Longitudinal analysis of visuomotor orientation after optic lobe lesions reveals brain plasticity in Drosophila

Abstract

Acute brain injury disrupts neuro-glial networks leading to impaired brain function. Although injury induces diverse forms of plasticity, their contributions to brain injury outcome remain poorly understood. We previously showed that targeted stab lesions to the optic lobe (OL) of the adult fly brain induce proliferation of glial and neural progenitor cells. Here, we examined the effect of OL lesions on distinct features of fly behavior, which revealed a specific drop in visual stripe fixation performance acutely after injury, whereas locomotor behavior remained mostly unaffected. Using longitudinal studies of injured individuals, we found that flies significantly regain stripe fixation capacity and idiosyncratic traits one week post injury, suggesting a role for plasticity mechanisms. When the proliferation of adult neural progenitor cells is specifically blocked prior to injury, individuals showed no significant improvements of visual orientation during the identified plasticity window suggesting that progenitor activation may support recovery of stripe approach behavior. Hence the individual tracking of orientation behavior emerges as a suitable quantitative framework for studying functional recovery and interindividual variability in the adult Drosophila brain following brain injury.