SLC6A4 and Anxiety: The reduced BDNF mRNA levels in response to ELS in the ventral hippocampus of SERT+/− rats could contribute to the anxiety- and depressive-like phenotypes, while increased BDNF mRNA levels found in the dorsal hippocampus after ELS exposure may result in the beneficial effects on cognition, contributing to the “for better or worse” theory of Belsky.