A single high dose of dexamethasone increases GAP-43 and synaptophysin in the hippocampus of aged rats.

摘要: The administration of dexamethasone, a synthetic glucocorticoid receptor agonist, has been reported to modulate cognitive performance in both animals and humans. In the present study, we demonstrate effects single high dose dexamethasone on expression distribution synaptic plasticity-related proteins, growth-associated protein-43 (GAP-43) synaptophysin, hippocampus 6-, 12-, 18- 24-month-old rats. Acute treatment significantly altered GAP-43 at posttranslational level by modulating levels phosphorylated proteolytic GAP-43-3 fragment. effect was most pronounced hippocampi aged animals. total protein increased only dexamethasone-treated animals, concomitant with decrease calpain-mediated proteolysis. Moreover, introducing gray co-occurrence matrix method, form texture analysis, were able reveal subtle differences pattern synaptophysin hippocampal subfields that not detected Western blot analysis alone. Therefore, current study demonstrates, through novel combined approach, affects