Cleal, M., Fontana, B. D., Hillman, C. & Parker, M. O. (2023). Ontogeny of working memory and behavioural flexibility in the free movement pattern (FMP) Y-maze in zebrafish. Behavioural Processes, In Press.
The acquisition of executive skills such as working memory, decision-making and adaptive responding occur at different stages of central nervous system development. Zebrafish (Danio rerio) are commonly used in behavioural neuroscience for increasingly complex behavioural tasks, and there is a critical need to understand the ontogeny of their executive functions. Zebrafish across developmental stages (4, 7, 14, 30 and 90 days post fertilisation (dpf)), were assessed to track development of working memory (WM) and behavioural flexibility (BF) using the free movement pattern Y-maze (FMP Y-maze). Several differences in both WM and BF were identified during the transition from yolk-dependent to independent feeding. Specifically, WM is evident in all age groups, even from 4dpf. However, BF is not developed until larvae become free feeding and then shows significant improvement with age, with young adults (90 dpf) demonstrating the most well-defined behavioural flexibility. We demonstrate for the first time, objective WM processes in 4dpf zebrafish larvae. This suggests that those wishing to study WM in zebrafish may be able to do so from 4dpf, thus drastically increasing throughput. In addition, we show that zebrafish follow distinct stages of cognitive development and age-related changes during the early developmental period. In addition, our findings indicate distinct WM and BF mechanisms, which may be useful to study for translational purposes.
behavioural flexibility; working memory; ontogeny; zebrafish