A modulating effect of Hygergine on the synaptic plasticity of old rats.

The morphological plasticity of E-PTA stained synaptic junctions was investigated by means of quantitative morphometry in the dentate gyrus supra-granular layer of adult, old and old-Hydergine treated rats. Numerical (Nv) and surface (Sv) density as well as average size of the synapses (S) were the three parameters considered. During aging, Nv and Sv significantly decrease whereas S increases. Hydergine treatment to old rats resulted in a significant increase of Nv and Sv and a significant decrease of S. Present findings are interpreted as a modulating effect of Hydergine on the synaptic plasticity of old rats.