Quigg M, Straume M, Smith T, Menaker M, Bertram E H
Comprehensive Epilepsy Program, Department of Neurology, University of Virginia, Box 394, Health Sciences Center, Charlottesville, VA 22908, USA.
Brain Res. 2001 Sep 21;913(2):165-9. doi: 10.1016/s0006-8993(01)02780-9.
Epileptic seizures may alter neuroendocrinological cycles. Light pulses induce phase shifts in circadian rhythms. Using hippocampal-kindled rats to ensure maximal clinical expression, we determined if seizures likewise induce phase shifts.
We monitored the circadian rhythm of temperature (CRT) with intraperitoneal radiotelemetry in rats (n=21) isolated from time cues and light for 3-week trials. Seizures were triggered with hippocampal electrical stimulation at different circadian phases. Optimized, least-error phase shifts were calculated from preictal and postictal CRTs. Induced seizures were referenced to CRT (t(max)=00:00, 24-h circadian cycle).
Phase shifts (individual responses=57) differed across the circadian cycle. Rather than forming a clear phase-response curve, phase shifts were especially variable between 00:00 and 06:00 h.
This study demonstrates that electrically-induced seizures induce advances and delays in CRT in a phase-dependent fashion but in a pattern different from typical light-induced phase shifts. Disorders of circadian regulation may contribute to some of the altered endogenous cycles associated with epilepsy.
癫痫发作可能会改变神经内分泌周期。光脉冲会引起昼夜节律的相位偏移。我们利用海马体点燃大鼠以确保最大程度的临床症状表现，来确定癫痫发作是否同样会引起相位偏移。
我们通过腹腔内无线电遥测技术监测了21只大鼠的体温昼夜节律（CRT），这些大鼠在为期3周的试验中与时间线索和光线隔绝。在不同的昼夜阶段通过海马体电刺激引发癫痫发作。根据发作前和发作后的CRT计算出优化的、误差最小的相位偏移。将诱发的癫痫发作与CRT（t(max)=00:00，24小时昼夜周期）进行对照。
相位偏移（个体反应=57）在昼夜周期中有所不同。相位偏移并非形成一条清晰的相位反应曲线，而是在00:00至06:00之间变化尤为明显。
本研究表明，电诱发的癫痫发作会以相位依赖的方式引起CRT的提前和延迟，但模式不同于典型的光诱导相位偏移。昼夜节律调节紊乱可能是癫痫相关的一些内源性周期改变的原因之一。
