Early postnatal maternal deprivation in rats induces memory deficits in adult life that can be reversed by donepezil and galantamine

Early postnatal maternal deprivation is known to cause long‐lasting neurobiological effects. Here, we investigated whether some of the cognitive aspects of these deficits might be related to a disruption of the cholinergic system. Pregnant Wistar rats were individually housed and maintained on a 12:12 h light/dark cycle with food and water freely available. The mothers were separated from their pups for 3 h per day from postnatal day 1 (PND‐1) to PND‐10. To do that, the dams were moved to a different cage and the pups maintained in the original home cage, which was transferred to a different room kept at 32 °C. After they reached 120–150 days of age, maternal‐deprived and non‐deprived animals were either sacrificed for brain acetylcholinesterase measurement, or trained and tested in an object recognition task and in a social recognition task as described by Rossato et al. (2007) [Rossato, J.I., Bevilaqua, L. R.M., Myskiw, J.C., Medina, J.H., Izquierdo, I., Cammarota, M. 2007. On the role hippocampal synthesis in the consolidation and reconsolidation of object recognition memory. Learn. Mem. 14, 36–46] and Lévy et al. (2003) [Lévy, F., Melo. A.I., Galef. B.G. Jr., Madden, M., Fleming. A.S. 2003. Complete maternal deprivation affects social, but not spatial, learning in adult rats. Dev. Psychobiol. 43, 177–191], respectively. There was increased acetylcholinesterase activity in hippocampus and perirhinal cortex of the deprived animals. In addition, they showed a clear impairment in memory of the two recognition tasks measured 24 h after training. Oral administration of the acetylcholinesterase inhibitors, donepezil or galantamine (1 mg/kg) 30 min before training reversed the memory impairments caused by maternal deprivation. The findings suggest that maternal deprivation affects memory processing at adulthood through a change in brain cholinergic systems.