence of SP and DYN in large numbers of striatonigral and striatopallidal projection neurons in a phylogenetically widespread, and therefore evolutionarily conserved, feature of basal ganglia organization.(ABSTRACT TRUNCATED AT 400 WORDS)
在纹状体投射神经元及其靶区的纤维和终末中发现了多种不同的神经活性物质，包括P物质（SP）、脑啡肽（ENK）和强啡肽（DYN）。在一份关于鸟类和爬行动物的初步报告中，我们指出，在很大程度上，SP和DYN存在于同一群纹状体投射神经元中，而ENK则存在于另一群纹状体投射神经元中。在本研究中，我们在鸽子和乌龟中更详细地研究了这个问题。此外，我们还在大鼠中探讨了这个问题，以确定这是否是基底神经节组织在系统发育上保守的特征。采用同步免疫荧光双标记程序，研究鸽子、乌龟和大鼠纹状体神经元以及纹状体、黑质和苍白球纤维中SP与DYN、SP与ENK、ENK与DYN的共定位情况。为防止DYN和ENK抗血清与其各自抗原之间可能的交叉反应，使用几种对DYN肽（如强啡肽A 1-17、强啡肽B、亮啡肽）或ENK肽（亮氨酸脑啡肽、蛋氨酸脑啡肽-精氨酸6-甘氨酸7-亮氨酸8、蛋氨酸脑啡肽-精氨酸6-苯丙氨酸7）特异的不同抗血清进行了单独的双标记研究。结果表明，SP和DYN广泛共存在特定的纹状体投射神经元群中，而ENK通常存在于不同的纹状体投射神经元群中。在鸽子中，发现所有含DYN的纹状体神经元中有95-99%也含SP，反之亦然。相比之下，仅1-3%的SP+纹状体神经元含ENK，而含DYN的神经元中没有ENK。同样，在乌龟中，超过75%的SP+神经元是DYN+，反之亦然，而在不到5%的SP+神经元和2%的DYN+神经元中观察到ENK。最后，在大鼠中，超过70%的SP+神经元含DYN，反之亦然，但仅5%的SP+神经元含ENK，且所有DYN+胞体中均未发现ENK。纹状体及其靶区（苍白球和黑质）的纤维双标记结果也与鸽子、乌龟和大鼠的这些观察结果一致。这些结果，结合M.-J.贝松、A.M.格雷比尔和B.奎因（1986年；神经科学学会论文摘要12:876）对猫的研究，有力地表明，SP和DYN在大量纹状体黑质和纹状体苍白球投射神经元中共存是基底神经节组织在系统发育上广泛存在且因此在进化上保守的特征。（摘要截于400字）
