C57BL/6J mice showed dose dependent devreases in locomotor activity with increasing IP doses of ethanol (0.0, 0.75, 1.50 and 2.25 g/kg), while BALB/cJ mice showed dose dependent increases in activity; both strains were equally active with saline. Whether this finding represents decreased CNS responsivity in C57BL mice to ethanol's excitatory effect or increased response to its depressant action at sub-hypnotic doses is unclear, since anesthetic doses produce anesthesia of far shorter duration in the C57BL strain than in the BALB strain. It is possible that the biphasic action of alcohol is under the control of separate and distinct mechanisms, rather than a common one, and that these two mechanisms are differentially affected by alcohol. Endogenous as well as ethanol-induced neurochemical differences in biogenic amines may also be correlated with the gentic variation in CNS responsivity towards alcohol.

Animals↗

PubMedDate not supplied

Illustration of a control problem in alcohol research designs.

Issues of control problems in alcohol research, resulting from studies of a possible alcohol placebo effect, are discussed. These concern how the control response is related to the pre-drug response as well as the stability of both.

Alcoholism↗

PubMedDate not supplied

Development of tolerance to ethanol-induced tachycardia in rats.

Development of tolerance to ethanol was examined using heart rate as a measure. Ethanol-treated rats were infused IG with 8-11 g/kg/day (in 3 divided doses), control rats received similar infusions of either equicaloric dextrin-maltose or water (equivolumetric) for a period of 17 days. On days 1, 5, 9, 13 and 17 of treatment heart rate was recorded before and at 10, 20 and 30 minutes after injection of a challenge dose of 2 g/kg ethanol, dextrin-maltose or water. The tachycardia produced by ethanol increased with days of chronic treatment to a maximum on the 9th day of treatment. Significant tolerance to the tachycardia was evident only on the 17th day of treatment. Neither control showed significant changes in heart rate.

Animals↗