Chemoptogenetic ablation of neuronal mitochondria in vivo with spatiotemporal precision and controllable severity

Area of Science:

• Neuroscience
• Mitochondrial Biology
• Genetics

Background:

• Mitochondrial dysfunction is a key factor in many neurological diseases.
• Current experimental methods struggle to target specific mitochondria in defined neuronal populations in vivo.
• Understanding mitochondrial roles in neuronal health requires precise experimental tools.

Purpose of the Study:

• To develop a novel chemoptogenetic approach for targeted mitochondrial damage in neuronal groups within a living organism.
• To investigate the direct impact of mitochondrial dysfunction on neuronal bioenergetics and behavior.
• To establish a causal link between mitochondrial health and neurological function.

Main Methods:

• Engineered transgenic zebrafish to express a fluorogen-activating protein (dL5**) in neuronal mitochondria.
• Utilized a chemical fluorogen (MG2I) that generates singlet oxygen upon activation by far-red light.
• Administered MG2I and exposed zebrafish to far-red light to induce targeted mitochondrial damage in vivo.

Main Results:

• MG2I and light exposure caused significant, dose-dependent neurobehavioral deficits in zebrafish.
• Observed neuronal bioenergetic crisis, acute depolarization, and loss of neuronal respiration.
• Mitochondrial damage included fragmentation, swelling, and cristae elimination, leading to eventual neuronal death.

Conclusions:

• The developed chemoptogenetic tools enable precise in vivo investigation of mitochondrial function and dysfunction in neurons.
• Demonstrated a direct relationship between mitochondrial integrity, neuronal bioenergetics, and whole-animal behavior.
• Provides a powerful model for studying mitochondrial homeostasis and pathophysiology in neurological contexts.