Taurine prevents memory consolidation deficits in a novel alcohol-induced blackout model in zebrafish

Ethanol is one of the most consumed substance worldwide that impairs learning and memory processes, resulting in amnesia or blackout. Due to the genetic conservation, rich behavioral repertoire, and high pharmacological tractability, the zebrafish (Danio rerio) has emerged as a powerful model organism for assessing preventive strategies against the noxious effects of ethanol in vertebrates. Here, we used an inhibitory avoidance apparatus to investigate the potential preventive effects of taurine in a novel ethanol-induced amnesia model in zebrafish. The experimental tank consisted of two compartments of the same size, one dark and another white, which were separated by a guillotine-type door. Three parallel metal bars coupled to an electrical stimulator were connected on each lateral wall of the dark compartment as electrical stimulus source. Differences on the latency to enter the dark compartment were used as retention indexes. A mild electric shock (125 mA, 3 ± 0.2 V) at 10 and 1000 Hz did not promote significant learning, while 100 Hz facilitated memory retention. Posttraining administration of MK-801 blocked this response, reinforcing the predictive validity of the test. Treatments were performed immediately after the training session using the 100 Hz frequency. Animals were exposed to water (control), taurine (42, 150, 400 mg/L), ethanol (0.25%, 1.0% v/v) or taurine plus ethanol to assess the effects on memory consolidation. Test session was performed 24 h following training. Ethanol at 0.25% did not affect memory consolidation, but 1.0% impaired memory without changing locomotion. Although taurine alone did not modulate learning, all concentrations tested exerted prevented ethanol-induced memory impairment. Overall, we describe a novel ethanol-induced blackout model, where a high ethanol concentration acutely impairs memory consolidation in zebrafish. Moreover, since taurine showed a protective role, we reinforce the growing utility of zebrafish models for assessing the deleterious effects of ethanol and potential therapeutic strategies.