Doucet E, Pohl M, Fattaccini C M, Adrien J, Mestikawy S E, Hamon M
INSERM U288, Faculté de Médecine Pitié-Salpêtrière, Paris, France.
Synapse. 1995 Jan;19(1):18-28. doi: 10.1002/syn.890190104.
The regional distribution of the mRNA encoding the serotonin 5-HT1B receptor was studied in the central nervous system of the rat by in situ hybridization histochemistry and Northern blot analysis. A 180 base pair probe, corresponding to a highly selective portion of the third intracellular loop of the rat 5-HT1B receptor, was used. In most regions, a single 5 kb message was found by Northern blot analysis. However, two additional bands (2.5 and 4 kb) were detected in the striatum. The rank order of 5-HT1B mRNA abundance was striatum >> septum = ventral tegmentum > or = colliculi = hypothalamus = hippocampus > brain stem > or = cerebellum > or = dorsal horn of the spinal cord > cerebral cortex > or = ventral horn of the spinal cord > olfactory tubercle. This distribution was confirmed by in situ hybridization, which further revealed that the 5-HT1B mRNA was present in dorsal root ganglia, the layer IV of the cerebral cortex, the Purkinje cell layer of the cerebellum, the pyramidal neurons in the CA1 area of the hippocampus, and the dorsal and median raphe nuclei. In situ hybridization was also performed in nomifensine (10 mg/kg/i.p.)-pretreated rats whose serotoninergic neurons were extensively and selectively lesioned by microinjection of 5,7-dihydroxytryptamine (8 micrograms/1 microliter) directly into the anteroventral vicinity of anterior raphe nuclei 3 weeks before sacrifice. In lesioned rats, 5-HT1B mRNA was present in the same areas and at the same levels as in control rats, except in the dorsal and median raphe nuclei, where a marked decrease (-75%) in its local concentration was observed. These data provide the first demonstration of the synthesis of 5-HT1B receptor within serotoninergic neurons, as expected of their presynaptic autoreceptor function at the level of serotoninergic terminals.
通过原位杂交组织化学和Northern印迹分析，研究了大鼠中枢神经系统中编码5-羟色胺5-HT1B受体的mRNA的区域分布。使用了一个180碱基对的探针，其对应于大鼠5-HT1B受体第三细胞内环的高度选择性部分。通过Northern印迹分析，在大多数区域发现了一条单一的5kb信息。然而，在纹状体中检测到另外两条带（2.5kb和4kb）。5-HT1B mRNA丰度的顺序为：纹状体>>隔区 = 腹侧被盖区≥丘 = 下丘脑 = 海马体>脑干≥小脑≥脊髓背角>大脑皮层≥脊髓腹角>嗅结节。原位杂交证实了这种分布，其进一步揭示5-HT1B mRNA存在于背根神经节、大脑皮层IV层、小脑浦肯野细胞层、海马体CA1区的锥体细胞以及背侧和中缝核。还对诺米芬辛（10mg/kg/腹腔注射）预处理的大鼠进行了原位杂交，这些大鼠的5-羟色胺能神经元在处死前3周通过将5,7-二羟基色胺（8μg/1μl）直接微量注射到中缝前核的前腹侧附近而被广泛且选择性地损伤。在损伤的大鼠中，5-HT1B mRNA存在于与对照大鼠相同的区域且水平相同，但在背侧和中缝核中，其局部浓度显著降低（-75%）。这些数据首次证明了5-HT1B受体在5-羟色胺能神经元内的合成，这与其在5-羟色胺能终末水平的突触前自身受体功能相符。
