Sex- and Age-dependent Differences in Sleep-wake Characteristics of Fisher-344 Rats. (10th February 2020)

• Record Type: Journal Article
• Authors: Kostin, Andrey; Alam, Md. Aftab; Siegel, Jerome M.; McGinty, Dennis; Alam, Md. Noor
• Is Part Of: Neuroscience. Volume 427(2020)
• Page Start: 29
• Page End: 42
• Publication Date: 2020-02-10
• Subjects: AW active-waking -- DE diestrus -- EEG electroencephalogram -- EMG electromyogram -- FFT Fast Furier Transform -- ME metestrus -- nonREM non-rapid eye movement -- QW quiet-waking -- REM rapid-eye movement; rat -- sleep -- wakefulness -- aging -- male -- female; Neurochemistry -- Periodicals; Neurophysiology -- Periodicals; Neurology -- Periodicals; Neurochimie -- Périodiques; Neurophysiologie -- Périodiques; Neurochemistry; Neurophysiology; Electronic journals; Periodicals; Electronic journals; 612.8
• DOI: 10.1016/j.neuroscience.2019.11.046
• Languages: English
• ISSNs: 0306-4522

Abstract

Highlights: Biological sex and aging are recognized risk factors for sleep disruption and insomnia. We examined sex- and age-dependent differences in spontaneous and homeostatic sleep response profiles of Fischer-344 rats. Cycling females exhibited similar sleep-wake features across estrus cycle except for decreased REM sleep at proestrus night. Sleep-wake architecture in both sexes were similar except for higher delta power in nonREM recovery sleep in females. Aging adversely affected sleep-wake organization and the effects of aging were comparable in both sexes. Abstract: Aging is a well-recognized risk factor for sleep disruption. The characteristics of sleep in aging include its disruption by frequent awakenings, a decline in both non-rapid eye movement (nonREM) and REM sleep amounts, and a weaker homeostatic response to sleep loss. Evidence also suggests that sleep in females is more sensitive to changes in the ovarian steroidal milieu. The Fischer-344 rats are commonly used experimental subjects in behavioral and physiological studies, including sleep and aging. Most sleep studies in Fischer-344 rats have used male subjects to avoid interactions between the estrus and sleep-waking cycles. The changes in the sleep-wake organization of female Fischer-344 rats, especially with advancing age, are not well-characterized. We determined sleep-waking features of cycling females across estrus stages. We also compared spontaneous and homeostatic sleep response profiles of young (3-4 months) and old (24-25 months) male and female Fischer-344 rats. The results suggest that: i) sleep-wake architectures across stages of estrus cycle in young females were largely comparable except for a significant suppression of REM sleep at proestrus night and an increase in REM sleep the following day; ii) despite hormonal differences, sleep-wake architecture in male and female rats of corresponding ages were comparable except for the suppression of REM sleep at proestrus night and higher nonREM delta power in recovery sleep; and iii) aging significantly affected sleep-wake amounts, sleep-wake stability, and homeostatic response to sleep loss in both male and female rats and that the adverse effects of aging were largely comparable in both sexes.