are stimulated by long-duration subthreshold or suprathreshold
stimuli. This axonal superexcitability leads to blockage of each third
applied stimulus in the case of ALS2 and to blockage of each second
applied stimulus in the case of ALS3 as a result of the repetitive
fi ring caused by the previous applied stimulus. Superexcitability
of the nodal and internodal axolemma, based on the continuous
activation and reactivation of the ionic (mainly Na
+
) channels in
these compartments, can be regarded as a prelude to neuron death.
And this is probably the reason for motor neuron degeneration in
this disease.
Simulated Demyelinating Neuropathies and Neuronopathies 93