Prolonged acetylcholinesterase inhibition and impairment in object recognition memory in rats subjected to chronic hyperprolinemia

Previous studies show that hyperprolinemia impairs spatial memory. Rats received subcutaneous injections of proline (Pro) twice a day at 10 hours intervals from the 6th to the 28th days of age and equivalent volume of 0.9% saline solution (control). The animals were killed 3 hours, 12 hours, or 30 days after the last injection by decapitation without anesthesia to determine acetylcholinesterase (AChE) activity or the animals remained at the animal facility until the 60th day of life to assess the effect of Pro administration on non-spatial memory. Results showed that rats subjected to experimental chronic administration of Pro present a significant non-spatial memory deficit (short- and long-term memory). Prolonged alterations in AChE activity were observed in the hippocampus and cerebral cortex of rats subjected to Pro administration. Data indicate that chronic hyperprolinemia alters AChE activity, interfering in acetylcholine levels, which could participate in inducing the memory deficit observed in hyperprolininemic rats.