Changes In Brain Chemistry Research Articles

Regional energy metabolism during maturation and aging of mouse cerebellum

This chapter focuses on the regional energy metabolism during maturation and aging of mouse cerebellum. To assess age-related changes in brain chemistry in a systematic way, it would be well to avoid the usual sources of variability encountered in sampling brains of individual animals at various ages, yet allow relatively rapid scanning of the total life span of the species. Most physiological and biochemical parameters are close to adult values and many studies of brain development have followed mice only to the age of 30 days. One of the difficulties in assessing development is the variation that is found even among inbred litters. The effect of severe food deprivation can cause profound retardation of brain development. In the late maturational period, following apparent morphological, physiological, and behavioral maturation of the mouse cerebellum, significant age-related metabolic changes can still be found. These changes are sometimes in opposite directions in different regions and might easily be undetected if the whole cerebellum is studied.

Environmental impoverishment, social isolation and changes in brain chemistry and anatomy

A series of experiments, employing a littermate control design, was performed with rats of the Berkeley S 1 strain to answer three questions: (a) What brain effects will be produced by more stringent impoverishment than was employed in former experiments? (b) Will housing animals in pairs in an impoverished environment protect them from the usual cerebral consequences of isolation in an impoverished environment? (c) Is an impoverished environment, with or without isolation, a stressor? Two hundred and sixty-five animals were assigned among four conditions: Environmental complexity and training, social control, isolated in extreme impoverishment, or paired in extreme impoverishment. Some of the largest differences among groups occurred in the ratio of cholinesterase to acetylcholinesterase activity in the cortex. The results demonstrate that (a) the more restricted is the environment, the greater the changes in brain chemistry and anatomy, (b) pairing animals did not protect them from developing cerebral changes similar to those of animals isolated in impoverishment, and (c) there were no indications that isolation or impoverishment are stressors.