Effect of ethanol, bourbon and various ethanol levels on Y-maze learning in the goldfish

Summary

Large goldfish, 15–20 cm long, were trained in a continuous Y-maze in two continuous and concomitant experiments. In the first experiment synthetic ethanol solutions of 400 mg/100 ml (400 mg-%), and 650 mg-% were compared with water controls as to the rate of learning after 2 hours exposure to the same ethanol solutions, respectively. In the second experiment synthetic ethanol solutions, with a low congener content, of 400 mg-%, 550 mg-% and 650 mg-% and a bourbon solution of 650 mg-% with a high congener content, were compared to water controls as to rate and retention of learning after varying time intervals. Four major results were obtained. First, large amounts of ethanol generally interfere with performance. Second, that subjects after 6 hours of continuous exposure had “adapted” to high levels of ethanol and performed similar to water controls or subjects after 72 hours of continuous exposure. Third, that the reduction in the observed pharmacological effect of ethanol is due more to the prolonged presence of ethanol in the brain than to whether the level is rising or falling. Fourth, that there is a difference between the behavioral effect of ethanol, with a low congener content (similar to vodka) and bourbon with a high congener content. That is, the fish with bourbon learned more poorly than fish in ethanol solutions. The goldfish with its simple neuroanatomy and behavior is offered as a heuristic model to further delineate the variables of dose level, previous experience with alcohol at a given or rising level, initial exposure to alcohol or “adaptation” of the C.N.S. to its continuous presence and the type of beverage as to its congener content.