Restricted, repetitive behavior is diagnostic for autism spectrum disorder (ASD) and a prominent feature of other neurodevelopmental disorders. Our lab utilizes an inbred mouse strain (C58) that exhibits robust repetitive motor behavior phenotype (verti...

Background: Fragile X Syndrome (FXS) is a neurodevelopmental disorder that is considered to be the most common identified monogenic cause of autism spectrum disorder (ASD) and intellectual disability (ID). FXS is caused by a reduction in the Fragile X M...

The structures of the medial temporal lobe, such as the amygdala, hippocampus, entorhinal cortex and transentorhinal cortex, constitute the locus of some of the earliest anatomical changes in Alzheimer's disease. Because definitive diagnosis of this dis...

Ongoing alpha oscillations might reflect aspects of functional specific perceptual inhibition. In a previous study we found that transcranial alternating current stimulation applied at an individual somatosensory mu alpha frequency (mu-tACS) induces a p...

Therapeutic treatment options for diseases of the central nervous system are greatly constrained by the presence of the blood-brain barrier (BBB). Focused ultrasound (FUS), in conjunction with circulating microbubbles, can be used to induce a targeted a...

1H magnetic resonance spectroscopic imaging (1H MRSI) is a sensitive and early indicator of metabolic nervous system dysfunction. Accounting for spatial dependency of spectroscopic signals will improve 1H MRSI diagnostic precision. Thus, hippocampal and striatal spectra were compared. Methods: Mouse brain 1H MRSI was acquired with a Bruker 7T/21 MRI/MRS system. Spectroscopic images were recorded using 20 X 20 phase encoding over a 20 mm field of view using 1 mm slice thickness, 50 ms TE and 4 s TR. We assessed (Figure L) MRI images corresponding to the center of the selected slice and spectra from single voxels corresponding to the compiled mouse brain regions. Analyses (Figure-R) of the ratios of N-acetyl aspartate (NAA) choline (Cho), myoinostitol (mI), glutamate (Glu) and glutamine (Gln) normalized to the creatine (Cre) peak from within each spectrum were performed. Conclusions: NAA/Cre, Cho/Cre, and mI/Cre are spatially dependent, with reductions from the CA1 to CA3 hippocampal regions. Glu/Cre increas...

OBJECTIVES: Fractional anisotropy value (FA) analysis in diffusion tensor magnetic resonance imaging in various neurological diseases requires presumable allocation of regions-of-interest (ROIs). We proposed a color FA mapping that enables visual estimation without ROI allocation. SUBJECTS and METHODS: Eight patients with Parkinson's disease (PD), six age-matched patients with progressive supranuclear palsy (PSP), and eight age-matched normal subjects underwent diffusion-weighted MRI using 1.5T clinical imager. Derived FA maps of the brains were normalized, and converted into 32-step color FA maps. RESULT: Averaged color FA map of parkinsonian patients showed decrease in not only hypothalamus but also white matters of frontal lobes, while averaged map of PSP patients revealed profound decrease in FA values of most parts of the white matter, compared with those of normal subjects. We confirmed these changes by subtraction method and direct comparison of FA values. DISCUSSION: An overview of FA change derive...

Object recognition is a fundamental mechanism for visually-guided behavior. Functional MRI studies comparing complete images to unrecognizable scrambled versions of those images have shown activation of ventral stream areas, specially of a group of areas known as the lateral occipital complex (LOC). Here we investigated the spatio-temporal dynamics of object recognition by co-registering data from high-density electrical recording (ERPs) and functional magnetic resonance imaging (fMRI). Nine subjects participated in both ERP and fMRI sessions, during which they were presented with blocks of either complete figures (COM), figures in which 50% of the image had been deleted randomly (INCOMP), or scrambled images (SCRAM). FMRI showed the typical LOC activations but also substantial dorsal stream involvement. Comparison of electrophysiological brain activation under the different conditions showed a surprisingly early and significant differential activation of the P1 component (90-120 ms). This earliest modulat...

To understand the mechanism of central nervous system (CNS) fatigue, we investigated the responsiveness of the brain in chronic fatigue syndrome (CFS) patients and in control subjects by using functional magnetic resonance imaging (fMRI). While the subjects were conducting a fatigue-inducing continual visual search task, the responsiveness of the auditory cortices to transient noise reduction of short duration was simultaneously measured. During the fatigue-inducing period, the responsiveness of the auditory cortices was attenuated more rapidly in the CFS patients than in the control subjects. The attenuation speed of CFS patients was significantly correlated with the subjective fatigue sensation just before the MRI session measured by use of a fatigue visual analogue scale. After the fatigue-inducing session, the decrement of responsiveness in the visual cortices was similar between the 2 groups. Hence, CNS fatigue may be characterized by the attenuation of the responsiveness to stimuli non-specific to th...

Event-related functional magnetic resonance imaging was used to investigate the impact of frequency and level of emotional salience on the neural response to word stimuli in the context of a lexical decision task. The participants were presented with a pseudo-randomly ordered sequence of high- and low- frequency neutral and emotional (high negative, low negative and neutral) words obtained from the MRC Psycholinguistic Database, and an equal number of pronounceable non-words, derived from the word stimuli by randomly exchanging one letter. The MRI data were analyzed using the Analysis of Functional Neuroimaging (AFNI) software and consisted of both individual and group level-analyses. Reaction times were greater for lexical decisions involving the low frequency words. Low frequency words, successfully recognized as words, were associated with greater activation in bilateral inferior frontal cortex, left superior frontal gyrus, and insula. We suggest that greater dorsolateral prefrontal activation may be ne...