A dose for the wiser is enough: The alcohol benefits for associative learning in zebrafish

• Published in: Progress in neuro-psychopharmacology & biological psychiatry 2014-08, Vol.53, p.109-115
• Main Authors: Chacon, Diana M., Luchiari, Ana C.
• Format: Article
• Language: English
• Subjects: Addictive behaviors; Adult and adolescent clinical studies; Animals; Association Learning - drug effects; Biological and medical sciences; Conditioned learning; Conditioning, Classical - drug effects; Danio rerio; Dose-Response Relationship, Drug; Drug addiction; Drug seeking behavior; Drug-Seeking Behavior - drug effects; Ethanol; Ethanol - pharmacology; Freshwater; Medical sciences; Neuropharmacology; Pharmacology. Drug treatments; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Substance Withdrawal Syndrome - etiology; Time Factors; Zebrafish
• ISSN: 0278-5846; 1878-4216
• DOI: 10.1016/j.pnpbp.2014.03.009

This study aimed to test seeking behavior caused by alcohol and the drug effects on learning in the zebrafish, Danio rerio. Three treatments were conducted: acute, chronic and withdrawal, using 0.10%, 0.25%, and 1.00% alcohol and control (0.00%) (vol/vol.%). For the drug seeking behavior, we used a place preference paradigm (shuttle box tank) before and after alcohol exposure in acute (single exposure) and chronic (7days) treatments. We observed a change in the basal preference due to the association with alcohol only for 0.25% and 1.00% doses in both acute and chronic offering, indicating an alcohol-seeking behavior after the drug exposure. For the learning task, two treatments were tested: chronic alcohol exposure (26days including the learning period) and alcohol withdrawal (15days of alcohol exposure before the learning period). During the learning period, fish received light stimulus followed by food in a pre-defined area of the tank for 8 consecutive days. The low dose group (0.10%) learned the task by the 3rd day both in chronic and withdrawal treatments. The higher doses (0.25% and 1.00%) caused a learning impairment in the chronic treatment group, while fish from the alcohol withdrawal treatment displayed learning on the final testing day. Therefore, we suggest that high alcohol doses impair learning and cause drug seeking behavior, even after drug exposure cessation, while low doses positively affect learning and do not cause seeking behavior. Given our results we propose that the zebrafish is a promising model for identifying active compounds, antibodies or genes which modulate the alcohol dual effects: learning improvement and reinforcing behavior. •We tested alcohol seeking behavior and learning effects in the zebrafish.•Acute and chronic exposure to 0.25% and 1.00% induced alcohol-seeking behavior.•0.25% and 1.00% alcohol impaired learning and 0.10% caused an anticipatory response.•High alcohol doses affect learning and cause prolonged seeking behavior.•Low alcohol doses do not impair learning or cause drug pursuing.