PROJECT 4 - DTI AND MTI STUDIES IN SCHIZOPHRENIA

这个子项目是众多研究子项目之一

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Understanding of the neuropathology of schizophrenia has been advanced by numerous magnetic resonance imaging (MRI) studies over the past decade, which confirms the presence of structural brain abnormalities in schizophrenia, including volume alterations of the ventricles, frontal lobe, medial temporal lobe, superior temporal gyrus, inferior parietal lobe and subcortical brain regions (for review, see1). The distributed pattern and number of abnormalities observed in schizophrenia are consistent with a disturbance of connectivity within and between brain regions and a white matter abnormality underlying this disturbed neural connectivity. Indeed, prefrontal grey matter volume has been highly correlated with volume reductions in the amygdala-hippocampus complex and superior temporal gyrus in the brains of schizophrenic patients2. While numerous conventional MRI studies have reported grey matter abnormalities in schizophrenia1, relatively few in comparison have specifically assessed and reported modest but significant white matter volume decreases in schizophrenic brains3-9. Newer techniques such as diffusion tensor imaging (DTI), which allows inferences of the coherence of white matter tracts (anisotropy), and magnetization transfer imaging (MTI), which provides a putative measure of myelin in the brain (magnetization transfer ratio; MTR), extend our understanding of white matter deficits from merely assessing volumetric loss to providing preliminary imaging evidence for decreased organization in white matter tracts and subtle reductions in the myelin content of schizophrenic brains. These findings are also consistent with microscopic studies revealing ultrastructural alterations of myelinated fibers from the prefrontal cortex of schizophrenic patients10-12. In addition, demyelinating diseases such as adolescent onset metachromatic leukodystrophy and multiple sclerosis are associated with behavioral and cognitive disturbances similar to that observed in schizophrenia. The purpose of this study is to learn more about different brain areas in people who have been diagnosed with schizophrenia.