Is developmental neuropathology of the motor neurons the key to resolving the mystery in motor neuron diseases?

Recently, genetic analyses on motor neurons diseases have advanced leaps and bounds, but mysteries still remain in the pathogenesis of amyotrophic lateral sclerosis and spinal muscular atrophy. Three papers in this issue of Brain and Development presented intriguing topics on the developmental neuropathology of motor neurons in the spinal cord and brainstem. Neonatal asphyxia experiments in rats indicated the modification of brainstem monoaminergic neuron systems in the development and repair of spinal motor neurons. In the victims of sudden perinatal and infant death, population changes in motor neurons and interneurons in the hypoglossal nucleus were shown to be involved in the disturbed maturation of the respiratory network in the brainstem. The coexistence of hypoglossal hypoplasia and hyperplasia of the area postrema was reported in a case of perinatal hypoxic ischemic encephalopathy. These findings are likely to be a key to resolving the undetermined pathological mechanisms of motor neuron diseases.