Chronic environmental stress on the development of MAO and COMT in discrete brain region

Summary Newborn rats were chronically submitted to visual, motion, and acustic stimuli (environmental stress) up to 4 months of age. The stress increased MAO activity of midbrain, cortex, cerebellum, hypothalamus and hippocampus, whereas COMT activity was decreased as early as after 7 weeks of stress in cortex and hypothalamus, and later in medulla, midbrain, cortex and cerebellum. Both activities returned to normal 10 days after the end of the stress. The first developmental period appeared to be rather refractory to the environmental stimulation. The differences in stress-induced alteration of MAO and COMT might be related to different subcellular localization and different maturational schedule of two enzymes.