Insulin modulates neuronal plasma membrane development in human fetal spinal cord neurons in culture

Abstract

The number of intramembranous protein particles (IMP) in the protoplasmic face of the perikaryal plasma membranes was evaluated in neurons from 9 week-old and 12 week-old human fetal spinal cord in culture. An increased number of IMP was observed in membranes from 12 week-old fetal neurons when compared to membranes from 9 week-old fetal neurons. The addition of insulin (100-2500 μU/ml to the culture media resulted in a significantly increased number of IMP in neuronal membranes. Incubation with glucose (1.5-6 mg/ml) did not modify the number of IMP and glucose did not potentiate the effect of insulin when both glucose (3 mg/ml) and insulin (500 μU/ml) were added to the culture media. The results suggest that insulin may modulate the development of neuronal membranes and that this effect is not mediated by an increased glucose utilization.