Structural changes induced by cytidine-5'-diphosphate choline (CDP-choline) chronic treatment in neurosecretory neurons of the supraoptic nucleus of aged CFW-mice

The influence of chronic administration of cytidine-5'-diphosphate choline (CDP-choline), a precursor of the membrane lipid phosphatidylcholine, was studied in neurosecretory neurons (NSNs) of the supraoptic nucleus (SON) of aged mouse hypothalamus. Animals were treated with CDP-choline from 12 months of age until 26 months. They were studied for both morphologic and morphometric features. The results obtained were compared to those of an age-matched control group. There was evidence of differences between NSNs of the control group and those of the CDP-choline group which showed neuronal hypertrophy. This size increase was mainly attributed to the increment of cellular protein synthesis machinery, rough endoplasmic reticulum (RER) and Golgi complexes. Furthermore there was an increase in the number of neurosecretory granules (NSGs) in the CDP-choline group. In addition, there were no tertiary lysosomes in the treated animals. Moreover, the percentage of NSN membrane that was not covered by glial prolongations, increased from about 2% in the control group to 12%, in the CDP-Choline treated group. These changes suggested an activation of the cellular processes for neurohormone synthesis in the experimental group. Furthermore, these NSNs displayed lipid droplets in their cytoplasm. The possible relationship between CDP-choline and NSNs activity is discussed.