Exercise-linked improvement in age-associated loss of balance is associated with increased vestibular input to motor neurons.
Age-associated loss of muscle function is exacerbated by a concomitant reduction in balance, leading to gait abnormalities and falls. Even though balance defects can be mitigated by exercise, the underlying neural mechanisms are unknown. We now have investigated components of the proprioceptive and vestibular systems in specific motor neuron pools in sedentary and trained old mice, respectively. We observed a strong age-linked deterioration in both circuits, with a mitigating effect of exercise on vestibular synapse numbers on motor neurons, closely associated with an improvement in gait and balance in old mice. Our results thus describe how the proprioceptive and vestibular systems are modulated by age and exercise, and how these changes affect their input to motor neurons. These findings not only make a strong case for exercise-based interventions in elderly individuals to improve balance, but could also lead to targeted therapeutic interventions aimed at the respective neuronal circuitry.
['Battilana|Fabienne|F|', 'Steurer|Stefan|S|', 'Rizzi|Giorgio|G|', 'Delgado|Ana C|AC|', 'Tan|Kelly R|KR|', 'Handschin|Christoph|C|0000-0003-0603-1097']
D000368:Aged D000375:Aging D000818:Animals D005684:Gait D006801:Humans D007794:Lameness, Animal D008297:Male D051379:Mice D008810:Mice, Inbred C57BL D009046:Motor Neurons D010805:Physical Conditioning, Animal D005082:Physical Exertion D004856:Postural Balance D011434:Proprioception D014722:Vestibule, Labyrinth
balance motor neurons exercise vestibular system training aging motor control proprioceptive system