The Role of Anandamide in Modulating the Effects of Chronic Sleep Deprivation on Memory, brain waves, and Hippocampal Neurons in Male Wistar Rats

Document Type : Original Article

Authors

1 Department of Physiology, Medicine Faculty, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran

2 Persian Gulf Physiology Research Center, Basic Medical Sciences Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran

Abstract
Introduction: Sleep deprivation impairs memory function by altering the function of the endocannabinoid system. In the present study, the effects of administering the endocannabinoid anandamide (AEA) on memory and learning, cortical theta and beta waves, and neuroprotection in the hippocampus were investigated in a chronic sleep deprivation (SD) model in adult male rats.
Methods: Adult male Wistar rats (200-250 g) were randomly assigned to three groups: Control + vehicle (Control), SD + vehicle (SD), and SD + 20 mg/kg AEA (SD + A). To induce SD, the rats were placed in a sleep deprivation apparatus daily for 18 hours (7:00 AM to 1:00 AM) for 21 consecutive days. The electrical power of cortical theta and beta waves was assessed via EEG. Spatial memory tests in the Morris water maze and the passive avoidance test were used to evaluate learning and memory.
Results: Electrophysiological findings revealed that sleep deprivation caused a significant increase in the electrical power of theta and beta waves in the temporal lobe (p<0.05), which is associated with cognitive impairments. Administration of AEA significantly reduced this increased power in the parietal (p<0.01), temporal (p<0.05), and occipital (p<0.05) lobes.
Conclusion: In summary, although AEA was able to modulate the abnormal brain wave pattern, at the dose and protocol used in this study, it could not exert a significant protective role in ameliorating cognitive deficits and neuronal death induced by chronic sleep deprivation. The effects of AEA appear to be dose-dependent and may yield contrasting outcomes at different levels.
Keyword: Sleep deprivation, Anandamide (AEA), Memory and learning, Electroencephalography (EEG).

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