Clinical electrophysiological studies suggest that transsynaptic degeneration occurred in the lower motor neurons, while pathological evidence is lacked.
Transsynaptic degeneration of lower motor neurons secondary to upper motor neurons injury plays a role in muscle mass loss.
It has been demonstrated that transsynaptic degeneration occurred wildly in nervous system after cerebral cortex injury, such as cerebellum, [sup] thalamus, [sup],,,,, and substantial nigra, [sup],,, whereas transsynaptic degeneration in motor system remains controversial.
Our work combined the electrophysiological and pathological assessments to investigate the existence transsynaptic degeneration in the motor system, and the relationship between electrophysiology and pathology.
And the pathology results showed that anterior motor neurons significantly decreased, indicating transsynaptic degeneration happened.
We suspected that, the rats have strong self-repair ability and quick recovering from cerebral infarction, although there was decrease in motor neurons due to transsynaptic degeneration in pathological studies at the later stage, the denervated muscle fibers of those motor neuron may be reinnervated by the survived motor neurons, which may lead to the increase in CMAP amplitude and MUNE.
Posterior horn neurons also declined, and even faster than anterior neurons, illustrating that transsynaptic degeneration also existed in the sensory system, which was consistent with the previous study.