褪黑素对前额叶皮层锥体神经元兴奋性的影响及MT1R-cAMP-PKA信号通路在其中的作用  

Effects of melatonin on excitability of pyramidal neurons in prefrontal cortex and the role of MT1R-cAMP-PKA signaling pathway

作　　者：王进全 陈杨 张超 顾健腾 易斌 鲁开智 张铭 Wang Jinquan;Chen Yang;Zhang Chao;Gu Jianteng;Yi Bin;Lu Kaizhi;Zhang Ming(Department of Anesthesiology,First Affiliated Hospital,Military Medical University of the Army(Third Military Medical University),Chongqing 400038,China)

机构地区：[1]陆军军医大学(原第三军医大学)第一附属医院麻醉科,重庆400037

出　　处：《中华麻醉学杂志》2019年第2期221-223,共3页Chinese Journal of Anesthesiology

基　　金：国家自然科学基金(81600035).

摘　　要：目的评价褪黑素对前额叶皮层锥体神经元兴奋性的影响及褪黑素受体1-环磷酸腺苷-蛋白激酶A(MT1R-cAMP-PKA)信号通路在其中的作用。方法取出生14~21 d的雄性SD大鼠,取脑组织,制备厚约350μm的脑片,置于人工脑脊液中。采用随机数字表法,将脑片分为5组(n=6):对照组(C组)、褪黑素组(M组)、MT1/2R拮抗剂2-苯基-N-乙酰色胺+褪黑素组(L+M组)、MT2R拮抗剂4-苯基-2-丙酰胺曲胺+褪黑素组(P+M组)和PKA抑制剂腺苷-3,5-环状硫代磷酸三乙基铵盐+褪黑素组(R+M组)。C组细胞外灌流人工脑脊液2 min;M组细胞外灌流1μmol/L褪黑素2 min;L+M组细胞外灌流1μmol/L MT1/2R拮抗剂2-苯基-N-乙酰色胺和1μmol/L褪黑素的混合液2 min;P+M组细胞外灌流1μmol/L MT2R拮抗剂4-苯基-2-丙酰胺曲胺和1μmol/L褪黑素的混合液2 min;R+M组电极内液持续给予1 mmol/L PKA抑制剂腺苷-3,5-环状硫代磷酸三乙基铵盐,细胞外灌流1μmol/L褪黑素2 min。采用全细胞膜片钳技术,记录前额叶锥体神经元膜电位和钳制电流。结果与C组比较,M组钳制电流升高,膜电位降低(P<0.05);与M组比较,L+M组和R+M组钳制电流降低,膜电位升高(P<0.05),P+M组钳制电流和膜电位差异无统计学意义(P>0.05)。结论褪黑素可抑制前额叶皮层锥体神经元兴奋性,其机制与激活MT1R-cAMP-PKA信号通路有关。Objective To evaluate the effects of melatonin on the excitability of pyramidal neurons in the prefrontal cortex and the role of melatonin receptor 1(MT1R)-cyclic adenosine monophosphate(cAMP)-protein kinase A(PKA)signaling pathway.Methods Brains were obtained from male Sprague-Dawley rats between 14 and 21 days after birth.The brain slices of 350-μm thick were prepared and placed in artificial cerebrospinal fluid.The brain slices were divided into 5 groups(n=6 each)using a random number table method:control group(C group),melatonin group(M group),MT1/2R antagonist luzindole plus melatonin group(L+M group),MT2R antagonist 4P-PDOT plus melatonin group(P+M group)and PKA inhibitor Rp-cAMPS plus melatonin group(R+M group).Cells were perfused for 2 min with artificial cerebrospinal fluid in group C.Cells were perfused for 2 min with 1μmol/L melatonin in group M.Cells were perfused for 2 min with the mixture of 1μmol/L MT1/2R antagonist luzindole and 1μmol/L melatonin in group L+M.Cells were perfused for 2 min with the mixture of 1μmol/L MT2R antagonist 4P-PDOT and 1μmol/L melatonin in group P+M.In group R+M,1 mmol/L PKA inhibitor Rp-cAMPS was continuously added to the pipette solution,and cells were perfused for 2 min with 1μmol/L melatonin.The whole-cell patch-clamp technique was used to record the membrane potential and clamp current of pyramidal neurons in the prefrontal cortex.Results Compared with group C,the clamp current was significantly increased,and the membrane potential was decreased in group M(P<0.05).Compared with group M,the clamp current was significantly decreased,and the membrane potential was increased in L+M and R+M groups(P<0.05),and no significant change was found in the clamp current or membrane potential in group P+M(P>0.05).Conclusion Melatonin inhibits the excitability of pyramidal neutrons in the prefrontal cortex,and the mechanism is related to activating MT1R-cAMP-PKA signaling pathway.

关 键 词：褪黑激素 神经元 受体 褪黑激素 MT1 环AMP 蛋白激酶类 

分 类 号：R338[医药卫生—人体生理学]