摘要
目的 探讨慢性应激对大鼠海马长时程增强 (LTP)和氨基酸类神经递质的影响 ,以及苯妥英钠对LTP和氨基酸神经递质改变的效应。方法 将 2 4只SD雄性大鼠随机分为对照组、应激 +生理盐水 (10ml/kg)组和应激 +苯妥英钠 (40mg/kg)组 ,每组 8只。采用离体海马脑片结合电生理的方法观测海马CA1区LTP的变化。以群体峰电位 (PS)的幅值和场兴奋性突触后电位 (fEPSP)的斜率作为观察LTP变化的指标。应用高效液相色谱 紫外检测法检测海马氨基酸类神经递质的含量。结果 (1)应激 +生理盐水组PS幅值和fEPSP斜率在高频串刺激后增大的幅度低于对照组和应激 +苯妥英钠组 (P <0 0 5 )。 (2 )应激 +生理盐水组和应激 +苯妥英钠组的天冬氨酸含量 [分别为(4 74 6± 0 6 0 9) μmol/g和 (4 94 8± 0 75 1) μmol/g]高于对照组 [(2 4 2 5± 0 2 11) μmol/g ,P <0 0 1];应激 +生理盐水组的谷氨酸含量 [(8 0 94± 1 0 35 ) μmol/g]高于对照组 [(6 0 16± 0 6 77) μmol/g]和应激 +苯妥英钠组 [(6 970± 0 6 4 7) μmol/g];P <0 0 5 ;应激 +苯妥英钠组的γ 氨基丁酸 (GABA)含量[(5 14 2± 0 6 6 2 ) μmol/g]高于对照组 [(4 2 2 9± 0 4 4 9) μmol/g]和应激 +生理盐水组 [(4 2 4 9± 0 4 6 3)μmol/g],P <0
Objective To investigate the changes of long-term potentiation (LTP) and amino acid neurotransmitters in rat hippocampus induced by chronic stress and the effects of phenytoin (DPH) on them. Methods Twenty-four rats were randomly divided into control,stress-saline and stress-DPH groups,with eight in each. Saline (10 ml/kg) and phenytoin (40 mg/kg) were intraperitoneally injected daily before stress. Isolated hippocampal slice combining with electrophysiological technique was used to observe the changes of LTP in hippocampal CA1 field. Population spike (PS) amplitude and field excitatory postsynaptic potential (fEPSP) slope were used to indicate the LTP changes. High performance liquid chromatography coupled with UV detection was used for quantification of hippocampal amino acids neurotransmitters. Results The increases of PS amplitude and fEPSP slope after high-frequency stimulation in stress-saline group were significantly lower than those in both control and stress-DPH groups ( P<0.05). The levels of aspartate were significantly higher in stress-saline [(4.746±0.609)μmol/g] and stress-DPH [(4.948±0.751)μmol/g] groups than that in control group [(2.425±0.211)μmol/g; P<0.01],glutamate higher in stress-saline group [(8.094±1.035)μmol/g] than those in control [(6.016±0.677)μmol/g] and stress-DPH [(6.970±0.647) μmol/g] groups ( P<0.05),and γ-aminobutyric acid (GABA) higher in stress-DPH group [(5.142±0.662) μmol/g] than those in control [(4.229±0.449)μmol/g] and stress-saline [(4.249±0.463)μmol/g] groups ( P<0.01). Conclusions It is suggested that chronic stress can suppress the development of LTP in hippocampal CA1 field and increase the levels of hippocampal aspartate and glutamate,but not the level of GABA. DPH may keep LTP normal in stressed hippocampus,which may be involved in reducing glutamate and increasing GABA.
出处
《中华精神科杂志》
CAS
CSCD
北大核心
2004年第1期41-44,共4页
Chinese Journal of Psychiatry
