Facilitation by alcohol of active avoidance acquisition performance in the goldfish

Abstract

Common goldfish ( Carassius auratus) were exposed for 3 hr or 6 hr to alcohol solution (628 mg per 100 ml) or were treated identically but never exposed to alcohol. Following pretraining exposure, fish were given 20 trials of active dark-avoidance training in individual shuttle boxes. Alcohol-treated fish obtained significantly higher mean levels of correct responding during acquisition. The enhancement of acquisition performance was not appreciably altered by 6-hr compared with 3-hr pretraining exposure. Neither was the enhanced acquisition performance attributable to increased general shuttling during the 10-sec shock-free conditioned stimulus period. There was some evidence that alcohol-treated fish, compared with controls, swam into and out of the electrified compartment more often during training; however, this sort of responding correlated with correct responding no better for alcohol-treated than for control fish. In another experiment, alcohol was shown to increase sensitivity to light in goldfish. The explanation of the observed facilitation by alcohol of acquisition performance in goldfish may involve an effect on stress or anxiety; an effect of increased sensitivity to electric shock; or an effect of acute increased availability of central monoamines.