Effect of pre- and postnatal protein-calorie undernutrition on RNA-content in rat motor neurons.

Changes in the RNA-content of isolated anterior horn motor neurons from the 7th cervical segment were studied during the postnatal development of pre- and postnatally undernourished, and normally nourished rats. The motor neurons of the anterior horn were isolated by micromanipulation from Carnoy-fixed sections. The neuronal RNA-content was determined by microchemical methods according to Edström (1964). The observation was made that moderate pre- and postnatal undernutrition does not alter the normal RNA-accumulation in anterior horn motor neurons during the preweaning period. After weaning the cellular RNA incorporation decreases but again reaches normal values at the age of 39 days. The present results are compared with those of a previous study (Haltia 1970) in which rats were severely undernourished postnatally.