REGIONAL CHANGES IN RAT-BRAIN CHOLINE-ACETYLTRANSFERASE AND ACETYLCHOLINESTERASE ACTIVITY RESULTING FROM UNDERNUTRITION IMPOSED DURING DIFFERENT PERIODS OF DEVELOPMENT

The severity of mental changes in malnourished children is related to both the period of development when the malnutrition occurs and the amount of environment stimulation. The effect of imposing protein undernutrition during the period of gestation or postweaning period and protein-energy undernutrition during the suckling period on cholinergic enzyme activity was investigated in the rat. Six different dietary treatments were given and the activity of ChAc [choline acetyltransferase EC 2.3.1.6], ChE [cholinesterase] and AChE [acetylcholinesterase EC 3.1.1.7] determined in the forebrain, brainstem and cerebellum of male rats on day 49. Undernutrition imposed during gestation, suckling or postweaning all resulted in changes in cholinergic enzyme activity. The direction and degree of change of enzyme activity depended on the period when undernutrition was imposed as well as the brain region. In the forebrain ChE and AChE activities were altered, in the brainstem, ChAc, ChE and AChE activities were altered, and in the cerebrellum ChAc activity was altered. The effect on the activity of the individual cholinergic enzymes was complex and was not the same in the different regions of the brain or even for the same brain region exposed to undernutrition during different periods of development. These results along with earlier work indicate that cholinergic enzyme activity in brain and undernourished rats can be altered by both the period of development when undernutrition is imposed and the amount of environmental stimulation.