Effects of adolescent ethanol exposure on sleep in adult rats

Abstract

Although adolescent ethanol (EtOH) exposure has been associated with long-lasting changes in brain function, little is known as to whether EtOH exposure during adolescence alters sleep and cortical arousal. This study examined protracted alterations in sleep in adult rats exposed to EtOH during adolescence. Adolescent male Wistar rats were exposed to EtOH vapor for 12 hr/day for five weeks. Cortical electroencephalograms (EEGs) were obtained during 4-hr recording sessions after five weeks of withdrawal from EtOH. Adolescent EtOH exposure significantly reduced the mean duration of slow-wave sleep (SWS) episodes and the total amount of time spent in SWS in EtOH-exposed rats, compared to controls. Spectral analysis revealed that adolescent EtOH exposure significantly increased cortical peak frequencies during SWS in the 2-4 Hz, 4-6 Hz and 6-8 Hz bands. Taken together, our findings suggest that chronic EtOH exposure in adolescent rats reduces measures of SWS, an effect also seen as part of normal aging. Although the cellular and molecular mechanisms mediating the consequences of EtOH exposure on the aging process are not known, the similarities between adolescent EtOH exposure and aging merits further investigation.

Adolescent intermittent ethanol reduces serotonin expression in the adult raphe nucleus and upregulates innate immune expression that is prevented by exercise

“…Adolescent intermittent ethanol increases adult anxiety-like behaviors (Sakharkar et al, 2014; Vetreno et al, 2015), induces depressive-like behavior in adulthood (Ehlers et al, 2011; Slawecki et al, 2004), disrupts sleep (Criado et al, 2008), and increases impulsivity in adulthood (Ehlers et al, 2011; Gass et al, 2014) that might be secondary to reduced 5-HT+IR neurons in the DRN. Serotoninergic system dysfunction is associated with depression and alcoholism, which are co-morbid in humans (Kelley and Dantzer, 2011).…”

Developmental ethanol exposure-induced sleep fragmentation predicts adult cognitive impairment

“…Disruption of sleep following developmental EtOH exposure has been reported in both human infants (Troese et al, 2008, Chen et al, 2012) and rodents (Stone et al, 1996, Criado et al, 2008, Volgin and Kubin, 2012). The previous rodent work has focused on monitoring sleep over short periods (3-5hrs), and/or focused on infant animals (Hilakivi, 1986).…”

“…Beyond the initial wave of ethanol induced damage such as cell death, there is a cascade of cellular, synaptic and network consequences induced by early ethanol exposure – some as a direct result of the ethanol insult, and some as a secondary response to cellular changes induced by that initial insult. One of the many functions that are disrupted by early ethanol exposure is sleep-wake structure (Criado et al, 2008, Pesonen et al, 2009, Jan et al, 2010, Wengel et al, 2011, Volgin and Kubin, 2012). …”

“…In individuals with FASD (Troese et al, 2008, Pesonen et al, 2009, Wengel et al, 2011, Chen et al, 2012) and in animal models of early ethanol exposure (Criado et al, 2008, Volgin and Kubin, 2012) sleep becomes more fragmented. Sleep fragmentation refers to shortened sleep bouts and frequent transitions between sleep and wake states.…”

“…Here, in an extension of previous work that focused on analysis of developmental ethanol effects on relatively brief periods of sleep/waking (Stone et al, 1996, Criado et al, 2008, Volgin and Kubin, 2012), we explored slow-wave sleep over a multi-day period in adult mice exposed to a single exposure of ethanol on postnatal day 7 (P7). In the same mice, we examined developmental ethanol induced behavioral hyperactivity in the home cage and hippocampal-dependent contextual fear memory impairment, to assess whether these behavioral outcomes correlated with sleep disruption.…”