Professor Marian C. Diamond

Department of Integrative Biology

Presently Dr. Diamond's lab is interested in learning about the various factors that influence some mammalian forebrain structures and functions, especially the cerebral neocortex. In particular, the lab studies effects of enriched and impoverished experiential environments, aging, and immune responses.

Previous experiments in Dr. Diamond's lab have investigated five basic factors responsible for keeping the brain healthy and active during the lifespan. The experiments have been conducted primarily in male and female rats and have included measurements of brain cortex thickness, cell number, and number and length of dendrites. The first factor is an optimal diet which is as vital to the brain as it is to the body as a whole. Particularly important is good nutrition during infancy and childhood to optimize development of the nerve cells and their branches. The second factor in maintaining a healthy brain is exercise. The third factor includes newness and challenging the brain. The brain needs new challenges -- as in enriched and changing environment -- to develop and remain a healthy functioning organ. The fourth factor is a strong immune system. The immune system is extremely important to our health at all ages and certainly it is critical to successful aging. From animal studies, the dorsal and lateral frontal cortex is related to the functioning of the immune system. The relations between brain and immune system are a continuing topic of research. The fifth factor is love and nurturing. Many studies in animals (handling, petting, etc. from early age) and in humans (daily kindness) are important factors in maintaining good brain health and thereby a long and successful life.

Another question investigated in Dr. Diamond's laboratory: What happens if the brain is overstimulated? In this case, a stressing environment is created rather than an enriched one and the result is a decrease in the size of the brain cortex. These ongoing experiments suggest that children in school must learn in an environment with more enrichment than stress.

Current studies of Dr. Diamond investigate Enrichment in Action in a Cambodian orphanage to evaluate how the five factors of optimal environment can counteract the effects of environmental stress to which the local children have been, and continue to be, exposed.