Insulin-like growth factor II receptors in human brain and their absence in astrogliotic plaques in multiple...

Insulin-like growth factor (IGF) II receptors were studied in human adult brain by using autoradiography with [125I]IGF-II. Receptors were found to be widely distributed throughout all neuronal regions. The highest densities were found in plexus choroideus, granular layer of the cerebellar cortex, gyrus dendatus and pyramidal layer of the hippocampus, striatum, and cerebral cortex. White matter was devoid of IGF-II receptors. We also examined [125I]IGF-II binding in six plaques of multiple sclerosis, which were characterized by a dense network of astrocytes. We were unable to detect IGF-II receptors in any of the astrogliotic plaques, suggesting that IGF-II receptors in human brain are not involved in astrogliosis. The regional variations in neuronal distribution of IGF-II receptors suggest involvement of IGF-II in functions associated with specific neuronal pathways.