Dynamic interplay between H-current and M-current controls motoneuron hyperexcitability in amyotrophic lateral sclerosis.
Cell Death Dis
; 10(4): 310, 2019 04 05.
Article
in En
| MEDLINE
| ID: mdl-30952836
ABSTRACT
Amyotrophic lateral sclerosis (ALS) is a type of motor neuron disease (MND) in which humans lose motor functions due to progressive loss of motoneurons in the cortex, brainstem, and spinal cord. In patients and in animal models of MND it has been observed that there is a change in the properties of motoneurons, termed neuronal hyperexcitability, which is an exaggerated response of the neurons to a stimulus. Previous studies suggested neuronal excitability is one of the leading causes for neuronal loss, however the factors that instigate excitability in neurons over the course of disease onset and progression are not well understood, as these studies have looked mainly at embryonic or early postnatal stages (pre-symptomatic). As hyperexcitability is not a static phenomenon, the aim of this study was to assess the overall excitability of upper motoneurons during disease progression, specifically focusing on their oscillatory behavior and capabilities to fire repetitively. Our results suggest that increases in the intrinsic excitability of motoneurons are a global phenomenon of aging, however the cellular mechanisms that underlie this hyperexcitability are distinct in SOD1G93A ALS mice compared with wild-type controls. The ionic mechanism driving increased excitability involves alterations of the expression levels of HCN and KCNQ channel genes leading to a complex dynamic of H-current and M-current activation. Moreover, we show a negative correlation between the disease onset and disease progression, which correlates with a decrease in the expression level of HCN and KCNQ channels. These findings provide a potential explanation for the increased vulnerability of motoneurons to ALS with aging.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Aging
/
KCNQ Potassium Channels
/
Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels
/
Superoxide Dismutase-1
/
Cortical Excitability
/
Amyotrophic Lateral Sclerosis
/
Motor Neurons
Type of study:
Prognostic_studies
Limits:
Animals
Language:
En
Journal:
Cell Death Dis
Year:
2019
Document type:
Article
Affiliation country:
Australia