A potential role for BDNF in recognition behavior revealed through knockout in zebrafish.

Introduction: Brain-derived neurotrophic factor (BDNF) is a key player in the molecular mechanisms underlying learning and memory in mammals. Recent studies have shown that mutant fish lacking BDNF exhibit widespread deficits in learning tasks. Moreover, natural variation in brain BDNF gene expression predicts individual differences in learning ability in fish. These findings suggest that the role of BDNF in cognition may be widespread among vertebrates. Methods: Following this hypothesis, we used a Results: Overall, zebrafish did not demonstrate a group-level preference for either stimulus. However, individuals appeared to show variation in their responses to the novel stimulus (either approaching or avoiding it). When accounting for the individual variation, the strength of recognition memory performance was lower in zebrafish lacking Discussion: Our findings suggest that BDNF may be involved in recognition test performance and the underlying behavior, although the nature of this involvement and the contribution of memory processes remain unclear.