Oral self-administration of ethanol and not experimenter-administered ethanol facilitates rewarding electrical brain stimulation.
The effects of ethanol on brain-stimulation reward (BSR) were investigated in rats orally self-administering ethanol. Electrodes were stereotaxically implanted in the medial forebrain bundle (MFB) of male F-344 rats. A rate free threshold procedure was used. Animals demonstrated significant threshold-lowering effects after considerable ethanol self-administration experience. To elucidate the significance of the contingent nature of the route of administration in the threshold-lowering effects of ethanol on BSR, a comparison of animals self-administering ethanol to yoked animals receiving it passively through a gastric cannula was made. Significant threshold-lowering effects were only found in the animals self-administering ethanol and not those receiving it noncontingently. Thus, to the extent that brain-stimulation reward is a model of drug-induced euphoria, these results suggest that the reinforcing effects of ethanol are dependent to a greater degree on an interaction between experimental, environmental and pharmacological factors, than other abused drugs.
Boston University School of Medicine, MA 02118.
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M
Moolten
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Kornetsky
D000428:Alcohol Drinking / Q000502:physiology*; D000818:Animals; D001921:Brain / Q000502:physiology*; D004558:Electric Stimulation; D000431:Ethanol / Q000494:pharmacology*; D006801:Humans; D012201:Reward; D012646:Self Administration / Q000523:psychology*
D000431:Ethanol