Withdrawal from repeated treatment with ethanol induces a protracted decrease in novelty-seeking behavior and enhancement of environmental habituation in mice.
Ethanol withdrawal syndrome is characterized by somatic and behavioral symptoms, including increased anxiety and anhedonia. In animal models, however, there are many studies on the anxiogenic effects occurring during the first 24h after ethanol withdrawal, while anhedonia has been overlooked. Recently, we have found that amphetamine withdrawal reduced novelty seeking and enhanced environmental habituation in mice, two motivation-related behaviors. We now investigate the effects of withdrawal from ethanol, a drug of abuse with a different pharmacological profile, on these two motivation-related behaviors. Swiss male mice (3months old) were treated with 1.8g/kg ethanol for 21 consecutive days in their home cages. Seven days after ethanol withdrawal, mice were tested in a free-choice novelty apparatus containing one familiar and one novel compartment. Novelty-seeking behavior was assessed by comparing time spent in the novel compartment versus the familiar compartment, whereas environmental habituation was concomitantly evaluated by the time-response curve of total locomotion (novel+familiar). Novelty seeking was decreased and environmental habituation was enhanced during ethanol withdrawal. These anhedonic responses were not associated with concurrent changes in the anxiety-like behavior of mice (as confirmed in the elevated plus-maze test). We propose that the concomitant evaluation of novelty-seeking behavior and environmental habituation can be useful to study the behavioral consequences not only of amphetamine withdrawal but also of ethanol withdrawal. Furthermore, the present data support recent clinical findings that suggest the occurrence of protracted anhedonia well beyond the limited period immediately following the abrupt cessation of ethanol intake.
Department of Pharmacology, Universidade Federal de São Paulo, R. Botucatu, 862, Ed. Leal Prado, 1° andar, 04023062, São Paulo, SP, Brazil.
Daniela F
DF
Fukushiro
Luis P
LP
Saito
Elisa
E
Mári-Kawamoto
Tatiana C F
TC
Aramini
Jacqueline M
JM
Costa
Fabiana S
FS
Josino
Regina A
RA
Uehara
Roberto
R
Frussa-Filho
D059445:Anhedonia / Q000187:drug effects; D000818:Animals; D001007:Anxiety / Q000523:psychology; D002492:Central Nervous System Depressants / Q000494:pharmacology*; D003627:Data Interpretation, Statistical; D003864:Depression, Chemical; D004777:Environment; D000431:Ethanol / Q000494:pharmacology*; D005106:Exploratory Behavior / Q000187:drug effects*; D006185:Habituation, Psychophysiologic / Q000187:drug effects*; D008297:Male; D051379:Mice; D009043:Motor Activity / Q000187:drug effects; D013375:Substance Withdrawal Syndrome / Q000523:psychology*
D002492:Central Nervous System Depressants; D000431:Ethanol