Motoneuron afterhyperpolarisation duration in amyotrophic lateral sclerosis

Non‐technical summary  Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease of still unknown aetiology, although over 130 years have passed since its first description. Since it is not possible to directly record from motoneurons (MNs) in ALS patients, a significant proportion of the research on ALS takes place in animal models of the disease with specific genetic mutations. However, these results are received with scepticism by many of the clinical researchers, since these mutations are responsible for only about 2% of all human ALS cases. We developed a method to characterise indirectly the human MN afterhyperpolarisation (AHP) duration by analysis of muscular electrical activity. In early stages of ALS muscle impairment we observed substantial shortening of the AHP, which was consistent with the results from acute experiments in ALS animal models. Thus, our study lays a bridge between animal and clinical research that may be relevant for identification of mechanism(s) underlying neurodegeneration in ALS.