Nerve growth factor receptor immunoreactivity in the cerebellar cortex of aged rats: effect of choline alfoscerate treatment.

The rat cerebellar cortex represents an interesting animal model for the analysis of age-dependent changes in brain microanatomy and function. Moreover, the cerebellar cortex contains detectable amounts of nerve growth factor (NGF) and express NGF receptors, which are sensitive to aging. Previous studies of our group have shown that treatment with choline alfoscerate (alpha-glyceryl-phosphorylcholine) countered the loss of nerve cells and fibers occurring with age in the cerebellar cortex. The present study was designed to assess whether treatment for 6 months with a daily dose of 100 mg/kg of choline alfoscerate has any effect on the expression of NGF receptor immunoreactivity in male Wistar rats of 24 months of age. Twelve-month-old rats were used as an adult reference group. NGF receptor immunoreactivity which was developed in the 3 layers of the cerebellar cortex in adult rats was decreased in the neuropil of the molecular layer and in the cytoplasm of Purkinje neurons of rats of 24 months. The number of NGF receptor immunoreactive Purkinje neurons was also lower in the oldest age group, whereas the NGF receptor immunoreactivity in the cytoplasm of granule neurons was unchanged. Treatment with choline alfoscerate increased NGF receptor immunoreactivity in the molecular layer and in the cytoplasm of Purkinje neurons as well as the number of immunoreactive Purkinje neurons but was without effect on NGF receptor immunoreactivity in the granule neurons. These results suggest that choline alfoscerate treatment may increase the expression of NGF receptors in the rat cerebellar cortex.