In order to further advance our understanding about MRI signal changes due to formalin fixation over time, we measured different MR properties such as T1- and T2-relaxation, diffusion-based fractional anisotropy (FA), mean diffusivity (MD), and myelin w...

Early childhood is a critical period showing experience-dependent changes in brain structure and function. The complex link between the structural connectivity (SC) and functional connectivity (FC) of the brain is of particular interest. However, its relationship with both age and attention in early childhood is not well understood. In this study, children between the ages of 4 and 7, and at a 1 year follow-up visit, underwent neuroimaging (diffusion-weighted and passive-viewing functional magnetic resonance imaging) and assessments for selective, sustained, and executive attention. We examined regional graph metrics and SC–FC coupling of the structural and functional networks. Partial least squares was used to investigate longitudinal brain measure changes and cross-sectional associations with age and attention. We observed longitudinal changes in functional graph metrics and age-related decreases in SC modularity. Region-wise graph analyses revealed variable brain–behavior relationships across the brain,...

Intracerebral hemorrhage (ICH) is a significant cause of mortality throughout the world. Management of ICH in terms of clot lysis and iron scavenging after the initial insult is critical for the recovery and appropriate imaging methods to detect and fol...

Over the last 15 years, the number of studies using high-resolution MRI to examine the structure and function of human hippocampal subfields has soared. However, the ability to compare findings across studies has been hampered by substantial differences...

It is suggested that the monkey inferior temporal (IT) cortex plays a key role in color information processing. Although single-unit recordings in monkeys have found that there are many color-selective neurons in the IT cortex, it is still unclear how t...

Magnetic resonance elastography (MRE) is a noninvasive medical imaging technique that can quantitatively assess brain viscoelastic mechanical properties to provide sensitive measurements of neural tissue health. Previous work has shown that global brain...

We tested the hypothesis that activation of voltage-gated Na+ channels and glutamate (GLU) release underlies functional magnetic resonance imaging (fMRI) signal based on the blood oxygenation level dependent (BOLD) during somatosensory activation. The BOLD fMRI experiments were performed at 7 Tesla on α-chloralose anesthetized rats undergoing forepaw stimulation before and for successive times after the application of lamotrigine (LTG), which is a neuronal voltage-gated Na+ channel blocker and GLU release inhibitor. LTG led to a time-dependent attenuation of the BOLD fMRI signal increase in somatosensory cortex during forepaw stimulation of 72% between 60-90 min after administration. BOLD signal during forepaw stimulation declined significantly from 7.2±1.0% before LTG to 2.0±2.3% (P<0.0016), while the volume of the activated region declined from 5.9±0.9 mm3 to 0.9±1.0 mm3 (P<0.0001). These results strongly suggest that voltage-gated Na+ channels and GLU release are involved in the BOLD fMRI response durin...

In non-human mammals, the neuropeptide oxytocin is a key mediator of complex emotional and social behaviors, including attachment, social recognition, and aggression. Oxytocin reduces anxiety and impacts on fear conditioning and extinction. Recently, oxytocin administration in humans was shown to increase trust, suggesting involvement of the amygdala, a central component of the neurocircuitry of fear and social cognition that has been linked to trust and highly expresses oxytocin receptors in many mammals. However, no human data on the effects of this peptide on brain function were available. Here, we show that human amygdala function is strongly modulated by oxytocin. We used functional magnetic resonance imaging to image amygdala activation by fear-inducing visual stimuli in 15 healthy males after double-blind crossover intranasal application of placebo or oxytocin. Compared with placebo, oxytocin potently reduced activation of the amygdala and reduced coupling of the amygdala to brainstem regions implic...

Is the left inferior frontal cortex (LIFC) a single functional region, or can it be subdivided into distinct areas that contribute differently to word processing? Here we used transcranial magnetic stimulation (TMS) to investigate anterior and posterior LIFC when the meaning and sound of words were being processed. Relative to no stimulation, TMS of the anterior LIFC selectively increased response latencies when participants focused on the meaning of simultaneously presented words (i.e., synonym judgments) but not when they focused on the sound pattern of the words (i.e., homophone judgments). In contrast, the opposite dissociation was observed in the posterior LIFC, where stimulation selectively interfered with the phonological but not the semantic task. This double dissociation shows functionally distinct subdivisions of the LIFC that can be understood in terms of separable corticocortical connections linking the anterior LIFC to temporal pole regions associated with semantic memory and the posterior LIF...

INTRODUCTION: Continuous Arterial Spin Labeling (CASL) is a non-invasive MRI technique that measures absolute CBF with long-term stability suitable for following slow variations as might occur during the development of Alzheimer's Disease (AD). The main...