Yuksel Cagri, Watford Lauren, Muranaka Monami, Daffre Carolina, McCoy Emma, Lax Hannah, Mendelsohn Augustus Kram, Oliver Katelyn I, Acosta Alexis, Vidrin Abegail, Martinez Uriel, Lasko Natasha, Orr Scott, Pace-Schott Edward F
Schizophrenia and Bipolar Disorder Program, McLean Hospital, Belmont, MA, USA.
Department of Psychiatry, Harvard Medical School, Boston, MA, USA.
Psychol Med. 2024 Dec 9;54(16):1-12. doi: 10.1017/S0033291724002757.
Accumulating evidence suggests that rapid eye movement sleep (REM) supports the consolidation of extinction memory. REM is disrupted in posttraumatic stress disorder (PTSD), and REM abnormalities after traumatic events increase the risk of developing PTSD. Therefore, it was hypothesized that abnormal REM in trauma-exposed individuals may pave the way for PTSD by interfering with the processing of extinction memory. In addition, PTSD patients display reduced vagal activity. Vagal activity contributes to the strengthening of memories, including fear extinction memory, and recent studies show that the role of vagus in memory processing extends to memory consolidation during sleep. Therefore, it is plausible that reduced vagal activity during sleep in trauma-exposed individuals may be an additional mechanism that impairs extinction memory consolidation. However, to date, the contribution of sleep vagal activity to the consolidation of extinction memory or any emotional memory has not been investigated.
Trauma-exposed individuals ( = 113) underwent a 2-day fear conditioning and extinction protocol. Conditioning and extinction learning phases were followed by extinction recall 24 h later. The association of extinction recall with REM characteristics and REM vagal activity (indexed as heart rate variability) during the intervening consolidation night was examined.
Consistent with our hypotheses, REM disruption was associated with poorer physiological and explicit extinction memory. Furthermore, higher vagal activity during REM was associated with better explicit extinction memory, and physiological extinction memory in males.
These findings support the notion that abnormal REM, including reduced REM vagal activity, may contribute to PTSD by impairing the consolidation of extinction memory.
越来越多的证据表明，快速眼动睡眠（REM）有助于消退记忆的巩固。创伤后应激障碍（PTSD）患者的快速眼动睡眠受到干扰，创伤事件后的快速眼动睡眠异常会增加患PTSD的风险。因此，有人推测，经历创伤的个体出现的异常快速眼动睡眠可能会通过干扰消退记忆的处理为PTSD的发生铺平道路。此外，PTSD患者的迷走神经活动降低。迷走神经活动有助于加强记忆，包括恐惧消退记忆，最近的研究表明，迷走神经在记忆处理中的作用延伸到睡眠期间的记忆巩固。因此，经历创伤的个体在睡眠期间迷走神经活动降低可能是损害消退记忆巩固的另一种机制，这似乎是合理的。然而，迄今为止，睡眠迷走神经活动对消退记忆或任何情绪记忆巩固的作用尚未得到研究。
113名经历创伤的个体接受了为期2天的恐惧条件反射和消退实验方案。在条件反射和消退学习阶段之后，24小时后进行消退回忆。研究了在中间的巩固夜间，消退回忆与快速眼动睡眠特征和快速眼动睡眠迷走神经活动（以心率变异性为指标）之间的关联。
与我们的假设一致，快速眼动睡眠中断与较差的生理和显性消退记忆相关。此外，快速眼动睡眠期间较高的迷走神经活动与较好的显性消退记忆以及男性的生理消退记忆相关。
这些发现支持了这样一种观点，即包括快速眼动睡眠迷走神经活动降低在内的异常快速眼动睡眠可能通过损害消退记忆的巩固而导致PTSD。
