Simvastatin improves learning and memory in control but not in olfactory bulbectomized rats

Olfactory bulbectomy (OBX) in a laboratory rodent leads to numerous behavioral deficits and involves cognitive and motor changes that are used to model major depression, but may also be a valuable tool in the study of neurodegenerative disorders like Alzheimer's disease. This experiment evaluated the effects of simvastatin, a cholesterol-lowering drug with putative neuroprotective properties, on OBX-induced behavioral changes. Chronic administration of simvastatin, starting 48 h after surgery, did not have any behavioral effect in OBX rats, as tested in open field, passive avoidance and object-recognition paradigms. In control rats, simvastatin treatment resulted in an improved performance in both the passive avoidance and the object-in-place task. In the present study, simvastatin treatment enhanced cognition in intact rats, but had no effect in OBX rats. These results are in line with the idea that statins may attenuate (early) age-associated cognitive decline in humans.