Meeting Abstract

17.5  Monday, Jan. 4  Environmental Effects on Drosophila Brain Development and Learning ROBERTS, S.P.*; WANG, X.; DE BELLE, J.S.; Central Michigan University; University of Nevada Las Vegas; University of Nevada Las Vegas stephen.roberts@cmich.edu

Brain development and cognition are sensitive to environmental perturbations experienced by sub-adult organisms. However, little is known about how (A) multiple stressors interact to affect these traits, (B) protective mechanisms can mitigate such damage and (C) anatomical structures of the brain and/or cognitive functions are differentially sensitive to deleterious effects of stressful environments. We addressed these issues by testing the effects of sub-adult heat shock (variably coupled with stress response-inducing heat pretreatment), larval density and early-adulthood sensory enrichment on external and brain anatomical features and olfactory learning in mature adult Drosophila melanogaster. A stress response-inducing heat pretreatment administered prior to daily heat shock of sub-adults partially mitigated heat-shock mushroom body phenotypes and, to a lesser degree, learning impairments. In thermally-benign conditions, wing area, leg length and the volumes of adult antennal lobes and optic lobes were inversely related to larval rearing density, while mushroom body and central complex volumes were less sensitive to rearing density. Likewise, adult learning ability was unaffected by larval rearing density. Daily heat stress during sub-adult development had no effect on wing area, leg length, optic lobe volume and central complex volume, but muted the rearing density-dependence of most features. Sensory enrichment during early adulthood did not mitigate mushroom body developmental damage caused by daily heat shock in sub-adult stages. These results suggest that, in various stressful rearing environments, the mushroom body’s plasticity contributes to both its likelihood of damage and its developmental fidelity relative to other brain structures.