Objective: To determine whether enhancing resilience of substantia nigra dopaminergic neurons preserves motor circuit integrity.

Background: Degeneration and dysfunction of substantia nigra pars compacta (SNpc) dopaminergic neurons are central features of Parkinsonian motor impairment. While degeneration of the nigrostriatal pathway is well established, it remains unclear whether improving the resilience of nigral dopamine neurons can stabilize broader motor regulatory circuits. Sirtuin 3 (SIRT3), a mitochondrial deacetylase associated with neuronal stress resistance, may enhance dopaminergic neuronal resilience.

Method: Adeno-associated virus serotype 1 encoding Sirt3 (AAV-SIRT3) was stereotaxically delivered to the substantia nigra of adult mice. Dopaminergic activity, motor behaviors, and structural integrity of motor circuits were examined using behavioral assays and histological analyses of dopaminergic, cortical, and spinal motor pathways.

Results: Sustained SIRT3 upregulation in nigral dopaminergic neurons enhanced dopaminergic activity and improved motor performance. SIRT3-overexpressing mice showed preservation of tyrosine hydroxylase–positive neurons in the substantia nigra and improved locomotor and motor coordination compared with controls. Preservation of nigral dopaminergic neurons was associated with maintained integrity of broader motor circuits, including cortical and spinal motor neurons. These findings suggest that enhancing nigral dopaminergic resilience stabilizes motor circuit function beyond the nigrostriatal pathway.

Conclusion: Enhancing mitochondrial function in nigral dopaminergic neurons preserves motor circuit integrity and improves motor function. These findings suggest that targeting nigral dopaminergic neurons may represent a potential therapeutic strategy against sarcopenia.

« Back to 2026 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/sirt3-upregulation-in-nigral-dopaminergic-neurons-preserves-motor-circuit-integrity-for-anti-sarcopenia/