Pilocarpine prevents age-related spatial learning impairments in rats

The cholinergic pathways are intimately involved in the learning and memory process and disruption of this system produces impairments in many learning and memory models. Converging lines of evidence support the idea that there is an age-related decline in learning and memory in animals and this decline is strikingly similar to memory changes that occur when the cholinergic system is compromised. The purpose of this work was to evaluate whether a single administration of the muscarinic receptor agonist Pilocarpine (Pilo) could prevent the age-related learning impairment in rats. Three groups of animals received Pilo (300 mg/kg, i.p.), at 3 months of age, and the animals that did not show Status epilepticus were submitted to the water maze task 1 or 21 months after or once a month from the 4th to 24th month of age. The results showed that Pilo did not interfere with learning abilities 1-month after treatment nor in animals that were submitted to the test once a month. In addition, the animals treated with Pilo and submitted to the task 21 month after performed as well as control young rats in the training and in the testing sessions, while a marked learning impairment was detected in control old rats. These results indicate that a single administration of Pilo might prevent the age-related learning impairments in rats on a spatial task in the water maze. (C) 2004 Elsevier B.V. All rights reserved.