Associative learning performance is impaired in zebrafish (Danio rerio) by the NMDA-R antagonist MK-801

► Zebrafish performed well in a plus maze associative learning task. ► MK-801 disrupted memory performance when administered after training. ► MK-801 disrupted memory performance when administered before memory probe trial. ► MK-801 did not disrupt memory performance when administered before training. ► The results suggest good face and construct validity of the zebrafish learning task.