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We recently found that voluntary wheel running attenuated ethanol withdrawal-induced increased susceptibility to chemoconvulsant-induced seizures in male rats. Since female rats recover from ethanol withdrawal (EW) more quickly than male rats across several behavioral measures, this study was designed to determine whether the effects of exercise on EW seizures also exhibited sex differences. Animals were maintained under no-wheel, locked-wheel or free-wheel conditions and ethanol was administered by liquid diet for 14 days with control animals pair-fed an isocaloric diet, after which seizure thresholds were determined at 1 day or 3 days of EW. Consistent with previous reports, females ran significantly more than males, regardless of diet condition. Introduction of the ethanol-containing liquid diet dramatically increased running for females during the day (rest) phase, with little impact on night phase activity. Consistent with previous reports, EW increased seizure susceptibility at 1 day in non-exercising males and females and at 3 days in males. These effects were attenuated by access to running wheels in both sexes. We also assessed the effects of sex, ethanol diet and exercise on ethanol clearance following an acute ethanol administration at 1 day EW in a separate set of animals. Blood ethanol concentrations at 30 min post-injection were lower in males, ethanol-exposed animals, and runners, but no interactions among these factors were detected. Interestingly, females displayed more rapid ethanol clearance than males and there were no effects of either diet or wheel access on clearance rates. Taken together, these data suggest that voluntary wheel running during ethanol administration provides protective effects against EW seizures in both males and females. This effect may be mediated, in part, in male, but not in female rat, by effects of exercise on early pharmacokinetic contributions. This supports the idea that encouraging alcoholics to exercise may benefit their recovery.

Background: Alcohol withdrawal is associated with behavioral and chronobiological disturbances that may persist during protracted abstinence. We previously reported that C57BL/6J (B6) mice show marked but temporary reductions in running-wheel activity, and normal free-running circadian rhythms, following a 4-day chronic intermittent ethanol (CIE) vapor exposure (16 hours of ethanol vapor exposure alternating with 8 hours of withdrawal). In the present experiments, we extend these observations in 2 ways: (i) by examining post-CIE locomotor activity in C3H/HeJ (C3H) mice, an inbred strain characterized by high sensitivity to ethanol withdrawal, and (ii) by directly comparing the responses of B6 and C3H mice to a longer-duration CIE protocol., Methods: In Experiment 1, C3H mice were exposed to the same 4-day CIE protocol used in our previous study with B6 mice (referred to here as the 1-cycle CIE protocol). In Experiment 2, C3H and B6 mice were exposed to 3 successive 4-day CIE cycles, each separated by 2 days of withdrawal (the 3-cycle CIE protocol). Running-wheel activity was monitored prior to and following CIE, and post-CIE activity was recorded in constant darkness to allow assessment of free-running circadian period and phase., Results: C3H mice displayed pronounced reductions in running-wheel activity that persisted for the duration of the recording period (up to 30 days) following both 1-cycle (Experiment 1) and 3-cycle (Experiment 2) CIE protocols. In contrast, B6 mice showed reductions in locomotor activity that persisted for about 1 week following the 3-cycle CIE protocol, similar to the results of our previous study using a 1-cycle protocol in this strain. Additionally, C3H mice showed significant shortening of free-running period following the 3-cycle, but not the 1-cycle, CIE protocol, while B6 mice showed normal free-running rhythms., Conclusions: These results reveal genetic differences in the persistence of ethanol withdrawal-induced hypo-locomotion. In addition, chronobiological alterations during extended abstinence may depend on both genetic susceptibility and an extended prior withdrawal history. The present data establish a novel experimental model for long-term behavioral and circadian disruptions associated with ethanol withdrawal., (Copyright © 2011 by the Research Society on Alcoholism.)

Alcohol withdrawal is associated with affective-behavioral disturbances in both human alcoholics and in animal models. In general, these phenomena are potentiated by increased alcohol exposure duration and by prior withdrawal episodes. Previous studies have also reported locomotor hypoactivity during ethanol withdrawal in rats and mice, but only in novel test environments and not in the home cage. In the present study, we examined the effects of withdrawal from chronic intermittent ethanol (CIE) vapor exposure on the level and circadian periodicity of wheel-running activity in C57BL/6J mice. CIE treatment resulted in reductions in wheel-running activity compared with plain-air controls that persisted for about 1 week after withdrawal. Analysis of circadian waveforms indicated that reduced activity occurred throughout the night phase, but that daily-activity patterns were otherwise unaltered. CIE failed to alter free-running circadian period or phase in animals maintained under constant darkness. These results show that ethanol withdrawal can result in locomotor hypoactivity even in the habitual, home-cage environment, and suggest that withdrawal-related reductions in wheel-running activity may reflect the specific motivational significance of this behavior., (2010 Elsevier Inc. All rights reserved.)

Chronic alcohol intake and alcohol withdrawal are associated with dramatic disruptions of daily (circadian) biological rhythms in both human alcoholics and experimental animals. The extent to which these observations are due to pharmacological effects on the underlying circadian pacemaker is not known, however, since no human studies and very few animal studies have been conducted under free-running conditions. In the present study, free-running circadian activity (wheel-running) rhythms of rats were monitored before, during and after exposure to either 10% or 20% ethanol solution as the only drinking fluid. Across individuals, both lengthening and shortening of free-running period were observed during ethanol intake, and treatment termination led to either a return to baseline or to an exacerbation of the original ethanol effect. These variable effects appeared to be related to both ethanol concentration and to individual differences in baseline period, such that relatively short free-running period during baseline was associated with greater period-lengthening during ethanol exposure. These bidirectional affects of ethanol on free-running period are generally similar to effects seen previously with other psychoactive drugs, including antidepressants. The results of this study indicate that ethanol influences the circadian pacemaker, and that the chronobiological disruptions seen in human alcoholics may be due, in part, to alterations in circadian pacemaker regulation.

This study examined the effects of the alpha 2-adrenergic agonist clonidine on free-running circadian activity rhythms in rats, using a dosing regimen similar to one previously shown to induce behavioral depression in the swim test. In constant light, clonidine consistently shortened the free-running circadian period, reduced circadian amplitude, and reduced the overall level of locomotor activity. These effects were reversed after the termination of clonidine treatment. In constant darkness, clonidine reduced circadian amplitude, but both increases and decreases in free-running period and activity level were observed. Clonidine-induced changes in free-running period and activity level were systematically related to individual differences in baseline activity in both constant light and constant darkness. These results demonstrate that clonidine can alter both the rhythmicity and the level of spontaneous activity, and are consistent with the hypothesis that monoaminergic systems may mediate relationships between behavioral state and circadian rhythmicity.