Age-dependent changes in gp75LNGFR (low-affinity nerve growth factor receptor) immunoreactivity in the rat cerebellar cortex.

The expression of gp75LNGFR (low-affinity receptor of the nerve growth factor (NGF) family of neurotrophins) immunoreactivity was studied in the cerebellar cortex of male Wistar rats of 3 months (young), 12 months (adult) and 24 months of age using immunohistochemical techniques and a monoclonal antibody against rat-gp75LNGFR. The percentage of Purkinje neurons displaying gp75LNGFR immunoreactivity (IR), and the intensity of gp75LNGFR IR in the cytoplasm of Purkinje and granule neurons, and in the neuropil of molecular layer of the cerebellar cortex were determined by quantitative image analysis and microdensitometry. The number of Purkinje neurons displaying gp75LNGFR IR and the intensity of gp75LNGFRIR in the cytoplasm of Purkinje neurons was significantly higher in rats of 12 months of age in comparison with 24- and 3-month-old rats. No significant changes were observed in the intensity of gp75LNGFRIR in the granule neuron layer of young, adult and old rats. In the molecular layer, the highest gp75LNGFRIR was found in young animals. It was reduced as a function of age. The present results show that changes in gp75LNGFRIR observed as a function of age affect to a different extent the three layers of the rat cerebellar cortex.