Lipreading enhances the perception of spoken language by combining audible speech with the corresponding visible articulation movements. To evaluate the neural substrates of the cross-modal effect of the lip movement on speech identification, we underwent functional MRI on 28 normal volunteers. Tasks were the vowel identification based on the speech or lip movement. The reaction time (RT) of auditory vowel identification was 103 ms longer than that of the visual one. RT of the auditory vowel identification was shortened when the concordant lip movement was presented simultaneously, whereas elongated by discordant one. RT of the visual vowel identification was unchanged when the concordant speech was presented simultaneously, whereas elongated by discordant one. Therefore, cross-modal enhancement in the vowel identification was exerted from visual to auditory modalities, not vice versa. During auditory tasks, the orbitofrontal cortex was active only during the simultaneous presentation of the concordant lip...

Real-time in vivo imaging of grafted neural stem progenitor cells (NSPCs) is a significant advance toward understanding the fate of NSPCs after grafting. We have previously demonstrated the utility of bioluminescence imaging system for tracking grafted primary NSPCs in the injured spinal cord. Here we investigated the use of magnetic resonance imaging (MRI) to track the contrast agent-labeled primary NSPCs in the injured spinal cord. Primary NSPCs derived from E14 rodent striatum were labeled with iron oxides particles. Magnetically labeled NSPCs exhibited a similar growth rate to unlabeled cells and did not affect normal cellular differentiation. MRI was performed on an either 11.7-T Bruker Advance Spectrometer or 7.0-T Bruker Pharmascan. in vitro MRI showed that one cluster consisting of 200 single cells led to an MRI contrast sufficient to allow reliable detection. in vivo experiment, spinal cord injury was induced by Multicenter Animal Spinal Cord Injury Study (MASCIS) impactor at T10 level and NSPCs w...

Introduction - Amyotrophic lateral sclerosis (ALS) is an horrific illness with rapid degeneration of motor neurons. Monitoring motor circuitry in ALS patients is difficult due to the inability of patients to perform even simple motor tasks at later stages. We utilized pharmacologic magnetic resonance imaging (phMRI) of a passive amphetamine challenge for longitudinal study of motor cortex/dopaminergic circuitry in FALS rats. Methods - Rats expressing SOD1G93A and wild-type (WT) littermates were studied. PhMRI experiments were run using a contrast agent to sensitize images to relative blood volume (rCBV), then amphetamine (2.5 mg/kg, i.v.) was injected. ROI analysis was used to assess regional rCBV changes. Five rats were scanned pre-symptomatically (85+/-28 days) and again after partial hind-limb paralysis (131+/-13 days). Results - The response to amphetamine produces a pattern that involves sensorimotor cortex (SMCx), caudate/putamen (CPu), and medial prefrontal cortex (MPFCx). The average rCBV (%) in CP...

Sex-specific behaviors are in part based on hormonal regulation of brain physiology. This functional magnetic resonance imaging (fMRI) study demonstrated significant differences in activation of hypothalamic-pituitary-adrenal (HPA) circuitry in adult women with attenuation during ovulation and increased activation during early follicular phase. Twelve normal premenopausal women were scanned twice during the early follicular menstrual cycle phase compared with late follicular/midcycle, using negative valence/high arousal versus neutral visual stimuli, validated by concomitant electrodermal activity (EDA). Significantly greater magnitude of blood oxygenation level-dependent signal changes were found during early follicular compared with midcycle timing in central amygdala, paraventricular and ventromedial hypothalamic nuclei, hippocampus, orbitofrontal cortex (OFC), anterior cingulate gyrus (aCING), and peripeduncular nucleus of the brainstem, a network of regions implicated in the stress response. Arousal (...

NVM is an open source software tool for making precise neuroanatomical measurements in MRI. SegMentor is a feature of this software that explicitly defines and embeds measurement methods into the tool by providing on-line, context-sensitive instructions and definitions, and also by assisting in making the measurements. SegMentor records, plays, and allows viewing and editing of scripts that provide information to the user and also control the rest of the program. We present the results of a study to analyze the effectiveness of SegMentor for increasing the reliability and decreasing the time necessary for making precise neuroanatomical measurements. By analyzing the same brain scans with and without using SegMentor, we show improvements in both accuracy and efficiency: using SegMentor increases the repeatability and decreases the cost to obtain quantitative MRI brain measurements.

The validity of movement kinematics during functional magnetic resonance imaging (fMRI) experiments is poorly controlled due to technical constraints of the imaging environment. To reliably identify brain areas related to simple and complex movement sequences as well as learning related motor performance changes it is important to control carefully for type, speed and accuracy of the performed movement. We present a method designed to record kinematics of drawing-like upper limb movements during functional magnetic resonance imaging. The recording system consists of a translucent plastic board, a plastic pen with fiber optics and a halogen light power source, a CCD camera, a video monitor and a PC with a video grabber card. Our method yields high temporal and spatial resolution of the recorded movement kinematics during fMRI scanning. Control experiments using a commercially available digitizer tablet show a) the reliability of the kinematic data recorded during functional magnetic resonance imaging and b)...

Fractal analysis has been used to quantify a wide range of complex and irregularly shaped objects in basic biology and medicine. In this study we measured the white matter (WM) fractal dimension (FD) based on human MR brain images. Coronal MR head images were collected from 6 healthy young (26.8±3.4) and 6 elderly (74.2±2.6) subjects using a 1.5T Siemens Vision scanner and a three-dimensional Turboflash imaging sequence (TR/TE = 11.4/4.4ms, flip angle = 10°). Slice thickness was 2 mm, in-plane resolution was 1 x 1 mm2. The head images were then resampled via trilinear interpolation to be 1 mm in thickness. The brain was segmented from the resampled head images using the BET tool in the FSL package. The WM was then segmented from the brain images using the FSL FAST tool and recorded as a binary (black & white) images. A 3-D thinning method was applied to the binary images to obtain skeletons of the WM. A box-counting dimension was adopted to define the FD of the WM skeleton which repeatedly meshed different...

Parkinson's disease is characterized by impaired initiation of movement, muscular rigidity and tremor clinically. In traditional Korean medicine, acupoints LR3 (Taechung) and GB34 (Yangneungcheon) have been used to treat such movement related disorders. Recently, we showed the neuroprotective and movement promoting effects of these acupoints with 6-OHDA induced Parkinson's disease rat model. In this study, we observed acupuncturing on (1) LR3 and (2) GB34 respectively, or on (3) both acupoints together activate movement-related brain areas with functional MRI (fMRI). Ten right-handed subjects participated in these fMRI experiments using a blocked paradigm on a 3T MRI scanner. In the group of LR3, medial frontal gyrus (Left ;L), fusiform gyrus (L), cerebellum (L), pons (L) and thalamus (Right ;R) were activated. In the group of GB34, middle frontal gyrus (R), lingual gyrus (L), cerebellum (R), parahippocampal gyrus (L), insula (L), cingulate gyrus (R, BA24), posterior cingulate gyrus (L, BA29), claustrum (R...

Directing attention to some acoustic features of a sound has been shown repeatedly to modulate the stimulus-induced neural responses. On the contrary, little is known about the neurophysiological impact of auditory attention when the auditory scene remains empty. We performed an experiment in which subjects had to detect a sound emerging from silence (the sound was detectable after different durations of silence). Two frontal activations (right dorsolateral prefrontal and inferior frontal) were found, regardless of the side where sound was searched for, consistent with the well established role of these regions in attentional control. The main result was that the superior temporal cortex showed activations contralateral to the side where sound was expected to be present. The area extended from the vicinity of Heschl's gyrus to the surrounding areas (planum temporale/anterior lateral areas). The effect consisted of both an increase in the response to a sound delivered after attention was directed to detect ...

The aim of study was to identify potential mechanisms of neurodegeneration by correlating image analysis of brain structures and immunocytochemical analysis of cholinergic pathways. The study was performed in transgenic mice that overexpress either normal human APP (amyloid precursor protein) or SOD1 (superoxyde dismutase 1) or a combination of both genes. Neuropathological studies were performed with T2 magnetic resonance imaging. Multislice axial and sagittal sequences were acquired in a Brucker Biospec (7 Tesla) with spin-echo imaging (TE 65ms, slice thickness 0.40 mm, data matrix 192x128). Following image analysis of these sequences, 3D construct of various brain structures were performed. Statistical comparison of brain regions volumes was performed between various mice. As nitric oxide (NO) may affect cholinergic neurons development, we investigated the morphology of neurons expressing ChAT or NADPH-diaphorase in the brain of transgenic mice. Heavily stained neurons were found in cholinergic regions ...