Ethanol effects on impulsivity in two mouse strains: similarities to diazepam and ketamine.
BACKGROUND
The effects of ethanol on attention and impulsivity have been contradictory.


OBJECTIVE
The aim of the present investigation is to study the effects of acute ethanol administration in measures of attention and response control in the five-choice serial reaction time task (5-CSRTT) in two strains of mice, C57BL/6JOlaHsd and CD1.


METHODS
Mice were trained in the 5-CSRTT and then were injected intraperitoneally (i.p.) with 0, 0.5, 1 and 2 g/kg ethanol before testing under standard parameters and in a long inter-trial interval (ITI) session, which promotes the emergence of premature responses, a measure of poor inhibitory control. To examine if the effects of ethanol in the 5-CSRTT were due to its actions at GABA(A) receptors or at NMDA receptors, the GABA(A) receptor agonist diazepam (1 and 2 mg/kg, i.p.) and the non-competitive NMDA antagonist ketamine (10 and 20 mg/kg, i.p.) were tested in long ITI sessions.


RESULTS
Ethanol did not affect attention or impulsivity in the standard procedure, but increased premature responding in long ITI sessions. The effects of ethanol were mimicked by diazepam in both strains of mice, whereas ketamine increased premature responding only in the CD1 strain.


CONCLUSIONS
Ethanol's ability to increase impulsivity in the 5-CSRTT is mediated by both common and different neurotransmitter systems in the two strains of mice and is dependent on the task's parameters. Furthermore, ethanol did not decrease response accuracy, suggesting that attentional mechanisms are preserved after acute ethanol in mice and that the increases in impulsive behaviour are independent of attentional performance.
Oliver
Yolanda Peña
YP
Department of Psychology, University of Sussex, Falmer, Brighton, BN1 9QG, UK.
Ripley
Tamzin L
TL
Stephens
David N
DN
D000818:Animals; D001288:Attention / Q000187:drug effects*; D002492:Central Nervous System Depressants / Q000008:administration & dosage / Q000494:pharmacology*; D003975:Diazepam / Q000008:administration & dosage / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000008:administration & dosage / Q000494:pharmacology*; D018691:Excitatory Amino Acid Antagonists / Q000008:administration & dosage / Q000494:pharmacology; D018757:GABA Modulators / Q000008:administration & dosage / Q000494:pharmacology; D007175:Impulsive Behavior; D007649:Ketamine / Q000008:administration & dosage / Q000494:pharmacology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D011930:Reaction Time / Q000187:drug effects; D011963:Receptors, GABA-A / Q000187:drug effects / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects / Q000378:metabolism; D013045:Species Specificity
D002492:Central Nervous System Depressants; D018691:Excitatory Amino Acid Antagonists; D018757:GABA Modulators; D011963:Receptors, GABA-A; D016194:Receptors, N-Methyl-D-Aspartate; D000431:Ethanol; D007649:Ketamine; D003975:Diazepam