Optogenetics as a Mechanistic Probe and Therapeutic Tool for Axon Guidance in Neural Regeneration

Abstract

Optogenetic tools have transformed the study of neural circuits, yet their application to axon guidance and neural regeneration remains underexploited. This review critically evaluates how optogenetics has been used—and can be further leveraged—to dissect and control axonal growth mechanisms. We first condense current knowledge of axon guidance cues and intracellular signaling, emphasizing pathways amenable to optogenetic intervention. Next, we analyze optogenetic tools with respect to their suitability for axon guidance studies, highlighting trade-offs between temporal precision, tissue penetration, and signaling specificity. We then synthesize key in vitro and in vivo studies, demonstrating what optogenetics has uniquely revealed about growth cone dynamics, receptor signaling, and circuit refinement. Finally, we identify persistent technical barriers, including opsin expression stability, light penetration, and developmental timing, and propose concrete strategies to overcome them. By framing optogenetics not merely as a manipulation tool but as a mechanistic probe, this review aims to accelerate its translation toward regenerative therapies.