Cortical hyperexcitability drives dying forward amyotrophic lateral sclerosis symptoms and pathology in mice

Abstract

Degeneration of both upper motor neurons in the brain and lower motor neurons in the spinal cord defines amyotrophic lateral sclerosis (ALS), but how they are linked in ALS pathophysiology is unclear. Here, we uncover a cortical origin of neurodegeneration in ALS mediated by upper motor neuron hyperexcitability. Chronic hyperexcitability of upper motor neurons induced by excitatory chemogenetics in healthy adult mice induced progressive motor deficits, weakness and core pathological hallmarks of ALS, including upper motor neurons loss, synaptic pathology, corticospinal tract degeneration and reactive gliosis. Importantly, upper motor neuron hyperexcitability and loss were sufficient to drive..