生理学报
生理學報
생이학보
ACTA PHYSIOLOGICA SINICA
2008年
2期
270-274
,共5页
长时程压抑%海马%NMDA受体%代谢型谷氨酸受体
長時程壓抑%海馬%NMDA受體%代謝型穀氨痠受體
장시정압억%해마%NMDA수체%대사형곡안산수체
long-term depression%hippocampus%N-methyl-D-aspartate receptors%metabotropic glutamate receptors
前期研究显示低频率多串刺激能够在成年大鼠海马CAl区诱发稳定的长时程压抑(long-term depression,LTD),而这种LTD的受体机制目前还不清楚.本研究采用成年大鼠海马脑片标本,电刺激Schaffer侧枝传入纤维,在CAl区锥体细胞层记录群体锋电位(population spikes,PS),并分别应用N-甲基-D-天冬氨酸(N-methyl-D-aspartate,NMDA)受体和代谢型谷氨酸(metabotropic glutamate,mGlu)受体的拮抗剂AP5和MCPG,观察两组低频率(2-Hz和5-Hz)多串刺激能否诱导LTD,以揭示不同刺激形式诱导成年大鼠LTD的可能受体机制.结果显示,AP5和MCPG都能抑制由2-Hz多串刺激诱导的LTD:强直刺激后20 min时PS幅度分别为基础值的(96.0±3.5)%(n=10)和(95.7±4.1)%(n=8).MCPG能够抑制5-Hz多串刺激诱导的LTD的产生,而AP5不能:分别应用AP5和MCPG后,强直刺激后35 min时PS的幅度分别为基础值的(73.6±4.4)%(n=10)和(98.2±8.9)%(n=8).以上结果提示,2-Hz多串刺激诱导的LTD可能依赖于NMDA受体与mGlu受体的共同活化,而5-Hz多串刺激诱导的LTD只与mGlu受体有关.因此,不同频率的多串刺激诱导的LTD涉及不同的谷氮酸受体机制.
前期研究顯示低頻率多串刺激能夠在成年大鼠海馬CAl區誘髮穩定的長時程壓抑(long-term depression,LTD),而這種LTD的受體機製目前還不清楚.本研究採用成年大鼠海馬腦片標本,電刺激Schaffer側枝傳入纖維,在CAl區錐體細胞層記錄群體鋒電位(population spikes,PS),併分彆應用N-甲基-D-天鼕氨痠(N-methyl-D-aspartate,NMDA)受體和代謝型穀氨痠(metabotropic glutamate,mGlu)受體的拮抗劑AP5和MCPG,觀察兩組低頻率(2-Hz和5-Hz)多串刺激能否誘導LTD,以揭示不同刺激形式誘導成年大鼠LTD的可能受體機製.結果顯示,AP5和MCPG都能抑製由2-Hz多串刺激誘導的LTD:彊直刺激後20 min時PS幅度分彆為基礎值的(96.0±3.5)%(n=10)和(95.7±4.1)%(n=8).MCPG能夠抑製5-Hz多串刺激誘導的LTD的產生,而AP5不能:分彆應用AP5和MCPG後,彊直刺激後35 min時PS的幅度分彆為基礎值的(73.6±4.4)%(n=10)和(98.2±8.9)%(n=8).以上結果提示,2-Hz多串刺激誘導的LTD可能依賴于NMDA受體與mGlu受體的共同活化,而5-Hz多串刺激誘導的LTD隻與mGlu受體有關.因此,不同頻率的多串刺激誘導的LTD涉及不同的穀氮痠受體機製.
전기연구현시저빈솔다천자격능구재성년대서해마CAl구유발은정적장시정압억(long-term depression,LTD),이저충LTD적수체궤제목전환불청초.본연구채용성년대서해마뇌편표본,전자격Schaffer측지전입섬유,재CAl구추체세포층기록군체봉전위(population spikes,PS),병분별응용N-갑기-D-천동안산(N-methyl-D-aspartate,NMDA)수체화대사형곡안산(metabotropic glutamate,mGlu)수체적길항제AP5화MCPG,관찰량조저빈솔(2-Hz화5-Hz)다천자격능부유도LTD,이게시불동자격형식유도성년대서LTD적가능수체궤제.결과현시,AP5화MCPG도능억제유2-Hz다천자격유도적LTD:강직자격후20 min시PS폭도분별위기출치적(96.0±3.5)%(n=10)화(95.7±4.1)%(n=8).MCPG능구억제5-Hz다천자격유도적LTD적산생,이AP5불능:분별응용AP5화MCPG후,강직자격후35 min시PS적폭도분별위기출치적(73.6±4.4)%(n=10)화(98.2±8.9)%(n=8).이상결과제시,2-Hz다천자격유도적LTD가능의뢰우NMDA수체여mGlu수체적공동활화,이5-Hz다천자격유도적LTD지여mGlu수체유관.인차,불동빈솔적다천자격유도적LTD섭급불동적곡담산수체궤제.
Previous reports suggested that a novel stimulus pattern of multi-train stimulus at low-frequency (2-Hz or 5-Hz) couldinduce stable long-term depression (LTD) in the CAl area of adult rat hippocampus. In the present study, in order to determine themechanism in LTD induced by the two novel tetanus patterns, changes in the population spikes (PS) in the hippocampal CAl area of adult rats following the multi-train stimulus in the presence of AP5 [antagonist of N-methyl-D-aspartate receptors (NMDARs)] orMCPG [antagonist of type Ⅰ/Ⅱ metabotropic glutamate receptors (mGluRs)] were recorded. The results showed that both AP5 andMCPG inhibited the LTD induced by 2-Hz multi-train stimulus. The mean amplitude of population spikes (PSA) normalized to thebaseline was (96.0±3.5)% after applying AP5 (n=10) and (95.7±4.1)% after applying MCPG (n=8), respectively, measured at 20 minpost-tetanus. While 5-Hz multi-train tetanus failed to induce LTD in the presence of MCPG. The mean PSA was (73.6±4.4)% (n=10)and (98.2±8.9)% (n=8) in the presence of AP5 and MCPG, respectively, measured at 35 min post-tetanus. So it is suggested that LTDinduced by 2-Hz multi-train tetanus involves co-activation of NMDARs and mGluRs, while LTD induced by 5-Hz multi-train tetanusis only related to activation of mGluRs.
