Marcel D, Weissmann D, Bardelay C, Meunier C, Pujol J F
Laboratoire de Neuropharmacologie, Faculté de Medecine Alexis Carrel, Lyon, France.
Brain Res Bull. 1987 Oct;19(4):485-94. doi: 10.1016/0361-9230(87)90153-5.
The distribution of benzodiazepine binding sites was analysed in the cingulate cortex of the rat brain by quantitative radioautography of brain sections incubated with a full agonist benzodiazepine ligand, 3H-flunitrazepam (3H-FLU), or with a partial agonist with non benzodiazepine structure, (7-3H)-4hydroxy-N(4,5-dihydroxy-2-thiazolyl)-6 methoxy-3-quinoline (3H-RU 43028), after lesion of noradrenaline (NA) and dopamine (DA) containing afferents to this structure. NA denervation was obtained by systemic administration of N-(2-chlorethyl)-N ethyl-2-bromobenzylamine (DSP4) and destruction of both NA and DA containing afferents was induced by unilateral injection of 6-hydroxydopamine (6-OHDA) in the middle forebrain bundle (MFB). A similar caudo-rostral pattern of distribution was found in the cingulate cortex after incubation with these two ligands which bound a greater number of sites in the anterior portion of the structure. In spite of a very precise anatomical sampling (200 micron intervals along the postero-anterior axis) no significant difference was observed when intact and lesioned brains were compared. It is concluded that benzodiazepine binding sites eventually localized on catecholaminergic afferents to the cingulate cortex do not represent a significant proportion of the total population of these sites in this structure.
在大鼠大脑扣带回皮质中，通过对用全激动剂苯二氮䓬配体3H-氟硝西泮（3H-FLU）或具有非苯二氮䓬结构的部分激动剂（7-3H）-4-羟基-N-（4,5-二羟基-2-噻唑基）-6-甲氧基-3-喹啉（3H-RU 43028）孵育的脑切片进行定量放射自显影，分析了苯二氮䓬结合位点的分布。在去甲肾上腺素（NA）和多巴胺（DA）传入该结构的神经纤维受损后进行上述操作。通过全身给予N-（2-氯乙基）-N-乙基-2-溴苄胺（DSP4）实现NA去神经支配，通过在中脑前束（MFB）单侧注射6-羟基多巴胺（6-OHDA）诱导同时破坏含NA和DA的传入神经纤维。在用这两种配体孵育后的扣带回皮质中发现了类似的尾-头分布模式，这两种配体在该结构前部结合的位点数量更多。尽管进行了非常精确的解剖取样（沿后-前轴以200微米间隔），但比较完整和受损大脑时未观察到显著差异。得出的结论是，最终定位于扣带回皮质儿茶酚胺能传入神经纤维上的苯二氮䓬结合位点在该结构中占这些位点总数的比例并不显著。
