Functional MRI of neural plasticity and drug effect in the brain

Abstract

Recent advances in magnetic resonance imaging (MRI) have opened up new perspectives for understanding brain function and its plasticity after damage or even in the process of learning and memory. Using functional MRI (fMRI), reorganization of the cortical representation can be detected after the peripheral nerves deafferentation or digit amputation. To detect the more trivial changes during learning and memory, we established two techniques. One is to use manganese as a contrast agent to detect minute reorganization of hippocampal mossy fiber after training with hidden platform in Morris water maze. The other technique detects the synchrony in fMRI signal among neural areas that represents functional connectivity. We demonstrated the spatial memory network can be visualized in water maze trained animal. Furthermore, we showed that synchrony rather than activity in the brain can be modulated by receptor targeted pharmaceuticals, which indicate a different drug mechanism. The translation of these methods will facilitate our understanding of brain plasticity, early diagnosis of dementia, and evaluation of drug efficacy. © 2012 Springer Berlin Heidelberg.