Sanford Larry D, Parris Brian, Tang Xiangdong
Sleep Research Laboratory, Department of Pathology and Anatomy, Eastern Virginia Medical School, PO Box 1980, Norfolk, VA 23501, USA.
Brain Res. 2002 Nov 29;956(2):276-84. doi: 10.1016/s0006-8993(02)03552-7.
It is becoming established that the amygdala has a strong influence on arousal state, with most evidence indicating a role in the regulation of rapid eye movement sleep (REM). Electrically activating the central nucleus of the amygdala (CNA) can increase subsequent REM and enhance REM-related phenomena. However, drugs that may be inhibitory to CNA have been typically reported to reduce REM. This suggests that enhancing activity in CNA could promote REM, and that inhibiting activity in CNA could suppress REM. We reversibly inactivated CNA using the GABA(A) agonist, muscimol, or blocked GABAergic inhibition with the GABA(A) antagonist, bicuculline, and examined the effects on sleep and wakefulness. Rats (90-day-old male Sprague-Dawley) were implanted with electrodes for recording EEG and EMG. Cannulae were aimed into CNA for microinjecting muscimol (0.001, 0.3 and 1.0 microM/0.2 microl saline) or bicuculline (56 and 333 pM/0.2 microl saline). Each animal received bilateral microinjections of muscimol, bicuculine or saline alone followed by 6-h sleep recordings. Microinjections of low concentrations of muscimol into CNA produced relatively selective decreases in total REM and number of REM episodes that lasted up to 6 h. In contrast, microinjections of bicuculline into CNA produced significant increases in REM. There were no significant reductions in NREM or wakefulness. These findings demonstrate that inactivating CNA can produce a relatively selective suppression of REM. The possible role that spontaneous activity in CNA may play in REM initiation and/or maintenance is discussed.
杏仁核已被证实对觉醒状态有强烈影响，大多数证据表明其在快速眼动睡眠（REM）调节中发挥作用。电刺激杏仁核中央核（CNA）可增加随后的REM并增强与REM相关的现象。然而，通常报道可能抑制CNA的药物会减少REM。这表明增强CNA的活性可促进REM，而抑制CNA的活性可抑制REM。我们使用GABA(A)激动剂蝇蕈醇可逆性地使CNA失活，或用GABA(A)拮抗剂荷包牡丹碱阻断GABA能抑制，并研究其对睡眠和觉醒的影响。将大鼠（90日龄雄性Sprague-Dawley大鼠）植入电极以记录脑电图（EEG）和肌电图（EMG）。将套管对准CNA，用于微量注射蝇蕈醇（0.001、0.3和1.0 microM/0.2微升生理盐水）或荷包牡丹碱（56和333 pM/0.2微升生理盐水）。每只动物接受双侧微量注射蝇蕈醇、荷包牡丹碱或单独的生理盐水，随后进行6小时的睡眠记录。向CNA微量注射低浓度的蝇蕈醇会使总REM和持续长达6小时的REM发作次数相对选择性减少。相比之下，向CNA微量注射荷包牡丹碱会使REM显著增加。非快速眼动睡眠（NREM）或觉醒没有显著减少。这些发现表明，使CNA失活可产生相对选择性的REM抑制。文中讨论了CNA中的自发活动在REM起始和/或维持中可能发挥的作用。
