Stereological estimates of human cortex and whole brain volumes at autopsy reveal only slight age-related changes. Autopsied brains from patients suffering neurological disease, including acquired immunodeficiency syndrome (AIDS) and Alzheimer's disease (AD), show significant loss (atrophy) of cortical and whole brain volumes compared to age-matched controls, with strong correlation to dementia scores in AD (Mouton et al., 1998). Early detection of brain atrophy would improve understanding of the time course of neurodegeneration and accelerate the therapeutic management of these diseases. We used high-resolution magnetic resonance imaging (MRI) to visualize hippocampal and whole brain volumes of mice double transgenic for two mutant proteins associated with AD (amyloid precursor protein and presenilin-1). Young and aged dtg APP/PS1 and wild-type (WT) mice were imaged by spin-echo T1-weighted MRI techniques. Total volumes of hemispheres (Vbrain) and hippocampal formation (VHF) were estimated from systematic...

Williams Syndrome (WS) is a neurodevelopmental disorder caused by a deletion of chromosome 7q11.23. Individuals exhibit striking peaks and valleys in neurocognition that include deficits in visuospatial processing along with relatively preserved language and face processing. These features are associated with distinct variations in neuroanatomy and physiology. In an effort to identify their genetic origins, we have compared 2 atypical cases to WS and to control populations at a highly integrative level, combining studies of molecular structure, volumetric magnetic resonance imaging (MRI), cognition, and event-related potentials (ERPs). We used multicolor FISH with a panel of 45 BACS, PACS and cosmids, PCR of somatic cells hybrids and quantitative Southern blots to identify 80 adults with typical deletions, and 2 adult males with overlapping atypical deletions (one from FKBP6 to CYLN2, and the 2nd from CLDN4 through GTFII-I). Brain structure was determined through MRI studies. Cognition was determined by st...

Goals of study: Event-related functional magnetic resonance imaging was used to explore the interactions of emotion and (within-task) cognitive load using an affective number Stroop task. Method: In this study, two congruent, or alternatively incongruent, numerical displays were bracketed by negative, neutral, or positive IAPS pictures (e.g., four 5s -> picture of snake -> five 4s -> picture of snake). The participants’ task was to compare the numerosities in the two numerical displays and indicate whether the first or the second numerical display represented the greater numerosity. MRI scanning was performed on a 1.5 Tesla MRI scanner. Results: We found a significant emotion by task-load interaction with emotional content (positive as well as negative) modulating the neural response to the incongruent, but not the easier congruent condition. In addition, brain responses to emotional stimuli were modulated by task load. Conclusion: These results indicate that both positive and negative information can inte...

We visualize, for the first time, the profile of structural deficits in the human brain associated with chronic methamphetamine (MA) abuse. Studies of human subjects who have used MA chronically have revealed deficits in dopaminergic and serotonergic systems and cerebral metabolic abnormalities. Using magnetic resonance imaging (MRI) and new computational brain-mapping techniques, we determined the pattern of structural brain alterations associated with chronic MA abuse in human subjects and related these deficits to cognitive impairment. We used high-resolution MRI and surface-based computational image analyses to map regional abnormalities in the cortex, hippocampus, white matter, and ventricles in 22 human subjects who used MA and 21 age-matched, healthy controls. Cortical maps revealed severe gray-matter deficits in the cingulate, limbic, and paralimbic cortices of MA abusers (averaging 11.3% below control; p < 0.05). On average, MA abusers had 7.8% smaller hippocampal volumes than control subjects ( p...

Human social behavior involves multiple sensory exchanges, one of the least understood being olfaction. Functional magnetic resonance imaging (fMRI) and Positron Emission Tomography (PET) studies reveal activation to environmental and household smells i...

Results from previous studies suggest that early deafness in humans leads to compensatory plasticity in remaining intact modalities. Specifically, Finney, Fine & Dobkins (Nature Neuroscience, 2001) used functional magnetic resonance imaging (fMRI) to sh...

Prior studies employing functional magnetic resonance imaging (fMRI) report cortical activation associated with target detection in both frontal and parietal areas. In contrast, studies using scalp electroencephalography (EEG) report large P300 event-re...

Functional magnetic resonance imaging experiments have demonstrated in humans that anticipation/mobilization of instrumental responses for various rewards recruits the ventral striatum to a greater degree than anticipation of responding for no incentive...

Introduction To gain a clear understanding of the mechanisms underlying Blood Oxygenation Level-Dependent functional magnetic resonance imaging in the brain, we need to quantify the structural organization and density of blood vessels. The goal of our c...

Most studies using functional Magnetic Resonance Imaging (fMRI) in paediatric temporal lobe epilepsy (TLE) have focused on language lateralisation and neglected to assess memory. Early onset seizures interfere with the normal process of hemispheric late...