Stress-related effects on neuronal morphology and choline acetyltransferase activity in the hippocampus

The effects of semi-chronic stress on neuronal morphology and choline acetyltransferase were studied by injecting rats with dexamethasone. It was found that in the dexamethasone-treated rats the choline acetyltransferase activity had increased in the area where the fibers from the perforant pathway synapse with the granular cell layer of the dentate gyrus and also where the mossy fibers of the granular cell layer leave the dentate gyrus. In the fibers of same area, an increase in their intensity and amount was detected in the dexamethasone-treated rats. The elevated levels of cortisol or (corticosterone in rats) when one is under semi-chronic stress could have an affect on the acetylcholine synthesis and mossy fiber plasticity in the hippocampus.