Acetylcholine concentrations in the developing brain appear to affect emotionality and mental capacity in later life.

A decrease of the acetylcholine concentration in the brain of infantile rats was induced by maternal deprivation in neonatal life, which was associated with emotional and mental ill-effects in later life. The decreased acetylcholine concentration in the infantile brain as well as the permanent emotional and mental ill-effects, which were produced by neonatal deprivation, could be prevented by neonatal administration of the acetylcholinesterase inhibitor pyridostigmine. These findings suggest that acetylcholine can be considered as an important, environment-dependent local organizer of the brain.