Biphasic effects of ethanol on open-field activity: Sensitivity and tolerance in C57BL/6N and DBA/2N mice.

Abstract

Male C57BL/6N (C57) and DBA/2N (DBA) inbred mice were found to differ in open-field behavior after an acute ip injection of ethanol and in the development of tolerance to repeated injections. DBA mice showed only increased activity for 28 min after ethanol doses up to 2.67 g/kg when compared with saline-injected controls. Under the same conditions, C57 mice showed dose-related increases in activity during the first 4 min, followed by dose-related decreases in activity. The effects endured for at least 60 min after injection in both strains. In a third experiment, mice were injected daily with saline or 2.0 g/kg ethanol and tested on Days 1, 5, 9, and 13 for open-field activity. On the 17th day, all mice were tested after an ethanol injection. Neither strain showed tolerance to the activity-stimulating effect of ethanol. Some evidence for tolerance to the effect of ethanol to reduce activity in C57 mice was found. In a fourth experiment, twice-daily injections of ethanol for 10 days produced marked tolerance to the depressant effect of an injection on the 11th day in C57 mice, compared with those in a control group given ethanol for the first time on the 11th day. No tolerance to the stimulant effect of ethanol was seen in C57s. DBA mice were injected twice daily for 19 days but did not display tolerance when tested on Day 10 or on Day 20. Indeed, DBA mice chronically treated with ethanol exhibited more marked stimulation of activity after ethanol than mice treated chronically with saline. Differences in blood ethanol concentrations between the strains could not account for any of the observed differences. Implications for the genetic control of responses to ethanol are discussed.

Conditioning trial duration affects ethanol-induced conditioned place preference in mice

“…As reported previously, ethanol produced an increase in the activity of DBAI2J mice (e.g., Crabbe, Kosobud, Young, & Janowsky, 1983;Frye & Breese, 1981), and repeated exposure to ethanol on conditioning trials enhanced this stimulant effect (e.g., Crabbe, Johnson, Gray, Kosobud, & Young, 1982; in press; Cunningham & Noble, in press-a; Risinger, Dickinson, & Cunningham, in press). Of greater interest, however, is the apparent relationship between ethanolinduced activation and strength of conditioned place preference.…”

A Null Mutation of the Serotonin 6 Receptor Alters Acute Responses to Ethanol

“…5-HT 6 receptor regulation of ethanol responses SJ Bonasera et al in the first 5 min following administration (Crabbe et al, 1982). This finding suggests that the mutation enhances locomotor activation and/or reduces behavioral sedation in response to low-dose ethanol.…”

Analysis of the biphasic locomotor response to ethanol in high and low responders to novelty: a study in nijmegen wistar rats

“…H igh doses of ethanol are known to decrease locom otor activity in both mice and rats (Pohorecky 1977;D uncan and Baez 1981), while lower doses produce locom otor stimulation in most mouse strains (C arlssonet al 1972;Waldeck 1974;Frye and Breese 1981;Crabbe et al 1982) and some rat strains (Carlsson et a l 1972;M ason et al 1979;Erickson and K ochhar 1985;Waller et al 1986). The mechanisms responsible for this biphasic response, however, are unknown.…”