HIPPOCAMPAL 5-HT RECEPTORS AND CONSOLIDATION OF STRESSFUL MEMORIES
HIPPOCAMPAL 5-HT RECEPTORS AND CONSOLIDATION OF STRESSFUL MEMORIES
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DOI：
10.1016/0166-4328(93)90098-b
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发表时间：
1993-12-20
影响因子：
2.7
通讯作者：
DEALMEIDA, RT
中科院分区：
文献类型：
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作者：
GUIMARAES, FS;DELBEL, EA;DEALMEIDA, RT
已有研究表明，海马区突触后5-HT1a受体由位于中缝正中核的5-HT1a神经元支配，介导对厌恶事件的适应性或应对反应，该系统的功能障碍与抑郁症状有关。为了验证这一假设，我们研究了处于束缚应激状态下的动物c-fos基因的表达情况。结果表明，强迫束缚30min后，大鼠海马齿状回和CA1-CA3区c-fos基因表达显著增加，提示应激时该结构处于激活状态。为了研究海马区5-羟色胺神经传递在适应厌恶事件中的作用，我们将大鼠固定2小时，并在24小时后在高架的正迷宫中对它们进行测试。我们的结果表明，之前的限制时间减少了在迷宫中张开双臂的探索。这种作用可被束缚后立即向背侧海马区微量注射5-羟色胺再摄取阻断剂齐美定(20和100nmol)或5-HT1a激动剂8-OH-DPAT(3nmo1)所逆转。这些结果与位于海马区的突触后5-HT1a受体参与了对厌恶事件耐受性的发展这一观点是一致的。
It has been suggested that postsynaptic 5-HT1A receptors in the hippocampus, innervated by 5-HT neurons localized in the median raphe nucleus, mediate adaptive or coping responses to aversive events and that dysfunction of this system is related to symptoms of depression. To test this hypothesis we investigated the expression of c-fos mRNA in animals submitted to immobilization stress. The results showed that c-fos mRNA expression is significantly increased in the dentate gyrus and CA1-CA3 regions of the hippocampus after 30 min of forced restraint, suggesting that this structure is activated during stress. To investigate the role of 5-HT neurotransmission in the hippocampus on adaptation to aversive events we immobilized rats for 2 h and tested them 24 h later in an elevated plus-maze. Our results showed that the previous restraint period decreases exploration of open arms in the maze. This effect was reversed by bilateral microinjection of zimelidine (20 and 100 nmol), a 5-HT re-uptake blocker, or 8-OH-DPAT (3 nmol), a 5-HT1A agonist, into the dorsal hippocampus immediately after restraint. These results are compatible with the idea that postsynaptic 5-HT1A receptors located in the hippocampus participate in the development of tolerance to aversive events.