Abstract
Fasciculations are characteristic features of amyotrophic lateral sclerosis (ALS), suggesting abnormally increased excitability of motor axons. Previous nerve excitability studies have shown reduced axonal potassium currents in ALS patients that may contribute to the hyperexcitability and thereby generation of fasciculations. To clarify changes in axonal ion channel expression in motor axons of ALS, we performed immunohistochemistry of potassium and sodium channels in the C7 and L5 ventral/dorsal roots obtained from five autopsy cases of sporadic ALS. Compared to controls, the immunoreactivity of potassium channels (Kv1.2) was markedly reduced in the ventral roots, but normal in the dorsal roots of all the ALS patients. Nodal sodium channel expression was not significantly different in ALS patients and control subjects. Our results show prominently reduced expression of axonal potassium channels, and provide the neuropathological and biological basis for decreased accommodative potassium currents in motor axons of ALS patients. The axonal hyperexcitability would lead to generation of fasciculations, and possibly enhances motor neuron death in ALS.
Original language | English |
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Pages (from-to) | 149-153 |
Number of pages | 5 |
Journal | Experimental Neurology |
Volume | 232 |
Issue number | 2 |
DOIs | |
Publication status | Published - 2011 Dec |
Externally published | Yes |
Keywords
- Amyotrophic lateral sclerosis
- Axonal hyperexcitability
- Fasciculation
- Motor axon
- Potassium channel
ASJC Scopus subject areas
- Neurology
- Developmental Neuroscience