The endocannabinoid anandamide [ N -arachidonoylethanolamine (AEA)] is thought to function as an endogenous protective factor of the brain against acute neuronal damage. However, this has never been tested in an in vivo model of acute brain injury. Here, we show in a longitudinal pharmacological magnetic resonance imaging study that exogenously administered AEA dose-dependently reduced neuronal damage in neonatal rats injected intracerebrally with the Na+/K+-ATPase inhibitor ouabain. At 15 min after injury, AEA (10 mg/kg) administered 30 min before ouabain injection reduced the volume of cytotoxic edema by 43 ± 15% in a manner insensitive to the cannabinoid CB1receptor antagonist SR141716A. At 7 d after ouabain treatment, 64 ± 24% less neuronal damage was observed in AEA-treated (10 mg/kg) rats compared with control animals. Coadministration of SR141716A prevented the neuroprotective actions of AEA at this end point. In addition, (1) no increase in AEA and 2-arachidonoylglycerol levels was detected at 2, 8...

Independent component analysis (ICA) has been used in functional imaging studies to evaluate the spatial extent and temporal profiles of task related brain activity (e.g. Kansaku et al., 2005). The particular merit of the ICA is that it does not require...

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...

The first in vivo magnetic resonance study of experimental cerebral malaria is presented. Cerebral involvement is a lethal complication of malaria. To explore the brain of susceptible mice infected with Plasmodium berghei ANKA, multimodal magnetic resonance techniques were applied (imaging, diffusion, perfusion, angiography, spectroscopy). They reveal vascular damage including blood-brain barrier disruption and hemorrhages attributable to inflammatory processes. We provide the first in vivo demonstration for blood-brain barrier breakdown in cerebral malaria. Major edema formation as well as reduced brain perfusion was detected and is accompanied by an ischemic metabolic profile with reduction of high-energy phosphates and elevated brain lactate. In addition, angiography supplies compelling evidence for major hemodynamics dysfunction. Actually, edema further worsens ischemia by compressing cerebral arteries, which subsequently leads to a collapse of the blood flow that ultimately represents the cause of dea...

High-fidelity 3D neuro-histological reconstructions of whole brains with light microscopic resolution have not yet been achieved for human. Our laboratory previously standardized a tape-transfer based, high-throughput method for 3D digital histology in ...

While the pathological changes induced by the loss of dopamine innervation in the basal ganglia by Parkinson's disease are well studied, little is known about functional changes in the neural circuitry of this area during normal aging. Accordingly we have analyzed age-associated changes in the basal ganglia of behaviorally characterized, awake rhesus monkeys, using pharmacological MRI to map responses to dopaminergic stimulation. Apomorphine, a mixed D1/D2 dopamine receptor agonist, significantly reduced neural activity in the substantia nigra (SN) of young adult rhesus monkeys, while evoking little change in aged animals. Compared to young animals, both apomorphine and amphetamine (an indirect D1/D2 dopamine receptor agonist) significantly increased activation of the aged rhesus globus pallidus externa (GPe). In addition, the aged animals showed decreased activity in the putamen in response to amphetamine administration. The changes in SN, GPe and putamen activation are consistent with the concept that ba...

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,...

Background: There has been increasing interest in detailed hippocampal subfield morphometry in cognition, aging and disease research using in vivo MRI. However, research on in vivo morphometry is hampered by lack of a definitive reference model describi...

Postmortem studies indicate a temporal sequence of primary allocortical and secondary neocortical degeneration during Alzheimer disease (AD) progression. Hippocampus (HC) atrophy correlates with allocortical neuronal degeneration and atrophy of the corpus callosum (CC) reflects loss of intracortical projecting pyramidal neurons in neocortex. First, we wanted to determine the temporal sequence and rate of degeneration of HC and CC in AD. Second, to answer the question, whether rates of atrophy were correlated with rates of cognitive decline and third, whether both markers could be proposed as potential morphological parameters for mapping drug effects on brain structure in longitudinally studied AD patients and healthy control subjects. MRI-derived measures of CC and HC were compared between 27 clinically diagnosed AD patients and 28 age- and gender-matched healthy control subjects. Rates of CC and HC atrophy were determined in 21 AD patients and 10 control subjects studied longitudinally. We found mean rel...

The re-emergence of task-related activation patterns during awake rest has been reported to play a role in memory consolidation and perceptual learning. This study aimed to test whether such reactivation occurs in the primary sensorimotor cortex following a visuomotor task. During functional magnetic resonance imaging (fMRI) scanning, 42 healthy participants (13 women and 29 men) learned visuomotor tracking, while a rotational perturbation was introduced between the cursor position and joystick angle. This visuomotor task block was interleaved with a control block, during which participants passively viewed a replay of their previously performed cursor movements. Half of the participants used their right hand, whereas the other half used their left hand to control the joystick. Resting-state scans were acquired before and after the visuomotor task sessions. A multivariate pattern classifier was trained to classify task and control blocks and was then tested on resting-state scans collected before and after...