12-May-2009, TAU-MR club, Tel Aviv University <br>
<b>High Resolution MRI of Enriched Environment Induced Structural Brain Changes</b><br>
Ory Levy, Faculty of Life Sciences, Department of Neurobiology, TAU<br>
<br>
<i>Abstract:</i><br>
<HR>

Alzheimer's disease (AD) is a progressive dementia related disease accompanied by a major effect of white matter loss. One suggested therapeutic and preventive approach to the white matter loss is the induction of neurogenesis. In addition to ""classical"" approaches of neurogenesis induction by biochemical and surgical approaches, the environmental enrichment paradigm is a successful paradigm to induce neurogenesis by means of creating a more complex environment. In this study we examined the usefulness of MRI as an imaging tool to evaluate environmental enrichment without requiring the sacrifice of the research animals and thus enabling a follow-up of the study. For the research we used 12 C57BL/6J mice at the age of weaning, the mice were divided into two groups of 6 each (control and enrichment). The enriched mice were kept 4 months in enrichment following by one month in a regular environment. The mice were scanned at the end of the enrichment and one month after. The MRI included a DTI protocol from which the fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were extracted. These parameters are correlated with microstrcutral features of the tissue such as density and organization. Our results showed that MRI enabled recovering known areas of effect (the hippocampus). Furthermore, the use of the DTI contributed more insight by pointing out more areas, including the corpus callosum, the caudate\putamen and the thalamus in which significant differences were found to exist after environmental enrichment. For the DTI analysis, the ADC showed significant difference in the frontal hippocampus and in the paraventricular thalamic nucleus, the FA showed significant difference in the frontal corpus callosum. Our study demonstrates that MRI allows following on morphoological tissue changes induced by enriched environment. In addition, it allows in vivo whole brain analysis which provides a more comprehensive evaluation of tissue changes