Human retinal organoids functionally bridge a transected optic nerve in a rat model.

Area of Science:

• Neuroscience
• Regenerative Medicine
• Ophthalmology

Background:

• Functional vision restoration after optic nerve transection in adult mammals is currently not possible.
• Optic nerve injuries can lead to permanent vision loss.

Purpose of the Study:

• To investigate the potential of heterotopic human retinal organoid transplantation for vision restoration.
• To establish a functional relay pathway across a completely transected optic nerve.

Main Methods:

• Heterotopic transplantation of human retinal organoids into the optic nerve transection site in adult rats.
• Assessment of visual function using pupillary light reflex, electrophysiology, and behavioral tests.
• Neuroanatomical tracing and 3D imaging to analyze host-graft integration.
• Chemogenetic manipulation to confirm graft functional engagement.

Main Results:

• Partial recovery of visual function was observed in treated animals.
• Restored visual functions included pupillary light reflex, visually evoked electrophysiological responses, and visually guided behaviors.
• Host-graft coupling across the transection gap was confirmed by tracing and imaging.
• Functional graft engagement was demonstrated by chemogenetic inhibition leading to vision attenuation.

Conclusions:

• Heterotopic retinal organoid transplantation can create a relay pathway for partial signal transmission across a transected optic nerve.
• This study provides proof of concept for a novel approach to repair severe optic nerve injuries.
• Retinal organoid transplantation offers a promising alternative framework for vision restoration in cases of optic nerve damage.