Acupuncture in Aging-Related Brain Diseases: From Mitochondrial Homeostasis to Clinical Signals

Mitochondria play a key role in maintaining cellular homeostasis through energy metabolism, ROS regulation, calcium handling, and apoptosis control. Mitochondrial dysfunction contributes to neurological vulnerability in the aging brain, where neuronal energy demand, axonal transport, synaptic activity, and neurovascular repair depend on mitochondrial integrity. Animal studies in chronic brain disease and acute brain-injury models have examined acupuncture-related changes in phenotypic outcomes and mitochondrial measures, including behavioral, physiological, and molecular readouts. Their findings span mitochondrial ultrastructure, biogenesis, dynamics, mitophagy, and downstream signaling. Clinical studies have examined acupuncture in Parkinson's disease, stroke, and Alzheimer's disease. Animal studies report acupuncture-related changes in mitochondrial structure and indices of quality control alongside improvements in neurological, behavioral, or injury-related outcomes. These mitochondrial changes may influence oxidative stress, calcium regulation, apoptosis, mitochondrial transport, and intercellular mitochondrial support. Clinical studies mainly report symptom and functional outcomes, while a small number of imaging studies also describe changes in cerebral glucose metabolism or neural activity. These preliminary clinical and metabolic signals may inform further investigation into whether mitochondrial processes are associated with clinical responses to acupuncture. Current experimental work also has important limitations: most studies focus on a limited set of mitochondrial quality-control markers, while the mitochondrial unfolded protein response, axonal mitochondrial trafficking, and dynamic mitochondrial transfer are rarely assessed. Future clinical studies should pair neurological outcomes with feasible measures of mitochondrial function and energy metabolism. Tracking these measures over time may help clarify how changes in mitochondrial function and energy metabolism during acupuncture treatment relate to functional recovery.