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Keywords

Multi-sensory Integration, Optic Tectum, Neurodevelopmental Disorders, in-vivo Calcium Imaging

Abstract

The superior colliculus (SC) is a mammalian midbrain structure involved in multimodal sensory integration and is implicated to have a role in neurodevelopmental disorders. Although the presence of multisensory integrating neurons (MINs) in the SC has been well documented by electrophysiology techniques, little is known about their morphological or molecular characterization. To identify and study MINs, we utilized SC’s non-mammalian homologous structure–the optic tectum (OT)–in the genetically tractable model organism zebrafish. In this process, we generated transgenic lines that allowed for fluorescent detection of neuronal activity by expressing the genetically engineered calcium indicators: cytoRGECO and H2B-jRGECO1a, respectively in mechanosensory hair cells of the ear and OT. To activate the vestibular sensory pads in 7 days-post-fertilization (dpf) larvae, we used a piezoelectric actuator probe. We found that upon the application of this vestibular stimulus in the posterior cristae (PC), some OT neurons showed time-locked activation. This indicates that OT circuitry in 7dpf larvae is mature enough to receive vestibular stimuli. Furthermore, when 7dpf larvae were sequentially and simultaneously exposed to vestibular and visual stimulations (1 second pulse of 488nm light), we found OT neurons that responded to concurrent stimuli and showed characteristics of multisensory integration. Identification of MINs in the zebrafish OT sets up the stage for better morphological and molecular characterization and their role in neurodevelopmental disorders using a genetically tractable model.

Document Type

Poster

Publication Date

2024-03-21

Language

English

College

Life Sciences

Department

Biology

University Standing at Time of Publication

Junior

Fishing for Neurocircuitry: Identifying Multi-Sensory Integrating Neurons in the Optic Tectum of Zebrafish

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