Environmental enrichment is a natural means by which the brain can make itself more resilient against disease; however, its mechanisms remain incompletely defined. Environmental enrichment consists of increased social, physical and intellectual activity (i.e., learning), which can reduce brain injury by more than 50%. This is greater than any treatments now available for all degenerative disorders of brain. Thus, the mechanisms by which the environment makes the brain stronger have immense clinical and basic scientific importance. The goal of this study was to determine how signaling within and among neural cells from environmental enrichment results in neuroprotection. The important aspects of environmental enrichment (i.e., increased physical, social and intellectual activity) lead to synaptogenesis, neurite branching, gliosis and improved learning and memory. We have shown that environmental enrichment is neuroprotective against kainic acid injury, a model of temporal lobe epilepsy. In order to model learning in vitro, we used chemical long-term potentiation (cLTP), which induces long-term changes in synaptic strength and transmission thought to be the cellular basis of learning and memory. We have shown that there is a decrease in injury from 45% in controls to 10% from cLTP. This would implicate that learning is neuroprotective in vitro as well as in vivo. We also examined the effects of TNF-a preconditioning on injury. Tumor necrosis factor-a (TNF-a) is a cytokine that is injurious at high doses, yet nutritive at low levels (Wilde et al. 2000). These results show that learning-both in vitro and in vivo-can be neuroprotective.
Michalene Otis,’08 Dubuque, IA
Major: Biochemistry and Molecular Biology
Sponsor: Barbara Christie-Pope