Impact of early life stress on behaviour and dorsal raphe serotonergic activity in zebrafish (Danio rerio)

Abstract

Exposure to stress in early life stages may lead to structural and functional changes in a developing brain. These changes can increase the risk of cognitive and behavioural abnormalities, which further increase the risk of developing mental disorders in adulthood. My doctoral work investigated the effects of early life stress exposure on growth, behaviour and neural activity using zebrafish as an animal model.

To perform my study, I developed a novel early life stress model in zebrafish. This model exposed zebrafish at their larval stages to a variety of stressors over a chronic duration of time. Following chronic stressor exposure, I observed a reduction in growth and an increase in anxiety-like behaviours in larval zebrafish. Further, using transgenic zebrafish with fluorescent labelled serotonergic neurons in the brain, I have investigated the changes in neural responses after early life stress exposure. I discovered that early life stress exposure results in decreased serotonergic responses to aversive conditions. Together, my research indicates that early life stress in zebrafish negatively impacts growth, behaviour and serotonergic responses. This research highlights the potential role of stress-induced alterations in serotonergic activity in mediating maladaptive stress behaviours.