Neuronal involvement in muscular atrophy

When muscles lose their nerve connection, they shrink rapidly. This atrophy happens faster than if the muscle was just not used, like when someone is bedridden. This review discusses how the nervous system normally keeps muscles healthy and what goes wrong when the nerve connection is lost, leading to muscle wasting. One key change in muscles after nerve damage is that their outer membranes become more leaky. This leakiness is due to new channels appearing on the muscle cell surface, specifically hemichannels made of connexins. The review examines how these channels contribute to the muscle atrophy process. The nerve normally sends signals to the muscle, which keeps the muscle from expressing these connexin channels. The signals include molecules like acetylcholine and neurotrophic factors. The review explores how these signals might work to maintain normal muscle function and prevent the expression of connexin channels.

• 1
  Denervation-induced muscle atrophy is reduced in muscles lacking connexins 43 and 45, suggesting these channels play a key role in the atrophy process.
• 2
  Electrical stimulation can reverse muscle wasting due to paralysis, highlighting the critical role of muscle contraction in suppressing atrophy signals.
• 3
  Connexins are absent in normal adult skeletal muscle but reappear in muscles undergoing regeneration or after denervation, mediating key signals for atrophy.