The lateral habenula (LHb) is a key structure that controls both dopaminergic and serotonergic pathways, which support motivational, motor, and cognitive functions. It is strongly involved in negative reward processing, and its dysfunction has been linked to depression. During early development, when neural circuits are being formed, the brain is highly sensitive to environmental inputs. Lack of proper stimulation in this critical period can cause lasting deficits. Social interaction is particularly important for shaping normal behaviors, and early-life social isolation is a major risk factor for neuropsychiatric disorders, including depression. We aim to study the role of the habenula in behavioral changes caused by social isolation during early development in larval zebrafish. Here we present preliminary results on activity of Habenular neurons of 6-16 days old larval zebrafish in response to audiovisual stimuli. For in vivo calcium imaging, we used transgenic zebrafish expressing GCaMP6f (Nacre[elavl3:GCaMP6f]). Confocal images were motion-corrected (CaImAn) and segmented (Cellpose) to measure fluorescence from individual neurons. We analyzed spontaneous and stimulus-evoked activity in animals raised in a social (control) context from 6 to 16 days old to see how habenular activity changes during development. In addition, we compared activity between control and isolated groups to test if lack of social interaction affects stimulus processing in the Habenula.