Monoamine depletion alters the entrainment and the response to light of the circadian activity rhythm in hamsters.
Monoamine depletion alters the entrainment and the response to light of the circadian activity rhythm in hamsters.
复制标题
单胺消耗会改变仓鼠昼夜节律活动的夹带和对光的反应。
DOI：
10.1016/0006-8993(93)91656-d
复制
发表时间：
1993
期刊：
影响因子：
2.9
通讯作者：
Zee,PC
中科院分区：
文献类型：
--
作者：
Penev,PD;Turek,FW;Zee,PC
在啮齿类动物中，振幅降低、自由运行周期缩短和许多昼夜节律的不同步与老年有关。在衰老过程中，仓鼠昼夜节律系统对光刺激的反应也发生了改变。减少单胺水平，受体位置和神经元群是普遍观察到老化的大脑。本研究的目的是确定利血平对幼鼠单胺的消耗是否会引起运动活动昼夜节律的变化，类似于随着年龄的增长而自发发生的变化。连续监测12只幼鼠在14 h光照/10 h黑暗循环下的轮跑活动。在车辆治疗后1周和利血平（4mg /kg）治疗后3个1周期间，测定总活性水平、活性发作次数、峰值和抵消以及活性持续时间。第二组8只利血平治疗动物和6只载药治疗动物被置于持续黑暗（DD）中。测定对照组和利血平组DD的昼夜节律周期和短光脉冲在昼夜节律时间19 （CT19）后的相移。采用高压液相色谱法测定利血平和载药后下丘脑、纹状体和脑桥/髓质的单胺含量。采用χ2周期图、单因素方差分析及Duncan事后检验对数据进行分析。利血平治疗显著降低了总轮跑活动和下丘脑、纹状体和脑桥/髓质的单胺水平。利血平给药后携带活性的发作和峰值相对于光/暗（LD）周期更早；活动偏移延迟，活动阶段持续时间延长。利血平治疗后，DD运动活动的昼夜节律持续存在，振幅降低，自由运行周期延长，CT19响应光脉冲的相位推进显著增强。利血平治疗后运动活动昼夜节律的变化模式与老年动物观察到的相似。我们的研究结果提出了一种可能性，即昼夜节律系统中与年龄相关的改变可能与单胺能神经传递的缺陷有关。
Reduced amplitude, shorter free-running periods and desynchronization among a number of circadian rhythms are associated with advanced age in rodents. The response of the hamster circadian system to photic stimuli is also altered during senescence. Decreased monoamine levels, receptor sites and neuronal populations are commonly obsered in the aging brain. The objective of the present study was to determine if monoamine depletion with reserpine in young hamster induces changes in the circadian rhythm of locomotor activity similar to those that occur spontaneously with aging. Wheel-running activity of 12 young hamsters under a 14 h-light/10 h-dark cycle was continuously monitored. The total activity level, the times of activity onset, peak and offset and the duration of activity were determined during a 1-week period after vehicle treatment and for three 1-week periods after reserpine treatment (4 mg/kg). A second group of eight reserpine-treated and six vehicle-treated animals was kept in constant darkness (DD). The period of the circadian activity rhythm in DD and the phase-shifts after short light pulses at circadian time 19 (CT19) were determined in the control and reserpine-treated groups. Brain monoamines in the hypothalamus, striatum and pons/medulla after reserpine and vehicle treatment were determined by high-pressure liquid chromatography. The data were analyzed withχ2periodogram and one-way ANOVA followed by Duncan's post hoc test. Reserpine treatment significantly reduced total wheel-running activity and the monoamine levels in the hypothalamus, striatum and pons/medulla. The onset and peak of entrained activity after reserpine occurred earlier relative to the light/dark (LD) cycle; the offset of activity was delayed and the duration of the activity phase was prolonged. The circadian rhythm of locomotor activity in DD after reserpine treatment persisted with reduced amplitude and longer free-running period and the phase advances in response to light pulses at CT19 were dramatically augmented. The pattern of changes in the circadian rhythm of locomotor activity after reserpine treatment resembles that observed in old animals. Our results raise the possibility that the age-related alterations in the circadian system might be associated with deficits in the monoaminergic neurotransmission.