The Expression of Neural Cell Adhesion Molecule in Dopaminergic Neuron of the Rat Substantia Nigra Compact During Normal Aging

Aim:To observe the expression changes of neural cell adhesion molecule(NCAM)and tyrosine hydroxylase(TH)in dopamine(DA)neurons of the rat substantia nigra compact(SNc)during normal aging,and to discuss the mechanism of the change.Methods:24 male healthy SD rats were divided into two groups:4～5 months group and above 24 months group.Routine paraffin sections were made for TH and NCAM immunohistochemical staining,and expressions of the proteins were detected by Western blot.The number of positive neurons was counted under microscope and the gray scales of electrophoresis strips were analyzed.Results:There was coexpression of TH with NCAM in dopamine neurons of SNc,and the total number of TH-positive neurons and the amount of TH-protein had no change with aging(P0.05),but the number of TH-positive neurons decreased in the caudal of substantia nigra compact of aged rats(P0.05),meanwhile,the expression of NCAM decreased in aged rats(P0.05),although there was no decrease in every fragment(P0.05).Conclusion:The product of DA descended in substantia nigra compact during normal aging,moreover,NCAM may be participated in the descent.