Objective To investigate the changes of neurotransmitters and the relationship between neurotransmitters and nerve regeneration during the optic regeneration in zebrafish. Methods Using the classical retinotectal regeneration model and electromicroscopy, we observed the ultrastructural changes of synapses of the superficial fiber and gray stratum(SFGS) in the tectum. Results The morphological changes of synapses can be divided into 4 stages: 1. Synaptic degeneration at the early stage after lesion. 2. Regenerating optic nerve fibers entered the SFGS laminar of the tectum, the densities of large granule vesicles (LGV) and small granule vesicles(SGV) were increased. 3. Lots of synapses were formed, the densities of small round clear vesicles (SCV) and small flat clear vesicles(FCV)were increased dramatically .4. Morphological recovery and refinement of the retinotopic innervation. Conclusion Neurotransmitters might play an important role during the regeneration of optic nerve, and they exhibited their effects in a chronological way.

Objective To investigate the changes of neurotransmitters and the relationship between neurotransmitters and nerve regeneration during the optic regeneration in zebrafish.Methods Using the classical retinotectal regeneration model and electromicroscopy,we observed the ultrastructural changes of synapses of the superficial fiber and gray stratum(SFGS)in the tectum. Results The morphological changes of synapses can be divided into 4 stages:1.Synaptic degeneration at the early stage after lesion.2. Regenerating optic nerve fibers entered the SFGS laminar of the tectum,the densities of large granule vesicles(LGV)and small granule vesicles(SGV)were increased.3. Lots of synapses were formed,the densities of small round clear vesicles(SCV)and small flat clear vesicles(FCV)were increased dramatically.4. Morphological recovery and refinement of the retinotopic innervation.Conclusion Neurotransmitters might play an important role during the regeneration of optic nerve,and they exhibited their effects in a chronological way.