Relationship between ethanol-induced activity and anxiolysis in the open field, elevated plus maze, light-dark box, and ethanol intake in adolescent rats

Abstract

It is yet unclear if ethanol-induced motor stimulation in the open field (OF) merely reflects psychomotor stimulating effects of the drug or if this stimulation is driven or modulated by ethanol’s antianxiety properties. In the present study, adolescent rats were administered with different ethanol doses or remained untreated. They were sequentially assessed in the OF, elevated plus maze (EPM), and light-dark box (LDB) and then assessed for ethanol intake. The aims were to assess the relationship between measures of ethanol-induced activity and anxiolysis, analyze ethanol intake as a function of prior ethanol exposure, and associate behavioral responsiveness in these apparatus with ethanol intake during adolescence. The results suggested that the enhanced exploration of the OF observed after 2.5 and 3.25 g/kg ethanol reflected a motor-stimulating effect that appeared to be relatively independent of anxiolysis. The 1.25 g/kg dose induced motor stimulation in the OF and anti-anxiety effects in the EPM, but these effects were relatively independent. The 0.5 g/kg ethanol dose exerted significant anxiolytic effects in the EPM in the absence of stimulating effects in the OF. A multivariate regression analysis indicated that adolescents with a higher frequency of rearing behavior in the OF, higher percentage of open arm entries in the EPM, and lower propensity to enter the central area of the OF exhibited greater ethanol intake. These results indicate that the OF is a valid procedure for the measurement of ethanol-induced stimulation, and provide information towards characterizing subpopulations of adolescents at risk for initiating alcohol drinking.

Refinement of anesthetic choice in procedures preceding psychopharmacological studies

“…Besides that, a subanesthetic dose of tribromoethanol (90mg/kg) induced an anxiolyticlike effect similarly to that of diazepam in the EPM. Corroborating our findings, a lowdose of another primary alcohol, ethanol, increased exploration of the open arms in the EPM and of the light compartment in the light-dark transition test (Acevedo et al 2014). This anxiolytic-like effect of tribromoethanol may be mediated by inhibitory currents through GABA A receptors (Zimmerman et al 1994;Krasowski and Harrison 2000;Thompson and Wafford 2001), similar to the mechanism of the anxiolytic effect of diazepam.…”

Taurine zinc solid dispersions protect against cold-restraint stress-induced gastric ulceration by upregulating HSP70 and exerting an anxiolytic effect

“…The elevated plus-maze test was conducted according to the method of Acevedo et al (2014) with slight modifications. The elevated plus maze test has been widely used effectively to assess the effects of anxiogenic/anxiolytic agents on the neurobehavioral profile of animals.…”

Binge-Like, Naloxone-Sensitive, Voluntary Ethanol Intake at Adolescence Is Greater Than at Adulthood, but Does Not Exacerbate Subsequent Two-Bottle Choice Drinking

“…The rats were tested for ethanol intake and preference in a two-bottle (24 h long) choice test, shortly before (i.e., baseline) and shortly after exposure to the binge protocol; and then were tested for 3 weeks during late adulthood (PDs 120-139) in intermittent two-bottle ethanol intake tests. The effects of the binge-like exposure during adolescence or adulthood upon anxiety response, shelter seeking/risk-taking and recognition memory were also tested, via the light-dark box (LDB) test (Acevedo et al, 2014), the multivariate concentric square field (MSCF) test (Roman and Colombo, 2009;Ekmark-Lewen et al, 2010) and the novel object recognition (NOR) test (Antunes and Biala, 2012), respectively. Experiment 2 assessed if treatment with the opioid antagonist naloxone could inhibit ethanol binge drinking at adolescence, and measured the blood ethanol levels (BELs) achieved during the binge procedure.…”