Wan R Q, Wiegant V M, de Jong W, de Wied D
Rudolf Magnus Institute for Neurosciences, Department of Medical Pharmacology, Utrecht, The Netherlands.
Psychoneuroendocrinology. 1996 Aug;21(6):503-13. doi: 10.1016/s0306-4530(96)00013-3.
The central opioid system may have an important influence on memory processes. In view of this, the concentration of beta-endorphin-like immunoreactivity (beta-ELIR) in cerebrospinal fluid (CSF) was measured by a radioimmunoassay in rats trained in a passive avoidance procedure. The beta-ELIR in CSF was examined immediately, 2, 5, 10, and 30 min after the learning trial in which rats were exposed to footshock (0, 0.25, or 1.0 mA for 3 s). Avoidance latency and beta-ELIR in CSF were examined 24 and 120 h after the learning trial. The beta-ELIR in CSF was increased at 5 min after the learning trial in rats exposed to footshock of 0.25 mA. The beta-ELIR in CSF was elevated at 5 and 10 min, followed by a significant decrease at 30 min after the learning trial in rats exposed to a footshock of 1.0 mA. Thus, although an increase in beta-ELIR in CSF was not, the duration of the increase was, related to the shock intensity. Interestingly, a decrease followed the increase in beta-ELIR in CSF which was significant only in rats exposed to the high shock intensity. Avoidance latencies were enhanced in a shock intensity-dependent manner at both 24 and 120 h retention tests. No change in beta-ELIR in CSF was found during retention trials. The results suggest that behavioral manipulations alter beta-ELIR in CSF. An increase in beta-ELIR in CSF may be highly associated with stressful and emotional responses during behavioral training.
中枢阿片系统可能对记忆过程产生重要影响。鉴于此，采用放射免疫分析法测定了被动回避程序训练大鼠脑脊液（CSF）中β-内啡肽样免疫反应性（β-ELIR）的浓度。在大鼠接受足部电击（0、0.25或1.0 mA，持续3秒）的学习试验后，立即、2、5、10和30分钟检测CSF中的β-ELIR。在学习试验后24小时和120小时检测回避潜伏期和CSF中的β-ELIR。接受0.25 mA足部电击的大鼠在学习试验后5分钟时，CSF中的β-ELIR升高。接受1.0 mA足部电击的大鼠在学习试验后5分钟和10分钟时，CSF中的β-ELIR升高，随后在30分钟时显著下降。因此，虽然CSF中β-ELIR的增加与电击强度无关，但增加的持续时间与电击强度有关。有趣的是，CSF中β-ELIR升高后会出现下降，这仅在接受高电击强度的大鼠中显著。在24小时和120小时的保持测试中，回避潜伏期以电击强度依赖的方式延长。在保持试验期间，未发现CSF中β-ELIR有变化。结果表明，行为操作会改变CSF中的β-ELIR。CSF中β-ELIR的增加可能与行为训练期间的应激和情绪反应高度相关。
