RNA content and volume of motor neurons in amyotrophic lateral sclerosis. I. The cervical swelling.

The content of RNA and the volume of motor neurons isolated from the lateral portion of the cervical swelling were examined in six control and six amyotrophic lateral sclerosis (ALS) cases obtained at autopsy. The mean volume of motor neurons in the ALS group did not differ significantly from the values obtained in the controls. However, in two cases of ALS with extensive neuronal loss and relatively long duration of disease most of the remaining cells were atrophic. The content of RNA in motor neurons averaged 300 micromilligram in the ALS group compared to 513 micromilligram in the control cases. The reduction in RNA content in the ALS group is approximately 42% and is statistically significant.