Objective To investigate whether environmental cues associated with different properties of morphine could regulate the extracellular levels of glutamate and y-aminobutyric acid （GABA） in the hippocampal ventral subiculum, which play a critical role in the reinstatement of drug-seeking behavior induced by environmental cues. Methods Conditioning place preference （CPP） and conditioning place aversion （CPA） models were used to establish environment associated with rewarding and aversive properties of morphine respectively. Microdialysis and high performance liquid chromatography were used to measure the extracelluar level of glutamate and GABA in the ventral subiculum under these environmental cues. Results Exposure to the environmental cues associated with rewarding properties of morphine resulted in a decrease （approximately 11%） of extracellular level of GABA in ventral subiculum, and exposure to the environmental cues associated with aversive properties of morphine resulted in an increase （approximately 230%） of extracellular level of glutamate in ventral subiculum. Conclusion Environmental cues associated with different properties of morphine modulate the release of distinct neurotransmitters in the hippocampal ventral subiculum possibly through different neural circuit.
目的:研究杏仁中央核(Central nucleus of the amygdala,CeA)N-甲基-D-天冬氨酸(N-methyl-D-aspartate,NMDA)受体在纳络酮诱发急性吗啡依赖大鼠戒断性情绪反应中的作用。方法:吗啡、纳络酮间隔4小时皮下注射,通过两轮纳络酮匹配训练建立条件性位置厌恶(Conditioned place aversion,CPA),作为急性吗啡依赖戒断诱发的情绪反应模型。观察纳络酮匹配训练前CeA微量注射NMDA受体拮抗剂地卓西平(MK801)对大鼠训练后在纳络酮匹配侧停留时间的影响。结果:戒断组大鼠经过两轮训练后在纳络酮匹配侧停留时间(230.4±32.8s)比假手术组(457.6±47.8s)显著缩短(P<0.01),训练前CeA微量注射MK801大鼠在纳络酮匹配侧停留时间(447.0±51.8s)比戒断组(230.4±32.8s)显著延长(P<0.01),非戒断组大鼠(急性吗啡依赖组,未接触吗啡组)训练前CeA注射MK801训练前后在处理侧停留时间差异无显著性(P>0.05)。结论:CeA注射MK801既无奖赏效应也无厌恶效应,但能阻断CPA的建立,提示CeA的NMDA受体参与急性吗啡依赖戒断诱发的情绪反应。
