Role of NMDA receptor in neuroendocrine responses to emotional stress.

条件性恐惧刺激抑制后叶加压素的分泌，促进脑下垂体分泌催产素或催乳素，并抑制运动活动。为了确定在情绪记忆的回忆过程中激活的NMDA受体在大脑中的位置，我们在雄性大鼠身上检查了NMDA受体拮抗剂MK-801是否在条件性恐惧刺激阻止条件性恐惧反应的表达之前，在大脑的局部区域注入MK-801。对照组注入生理盐水。破坏杏仁核：对大鼠进行足部电击训练。第二天，在麻醉下，一种名为NMDA的神经毒素被注入双侧杏仁核。手术后一周，对大鼠进行条件性恐惧刺激测试。结论：1.NMDA组大鼠的神经内分泌和行为恐惧反应受损。杏仁核MK-801：在注入NMDA或生理盐水的大鼠中，神经内分泌和对条件性恐惧刺激的行为反应没有被阻断。孤束核MK-801：在条件恐惧刺激前30min给予MK-801的大鼠，VP反应受损，而OT、PRL和运动活动反应无明显变化。因此，NTS中的NMDA受体可能不是回忆过程或情绪记忆所必需的。MK-801在终纹床核(BNST)：在注射拮抗剂而不注射生理盐水的大鼠，恐惧刺激后VP和PRL反应明显受损，运动抑制明显减少。结果表明，BNST中的NMDA受体在情绪记忆的回忆中起着重要作用。

Conditioned fear stimuli inhibit secretion of vasopressin, facilitate secretion of oxytocin or prolactin by the pituitary and suppress motor activity. To identify the locations of the NMDA receptors in the brain that are activated during recall process of emotional memory, we examined in male rats whether an NMDA receptor antagonist, MK-801 infused in the localised areas of the brain 30 mm before conditioned fear stimuli blocks expression of conditioned fear responses. Physiological saline was infused in the control groups.1. Destruction of the amygdala: Rats were trained with electric foot shocks. On the next day, a neurotoxin, NMDA was infused in to the amygdala bilaterally under anaesthesia. One week after the surgery, rats were tested with conditioned fear stimuli. Neuroendocrine and behavioural fear responses were impaired in the NMDA groups.2. MK-801 in the amygdala: The neuroendocrine and behavioural responses to conditioned fear stimuli were not blocked in the NMDA- or Saline infused rats.3. MK-801 in the nucleus of tractus solitarius (NTS): In the rats infused with MK-801 30 min before conditioned fear stimuli, VP but not OT, PRL or motor activity response was impaired. Thus the NMDA receptor in the NTS could not be essential for the recall process or emotional memory.4. MK-801 in the bed nucleus of the stria terminalis (BNST): In the antagonist- but not saline-injected rats, VP and PRL responses were impaired and motor inhibition was reduced after fear stimuli, significantly. The results suggest that NMDA receptors in the BNST play a significant role in recall of emotional memory.