大鼠杏仁皮质核内γ-氨基丁酸与一氧化氮共存神经元分布及对痛觉信息传递的调控

背景大鼠杏仁复合体分布有较多的还原型尼克酰胺腺嘌呤二核苷酸脱氢酶阳性神经元,γ-氨基丁酸也是广泛地存在于哺乳动物中枢神经系统的一种重要的抑制性神经递质,γ-氨基丁酸与一氧化氮合酶是否在大鼠杏仁复合体内共存目前尚不清楚.目的采用还原型尼克酰胺腺嘌呤二核苷酸脱氢酶组织化学和免疫组化双重染色相结合的方法,观察杏仁皮质核内是否存在γ-氨基丁酸与还原型尼克酰胺腺嘌呤二核苷酸脱氢酶共存的神经元.设计以实验动物为研究对象,验证性对照研究.单位两所大学的解剖教研室.材料实验于2004-05/06在浙江大学医学院解剖教研室完成.选择SD大鼠6只,雌雄不拘,体质量250～300 g.干预制备大鼠脑组织冠状连续冰冻切片,取4套切片分别用作尼氏染色、还原型尼克酰胺腺嘌呤二核苷酸脱氢酶组织化学、还原型尼克酰胺腺嘌呤二核苷酸脱氢酶组织化学和γ-氨基丁酸免疫组化双重染色以及检查抗体特异性的对照实验.计数杏仁皮质核核团内γ-氨基丁酸标记神经元数目、还原型尼克酰胺腺嘌呤二核苷酸脱氢酶阳性神经元数目以及还原型尼克酰胺腺嘌呤二核苷酸脱氢酶/y-氨基丁酸双标神经元的数目,计算出双标阳性神经元数占单标阳性神经元数的百分比.内氏染色用作核团定位.主要观察指标还原型尼克酰胺腺嘌呤二核苷酸脱氢酶和γ-氨基丁酸双标和单标神经元分布情况.结果显示γ-氨基丁酸阳性神经元多散在分布于杏仁皮质后内侧核、杏仁皮质后外侧核,以小型为主,中型较少,还原型尼克酰胺腺嘌呤二核苷酸脱氢酶阳性神经元多散在分布于杏仁皮质后内侧核、杏仁皮质后外侧核,杏仁皮质前核以中、小型神经元为主,双标神经元(γ-氨基丁酸/还原型尼克酰胺腺嘌呤二核苷酸脱氢酶均阳性)多散在分布于杏仁皮质后外侧核,以中、小型神经元为主.还原型尼克酰胺腺嘌呤二核苷酸脱氢酶和γ-氨基丁酸双标神经元与单标神经元的比例分别24.5%(γ-氨基丁酸),46.7%(还原型尼克酰胺腺嘌呤二核苷酸脱氢酶).结论大鼠杏仁皮质核内有γ-氨基丁酸与还原型尼克酰胺腺嘌呤二核苷酸脱氢酶共存的神经元,提示一氧化氮对杏仁皮质核内的γ-氨基丁酸能神经元可能有调控作用.

Distribution of gamma-aminobutyric and nitrogen monoxide-coexisting neurons in cortical amygdaloid nucleus in rats and its modulation effect on pain transmission

BACKGROUND: Quite a few deoxidized reduced form of nicotinamide-adenime dinucleotide phosphate (NADPH-d) -positive neurons distribute in amygdala complex (AMC) and gamma-aminobutyric acid(GABA)is an important inhibitory neurotransmitter that also widely distributes in the central nervous system (CNS) of mammals. Whether there is coexistence of GABA and nitricoxide synthase (NOS) in AMC is unknown at present.OBJECTIVE: To observe whether there is GABA and NADPH-d-eoexist neuron in cortical nucleus of amygdala (Co) with the combination of NADPH-d hischemical and immunohistochemical double staining.DESIGN: A verifying controlled study based on the experimental animals.SETTING: Department of anatomy of two universities MATERIALS: The study was conducted in the department of Anatomy,Medical College of Zhejiang University between May 2004 and June 2004. Six SD rats in either gender with a body mass between 250 g and 300 g were selected.INTERVENTIONS: Coronary serial frozen slices of brain tissue were prepared. 4 sets of slices were selected for Nissl staining, NADPH-d histochemical staining, NADPH-d histochemical and GABA immunohistochemical double staining, and control experiment for the test of antibody specificity. GABA-labeled neurons, NADPH-d-positive neurons, and NADPH-d/GABA double-labeled neurons were counted in Co nucleus for the calculation of the percentage of double-labeled positive neurons to single-labeled positive neurons.MAIN OUTCOME MEASURES: Distribution of NADPH-d/GABA double labeled neuron; distribution of NADPH-d or GABA single labeled neuron.RESULTS: Most of GABA-positive neurons distributed in posteromed cortical amygdaloid nucleus (PMCo), posterolateral cortical amygdaloid nucleus (PLCo), which were mainly small types but few middle types. Most of NADPH-d-positive neurons distributed in PMCo, PLCo and anterior cortical amygdaloid nucleus (Aco), which were mainly middle sized and small sized neurons. The ratio of NADPH-d/GABA double-labeled neurons to single labeled neuron was 24.5% (GABA) or 46.7% (NADPH-d).CONCLUSION: There is GABA/NADPH-d-coexist neuronsin Co of rats,which suggests NO might have modulative effect on GABA neuron in Co.