Effect of Acute and Chronic Sleep Deficit on Working and Long-Term Memory in Rats

• Published in: Journal of evolutionary biochemistry and physiology Vol. 59; no. 6; pp. 2129 - 2140
• Main Authors: Chernyshev, M. V., Guseev, M. A., Ekimova, I. V.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.11.2023; Springer Nature B.V
• Subjects: Animal Physiology; Biochemistry; Biomedical and Life Sciences; Circadian rhythms; Cognitive ability; Evolutionary Biology; Experimental Papers; Latency; Life Sciences; Long term memory; Memory; Short term memory; Sleep and wakefulness; Sleep deprivation; Sleep disorders; sleep; cognitive functions; working memory; deprivation; chronic sleep restriction; rats; long-term memory
• ISSN: 0022-0930; 1608-3202
• DOI: 10.1134/S0022093023060182

Insufficient sleep or circadian rhythm sleep-wake disorders have a detrimental effect on cognitive functions. It has long been thought that the weakest spot is memory consolidation, i.e., information transfer from short-term/working memory to long-term memory. However, there is a growing body of evidence showing that sleep disorders affect working memory most negatively. Here, we undertook an attempt to assess possible disturbances in working memory and long-term memory following the impact of sleep loss in acute and chronic experiments on rats. An orbital shaker was used to cause sleep deprivation/restriction according to the following protocols: 1—acute sleep deprivation for 18 h; 2—acute sleep restriction for 24 h (3 h of sleep deprivation alternated continuously with 1 h of sleep opportunity, with a total sleep loss of 18 h); 3—chronic sleep restriction (protocol 2 for five consecutive days). Acute sleep deprivation in the Y-maze test led to a significant decrease in the percentage of spontaneous alternations of the maze arms, indicating working memory impairment. In the Barnes maze test, the same exposure had no effect on long-term memory, as the time to enter the escape chamber (escape latency) did not change in this task. Acute and chronic sleep restriction caused no changes in both working and long-term memory. The results allow us to conclude that working memory (in contrast to long-term memory) is a vulnerable element of cognitive functions under conditions of acute sleep deprivation. This negative effect was abolished if sleep deprivation periods alternated with short sleep opportunity periods, indicating a protective significance of short rest/sleep periods for cognitive functions under conditions of sleep deficit. Hence, short-term sleep is beneficial for cognitive health as it protects working memory, whereas continuous long-term wakefulness impairs it.