Anderson K D, Reiner A
Department of Anatomy and Neurobiology, University of Tennessee, Memphis 38163.
J Comp Neurol. 1991 Jan 22;303(4):658-73. doi: 10.1002/cne.903030410.
Two largely separate populations of neuropeptide-containing striatonigral projection neurons have been distinguished in pigeons, one population whose neurons contain substance P (SP) and dynorphin (DYN) and a second population whose neurons contain enkephalin (ENK) (Reiner, '86a; Anderson and Reiner, '90a). In the present study, we investigated the abundance of these two types of neurons relative to all striatonigral projection neurons by combining retrograde labeling by the fluorescent dye fluorogold with immunofluorescence labeling for SP and ENK. Pigeons received large intranigral injections of fluorogold to retrogradely label the striatonigral projection neurons, and several days later they were treated with colchicine (32 hours before transcardial perfusion). Adjacent series of sections through the basal ganglia were labeled for SP and ENK using immunofluorescence techniques. The tissue was examined using fluorescence microscopy and the percentages of retrogradely labeled neurons containing either SP or ENK were quantified. We found that 85-95% of the fluorogold-labeled striatonigral neurons were SP+, whereas only 1-4% were ENK+. Thus the majority of striatonigral projection neurons in pigeons appear to contain SP, whereas a small percentage contain ENK. Only a small percentage of striatonigral neurons did not contain either. Since striatal projection neurons also contain GABA (Reiner, '86b), the present results suggest that a high percentage of striatonigral projection neurons coexpress SP, DYN and GABA, whereas a small fraction coexpress ENK and GABA. The available data are consistent with the conclusion that this is true in reptilian and mammalian species as well.
在鸽子中已区分出两类在很大程度上相互独立的含神经肽的纹状体黑质投射神经元，一类神经元含有P物质（SP）和强啡肽（DYN），另一类神经元含有脑啡肽（ENK）（赖纳，1986年a；安德森和赖纳，1990年a）。在本研究中，我们通过将荧光染料荧光金的逆行标记与SP和ENK的免疫荧光标记相结合，研究了这两类神经元相对于所有纹状体黑质投射神经元的丰度。给鸽子进行大剂量黑质内注射荧光金，以逆行标记纹状体黑质投射神经元，几天后用秋水仙碱处理（经心灌注前32小时）。使用免疫荧光技术对穿过基底神经节的相邻系列切片进行SP和ENK标记。使用荧光显微镜检查组织，并对含有SP或ENK的逆行标记神经元的百分比进行量化。我们发现，85% - 95%的荧光金标记的纹状体黑质神经元为SP阳性，而只有1% - 4%为ENK阳性。因此，鸽子中大多数纹状体黑质投射神经元似乎含有SP，而一小部分含有ENK。只有一小部分纹状体黑质神经元既不含有SP也不含有ENK。由于纹状体投射神经元也含有γ-氨基丁酸（GABA）（赖纳，1986年b），目前的结果表明，高比例的纹状体黑质投射神经元共表达SP、DYN和GABA，而一小部分共表达ENK和GABA。现有数据与这一结论一致，即在爬行动物和哺乳动物物种中也是如此。
