Environmental enrichment on neural plasticity in juvenile Baltic sturgeon (Acipenser oxyrinchus)

Abstract

Conservation biologists have long emphasized the importance of environmental enrichment in hatcheries which main objective is restocking. In this study, we evaluated the impact that long-term exposure of environmental enrichment in an artificial river section (surface water, ambient light and temperature) has on neural plasticity in juvenile Baltic sturgeons (Acipenser oxyrinchus) in comparison to fish that were reared in glass-fiber tanks in a recirculation system (aquaculture control group) under constant light and temperature conditions and an intermediate group reared in glass-fiber tanks with ambient water and natural photoperiod and temperature fluctuation. All expositions were carried out in triplicate. From the three markers reported to indicate neural plasticity, only an up-regulation of neurod1 in the forebrain of Baltic sturgeon (A. oxyrinchus) reared in enriched environment was observed in comparison to the semi-natural group and to the aquaculture (control) group. The two other markers (brain-derived neurotropic factor (bdnf), and proliferating cell nuclear antigen (pcna) did not reveal any significant differences between the groups. In conclusion, only minor effects of environmental enrichment on neuroplasticity were observed here.