Imaging on the binding of FITC-Insulin with Insulin Receptors in cortical neurons of Rat

It has been identified that insulin was present in the central nervous system (CNS) with some types of action there, and it exerted important actions within the brain and functions as neuropeptide. Insulin should bind with insulin receptors (IR) to perform its functions, so it is important to study the binding of insulin with IR in neurons. A direct imaging method was developed by fluorescence microscopy. HepG2 cells were firstly selected to be the model for methodological study, the results showed that insulin could bind with IR at the membrane of the studied cells after incubated 1 minute with the cells. In order to show the binding of insulin with IR in neurons, the cultured cortical neurons of rat were selected as representative. It was found that insulin could bind with IR at the membrane of the neurons, and IR distribute not only on the somas, but also on the neurites. Using fluorescent imaging to directly detect the binding of insulin with IR in neurons could be promising for further study of insulin functions in brain. It is rarely reported the direct imaging on the binding of insulin with IR of neurons by microcopy system in live cells