Investigating the Role of cadm1b in Cranial Nerve Development and Motor Function in Zebrafish

Abstract

Proper neural network formation requires axons to extend, fasciculate, and establish precise connections with their targets. This process involves numerous axon guidance and cell adhesion molecules. cadm1b, a cell adhesion molecule, is crucial for neural development and is expressed in various regions of the nervous system. Although the roles of cadm1b in synaptogenesis is relatively well known, its involvement in axon guidance remain less understood. Therefore, I aim to elucidate the role of cadm1b in axon pathfinding of cranial nerves using a zebrafish model. I employed transgenic zebrafish embryos expressing olig2-dsRed and HuC-EGFP fluorescent reporters to observe cranial nerve growth in real-time from 36 to 48 hours post-fertilization (hpf) via time-lapse imaging. In zebrafish embryos injected with cadm1b morpholino oligonucleotides (MO), I observed defasciculation and reduced growth of several cranial nerves including trigeminal (V), facial (VII), and vagus (X) nerves. Additionally, these cadm1b-deficient embryos exhibited an increased frequency of spontaneous tail coiling compared to controls. This study provides new insights into the critical functions of cadm1b in neural development and motor behavior in zebrafish.