262 | Representation of Multisensory Stimuli in the Zebrafish Optic Tectum

Sensory and Motor Systems

Author: Nicolas Martorell | Email: martorellnicolas1995@gmail.com

Nicolás Martorell , Valentín Agullo , Violeta Medan

1° Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE – UBA/CONICET)

The optic tectum is a structure of the zebrafish brain directly involved in visual processing. Although previous studies suggest that this region also receives auditory inputs, the precise role of that input in information processing remains an open question. We used genetically encoded calcium sensors (elav3:GCaMP6f) and confocal microscopy to record neural activity in the optic tectum of larval zebrafish in response to auditory, visual, and multisensory stimuli. We found that the optic tectum is not only responsive to auditory cues but that auditory input can be integrated with visual cues resulting in enhanced neural responses. Additionally, we show that neural representations in the optic tectum correlate with activity in premotor areas involved in evasive behaviors. We next asked if the neural representations evoked by each type of stimuli was unique. Dimensionality reduction analysis reveals that, notably, the neural representation of multisensory stimuli aligns closely with either the auditory or visual modality, suggesting the absence of an additional unique representation for multisensory stimuli. These results are consistent with behavioral results from our lab indicating that motor evasive responses to multisensory stimuli also cluster in either a ‘visual’ or an ‘auditory’ escape mode.