Objective To observe the changes of the brain function during reading recovery by using functional MRI (fMRI),and to provide the experimental data in elucidating the mechanism on the recovery of reading and language function.Methods fMRI was performed in a native Chinese patient with pure alexia on the 45 th and 130 th day after the onset,respectively.Three kinds of Chinese characters were presented during the scan and the patient was asked to make the judgement weather he could recognize the characters or not.The brain activation maps were acquired after postprocessing,and the activated location and volume were compared between the first and second experiments.Results In both experiments,Broca area,Wernicke area,and the right extrastriate were significantly activated,while the left extrastriate around the lesion was markedly activated only in the second experiment,and the volume of activation in the right extrastriate in the second experiment was about 3 times as large as that in the first experiment.Conclusion The left extrastriate cortex is one of the key areas responsible for reading function in the brain.The recovery of reading function can be compensated in contralateral corresponding cortical area,or it can be the result of reorganization in ipsilateral peri-lesion cortex.Both mechanisms may simultaneously play important roles in reading recovery.

OBJECTIVESTo identify the cortical areas engaged during Chinese word processing using functional magnetic resonance imaging (fMRI) and to examine the reliability and reproducibility of fMRI for localization of functional areas in the human brain.

METHODSFMRI data were collected on 8 young, right-handed, native Chinese speakers during performance of Chinese synonym and homophone judgment tasks on two different clinical MRI systems (1.5 T GE Signa Horizon and 1.5 T Siemens Vision). A cross correlation analysis was used to statistically generate the activation map.

RESULTSBroca's area, Wernicke's area, bilateral extrastriate, and ventral temporal cortex were significantly activated during both the synonym and homophone activities. There was essentially no difference between results acquired on two different MRI systems.

CONCLUSIONSFMRI can be used for localizing cortical areas critical to Chinese language processing in the human brain. The results are reliable and well reproducible across different clinical MRI systems.

Adult ; Cerebral Cortex ; physiology ; Female ; Humans ; Language Tests ; Magnetic Resonance Imaging ; Male ; Reproducibility of Results

OBJECTIVETo quantitatively analyze the temporal and spatial pattern of RhoA expression in injured spinal cord of adult mice.

METHODSA spinal cord transection model was established in adult mice. At 1, 3, 7, 14, 28, 56 and 112 days after the surgery, the spinal cords were dissected and cryosectioned for RhoA/NF200, RhoA/GFAP, RhoA/CNPase or RhoA/IBA1 double fluorescent immunohistochemistry to visualize RhoA expressions in the neurons, astrocytes, oligodendrocytes and microglia. The percentages as well as the immunostaining intensities of RhoA-positive cells in the parenchymal cells were quantitatively analyzed.

RESULTSRhoA was weakly expressed in a few neurons and oligodendrocytes in normal spinal cord. After spinal cord injury, the percentage of RhoA-positive cells and RhoA expression intensity in the spinal cord increased and peaked at 7 days post injury (dpi) in neurons, oligodendrocytes and astrocytes, followed by a gradual decrease till reaching a low level at 112 dpi. In the microglia, both the RhoA-positive cells and RhoA expression intensity reached the maximum at 14 dpi and maintained a high level till 112 dpi.

CONCLUSIONTraumatic spinal cord injury can upregulate RhoA expression in the neurons as well as all the glial cells in the spinal cord. RhoA expression patterns vary with post-injury time, location and among different parenchymal cells in the injured spinal cord.

Animals ; Astrocytes ; metabolism ; Female ; Mice ; Mice, Inbred Strains ; Microglia ; metabolism ; Neuroglia ; metabolism ; Neurons ; metabolism ; Spinal Cord ; metabolism ; Spinal Cord Injuries ; metabolism ; rho GTP-Binding Proteins ; metabolism