Short-Term Total Sleep-Deprivation Impairs Contextual Fear Memory, and Contextual Fear-Conditioning Reduces REM Sleep in Moderately Anxious Swiss Mice

Abstract

The conditioning tasks have been widely used to model fear and anxiety and to study their association with sleep. Many reports suggest that sleep plays a vital role in the consolidation of fear memory. Studies have also demonstrated that fear-conditioning influences sleep differently in mice strains having a low or high anxiety level. It is, therefore, necessary to know, how sleep influences fear-conditioning and how fear-conditioning induces changes in sleep architecture in moderate anxious strains. We have used Swiss mice, a moderate anxious strain, to study the effects of: (i) sleep deprivation on contextual fear conditioned memory, and also (ii) contextual fear conditioning on sleep architecture. Animals were divided into three groups: (a) non-sleep deprived (NSD); (b) stress control (SC); and (c) sleep-deprived (SD) groups. The SD animals were SD for 5 h soon after training. We found that the NSD and SC animals showed 60.57% and 58.12% freezing on the testing day, while SD animals showed significantly less freezing (17.13% only; p < 0.001) on the testing day. Further, we observed that contextual fear-conditioning did not alter the total amount of wakefulness and non-rapid eye movement (NREM) sleep. REM sleep, however, significantly decreased in NSD and SC animals on the training and testing days. Interestingly, REM sleep did not decrease in the SD animals on the testing day. Our results suggest that short-term sleep deprivation impairs fear memory in moderate anxious mice. It also suggests that NREM sleep, but not REM sleep, may have an obligatory role in memory consolidation.

Hippocampal neurons’ cytosolic and membrane-bound ribosomal transcript profiles are differentially regulated by learning and subsequent sleep

“…Because both learning and sleep alter hippocampal activity, intracellular signaling, and function ( 18 , 19 , 48 , 49 ), we next tested how cytosolic and MB ribosome-associated transcripts in different neuron types were affected by prior training on a hippocampus-dependent memory task. Consistent with previous findings from our laboratory and others’ ( 17 – 21 ), post-CFC SD disrupted CFM consolidation in the transgenic mice used in this study ( SI Appendix , Fig. S3 ).…”

“…Memory for this context-shock pairing is consolidated via hippocampus-dependent mechanisms over the next few hours ( 16 ). Critically, CFM consolidation can be disrupted by SD over the first 5 to 6 h following CFC ( 17 – 21 ). Over this same post-CFC interval, disruption of either neuronal activity ( 16 ), transcription ( 22 , 23 ), or translation ( 24 – 27 ) in the dorsal hippocampus can likewise disrupt consolidation.…”

Hericium erinaceus mycelium ameliorate anxiety induced by continuous sleep disturbance in vivo

“…Sleep is divided into two distinct states: rapid eye movement (REM) sleep and non-rapid eye movement (NREM) sleep [ 5 , 7 ]. A study showed that changes in NREM sleep often correlate with anxiety levels in mice [ 8 ]. On the other hand, REM sleep latency is a feature of the early symptoms in depression [ 9 ].…”

Effect of the cPKCγ-Ng Signaling System on Rapid Eye Movement Sleep Deprivation-Induced Learning and Memory Impairment in Rats

“…REM-SD can cause a decline in memory and cognitive functions. Therefore, REM sleep plays a key role in learning and memory (4)(5)(6)(7). Neuroimaging is a powerful tool to explore the neural mechanism of sleep disorders.…”