In an era where magnetic resonance imaging (MRI) is common place around the world, more and more cases of extreme alterations in brain morphology appear in the literature (Lancet 2007: 370:262) and popular press. Usually caused by early hydrocephalus, l...

We used functional magnetic resonance imaging (fMRI) to investigate human visual pathways underlying perception of three-dimensional (3-D) structure from motion induced by two-dimensional (2-D) rotational or translational motion. We compared significant brain activity regions between 2-D and 3-D conditions in each motion stimulus by using a block paradigm. In each experimental scan, subjects viewed a rotational or translational stimuli. The 3-D condition was presented for 16 seconds, followed by the 2-D condition for 16 seconds. Each condition was alternately repeated 12 times. The fMRI was done at 3T. For 3-D structure-from-motion (SFM) by the rotational motion stimulus, the parieto-occipital area, especially V3A, the intraparietal sulcus (IPS) and the inferior parietal lobule (IPL), activated. On the other hand, for 3-D SFM by the translational motion stimulus, significant activation was not observed in the parieto-occipital area. It may be suggested that the separated pathways contribute to 3-D SFM by r...

Lipopolysaccharide (LPS), a potent endotoxin, derived from the cell wall of gram-negative bacteria causes severe inflammation in the brain. Neuroinflammation is associated with several neurodegenerative diseases, including stroke, Parkinson’s disease, Alzheimer’s disease, multiple sclerosis and amyotrophic lateral sclerosis. The hallmark of brain inflammation is the activation of microglial cells that produce proinflammatory and neurotoxic factors, including cytokines and free radicals. In the present study we correlate magnetic resonance imaging (MRI) and immunohistochemistry applying different neuronal and glial markers to analyse neurodegenerative processes in a LPS-mediated model of neuroinflammation. As demonstrated by MRI, unilateral injection of LPS into the striatum of rats led to structural changes at different time points following endotoxin application. In parallel, immunfluorescence with Fluoro-Jade B showed an increased number of degenerating neurons in the striatum 24 hours, 3 and 7 days afte...

Introduction: Previous research has identified two major ways in wich attention can be directed to an object: voluntary or automatic. The purpose of this study is to identify the brain networks involved in voluntary attention using event-related functio...

Magnetic Resonance Imaging and functional MRI developed in the last decades into a tool used in a multitude of scientific studies and medical applications, numbers rising. A very frequently applied technique here is based on the blood oxygenation depend...

Wire microelectrodes made of platinum-iridium, tungsten, or other alloys, are commonly used for the study of the Central Nervous System in animal models. Normally, they do not represent a risk in Magnetic Resonance Imaging (MRI), but they may produce significant image artifacts. Besides some advantages, such as batch fabrication, channel density, high reproducibility, and precise dimensions, silicon based microelectrodes have a low magnetic susceptibility signature and their thickness is smaller than the smallest dimension of a MRI voxel, even under standard micro-MRI techniques. Therefore, the detection of this type of microelectrode using MRI is challenging, especially for in vivo studies and at low magnetic fields. We address this problem and present a method for the in vivo detection of silicon microelectrodes using MRI at 2 Tesla. We apply concepts of micro-MRI, phase imaging, and susceptibility weighted imaging to detect sub-voxel size features that accurately define the shape of the electrodes. Firs...

Cross-sectional magnetic resonance imaging (MRI) studies have long hypothesized that the brain in children with autism undergoes an abnormal growth trajectory that includes a period of early overgrowth; however, this has never been confirmed by a longitudinal study. We performed the first longitudinal study of brain growth in toddlers at the time symptoms of autism are becoming clinically apparent using structural MRI scans at multiple time points beginning at 1.5 years up to 5 years of age. We collected 193 scans on 41 toddlers who received a confirmed diagnosis of autistic disorder at ∼48 months of age and 44 typically developing controls. By 2.5 years of age, both cerebral gray and white matter were significantly enlarged in toddlers with autistic disorder, with the most severe enlargement occurring in frontal, temporal, and cingulate cortices. In the longitudinal analyses, which we accounted for age and gender effect, we found that all regions (cerebral gray, cerebral white, frontal gray, temporal gray...

Introduction: Our previous work has shown dynamic changes that occur in the subacute to chronic phase after unilateral cervical spinal cord injury (SCI) in rats using magnetic resonance imaging (MRI). Here we show how this lesion develops during the acu...

Introduction: Traditionally, OCD has been described as a pathological condition in which the patient experiences intrusive, repetitive and uncomfortable thoughts that can become disabling (obsessions). Later, they resort to certain behaviors or rituals ...

We are developing fMRI to characterise common homeostatic and reward pathways of drugs and natural regulators of appetite. As a proof of concept, an anorexic dose of the 5-HT2C/1B receptor agonist m-chlorophenylpiperazine (mCPP; 3mg/kg s.c.) was used to compare fMRI with expression of the c-Fos protein. mCPP was injected into satiated male Sprague-Dawley rats, which were then anaesthetised and perfused transcardially 90 min later to allow immunocytochemistry. In a separate experiment, rats underwent fMRI in a 7 Tesla magnet for 70 min under α-chloralose anaesthesia. A T2* weighted gradient echo was used to record brain volumes every 70 s. Results, analysed using SPM99 software, determined brain areas with significant changes in Blood Oxygenation Level Dependent (BOLD) contrast. Both methods detected activity in areas of the limbic system: nucleus accumbens, medial hypothalamus, bed nucleus of the stria terminalis, and thalamus. fMRI detected activation in the pontine nuclei, the hippocampal formation and s...