| 1.Research Institution | Fukui Medical University | |
| 2.Research Area | Life Sciences | |
| 3.Research Field | Higher Brain Functions | |
| 4.Term of Project | FY 1997 〜 FY 2001 | |
| 5.Project Number | 97L00203 | |
| 6.Title of Project | Studies on Plasticity of Higher Function in Human Brain Using PET and Functional MRI |
| Name | Institution,Department | Title of Position |
| Yoshiharu, Yonekura | Fukui Medical University, Biomedical Imaging Research Center | Professor |
8.Core Members
| Names | Institution,Department | Title of Position |
| Norihiro, Sadato | National Institute of Physiological Sciences, Department of Cerebral Cortex | Professor |
| Yasuhisa, Fujibayashi | Fukui Medical University, Biomedical Imaging Research Center | Professor |
9.Summary of Research Results
|
The brain is a dynamically changing structure responding to continuous alterations of the
peripheral input and internal signal communication. The present project utilized noninvasive
neuroimaging techniques, such as positron emission tomography (PET) and functional magnetic
resonance imaging (MRI), to depict functional reorganization of the brain due to deaffentation, and
examined the plastic changes in relation to learning and aging proces. Functional MRI studies in the
blind subjects demonstrated that the tactual information process is taken in the association visual
cortex and further transferred to primary visual cortex in the subjects who lost their vision before the
age of 15. Similar studies of sign languages showed that the sign activated the auditory cortex of the
deaf subjects. These findings may provide biological basis for training in the handicapped, and also
shed lights on how the brain organizes itself to integrate multimodal sensory input for communication.
On the other hand, studies in the aged subjects revealed that parietal and temporal cortices were not
utilized for the picture encoding task, and the neural activities in the hippocampus and the amygdala
were also decreased during the face recognition task. These data suggested the aging-related
alterations of higher brain. Furthermore, the present project extended to the imaging of a rapidly
changing pattern accompanying normal human brain maturation by means of functional MRI on
infants. In order to examine the molecular basis of the neuronal plasticity, a new imaging technique
of positron radionuclide labeled tracers was introduced and applied to the fresh brain slices of the
small animals, which successfully demonstrated the metabolic changes due to hypoxia and/or
ischemia. In conclusion, noninvasive functional neuroimaging technique could be a powerful tool to
investigate the functional reorganization and developmental neurophysiology. |
10.Key Words
(1)higher brain function、(2)brain activation study、(3)plasticity
(4)PET、(5)MRI