Effect of chronic sleep deprivation and sleep recovery on hippocampal CA3 neurons, spatial memory and anxiety-like behavior in rats

Suresh Konakanchi; Venkateswarlu Raavi; Harendra Kumar Ml; Vinutha Shankar Ms

doi:10.1016/j.nlm.2021.107559

Effect of chronic sleep deprivation and sleep recovery on hippocampal CA3 neurons, spatial memory and anxiety-like behavior in rats

Neurobiol Learn Mem. 2022 Jan:187:107559. doi: 10.1016/j.nlm.2021.107559. Epub 2021 Nov 20.

Authors

Suresh Konakanchi¹, Venkateswarlu Raavi², Harendra Kumar Ml³, Vinutha Shankar Ms⁴

Affiliations

¹ Department of Physiology, Sri Devaraj Urs Medical College, Sri Devaraj Urs Academy of Higher Education and Research (Deemed to be University), Kolar 563103, Karnataka, India.
² Department of Cell Biology and Molecular Genetics, Sri Devaraj Urs Academy of Higher Education and Research (Deemed to be University), Kolar 563103, Karnataka, India.
³ Department of Pathology, Sri Devaraj Urs Medical College, Sri Devaraj Urs Academy of Higher Education and Research (Deemed to be University), Kolar 563103, Karnataka, India.
⁴ Department of Physiology, Sri Devaraj Urs Medical College, Sri Devaraj Urs Academy of Higher Education and Research (Deemed to be University), Kolar 563103, Karnataka, India. Electronic address: vinutha.shankar@gmail.com.

PMID: 34808338
DOI: 10.1016/j.nlm.2021.107559

Abstract

Sleep deprivation-induced degenerative changes in the brain lead to the impairment of memory, anxiety, and quality of life. Several studies have reported the effects of sleep deprivation on CA1 and dentate gyrus regions of the hippocampus; in contrast, there is less known about the impact of chronic sleep deprivation (CSD) and sleep recovery on CA3 neurons and behavior. Hence, the present study aimed to understand the effect of CSD and sleep recovery on hippocampal CA3 neurons and spatial memory, and anxiety-like behavior in rats. Sixty male rats (Sprague Dawley) were grouped as control, environmental control (EC), CSD, 5 days sleep recovery (CSD + 5D SR), and 21 days sleep recovery (CSD + 21D SR). CSD, CSD + 5D SR and, CSD + 21D SR group rats were sleep deprived for 21 days (18 h/day). After CSD, the CSD + 5D SR and CSD + 21D SR rats were sleep recovered for 5- and 21-days respectively. Oxidative stress, dendritic arborization of CA3 neurons, spatial memory, and anxiety-like behavior was assessed. Spatial memory, basal, and apical dendritic branching points/intersections in hippocampal CA3 neurons were reduced, and anxiety-like behavior and oxidative stress increased significantly in the CSD group compared to control (p < 0.001). The CSD + 21D SR showed a significant improvement in spatial memory, reduction in anxiety-like behavior, and oxidative stress when compared to the CSD group (p < 0.05). The basal and apical dendritic branching points/intersections in hippocampal CA3 neurons were increased after CSD + 21D SR, however, it was not significant (p > 0.05). Even though the CSD + 21D SR showed a significant improvement in all the parameters, it did not reach the control level. There was an improvement in all the parameters after CSD + 5D SR but this was not significant compared to the CSD group (p > 0.05). Overall results indicate that the CSD-induced impairment of spatial memory and anxiety-like behavior was associated with oxidative stress and reduced dendritic arborization of hippocampal CA3 neurons. The CSD + 21D SR significantly reduced the damage caused by CSD, but it was not sufficient to reach the control level.

Keywords: Chronic sleep deprivation; Dendritic arborization; Oxidative stress; Sleep recovery; Spatial memory.

MeSH terms

Animals
Anxiety*
Behavior, Animal*
Brain
CA3 Region, Hippocampal / physiopathology*
Male
Neuronal Plasticity
Neurons / drug effects*
Oxidative Stress / physiology
Rats
Rats, Sprague-Dawley
Sleep Deprivation / complications*
Spatial Memory / physiology*