Fatigue is an extremely debilitating condition in older adults. It is associated with increased mortality and decreased quality of life. Despite the significant negative impact of fatigue, we know very little about its actual cause. Currently, there are...

Gadolinium chelates are widely used as contrast media for magnetic resonance (MR) imaging in both clinical diagnostic and pre-clinical studies. Recent reports have shown that repeated administrations of Gadolinium-based contrast agents (GBCAs) may cause...

The designers of Melodic Intonation Therapy (MIT) have hypothesized that the method’s therapeutic benefits to non-fluent aphasic patients are due to a gradual recruitment of right hemispheric language regions for the production of speech. In order to examine such potential neural plasticity effects, we used functional magnetic resonance imaging (fMRI) to examine the neural basis of spoken and melodically intoned words in a severely non-fluent aphasic patient both pre and post 4 weeks of MIT. Images were acquired on a 3T GE MRI scanner, using a sparse temporal sampling technique that takes advantage of the inherent delay in the cerebrovascular response to neural activity. Whole-brain acquisitions (taking 1.75s) were conducted every 15 seconds, immediately after each vocalization, thus avoiding maximum head movement artefacts and also avoiding any scanner noise interference with the stimuli presentation and recording of the vocalizations. Four different experimental conditions were employed: spoken words, me...

Objective: To better understand mechanisms for the antidepressant effect of 1 night’s PSD in patients with current major depression. Hypothesis: Change in depressed patients’ ventral anterior cingulate perfusion will correlate with antidepressant response to PSD. Methods: 17 unmedicated unipolar outpatients (entry baseline 17-item Hamilton Depression Rating Scale (HDRS17) > 16, M/F 5/12, 42.8 + 9.7 years) & 8 controls (M/F 4/4, 35.0+9.5 years) received 3 nights (adaptation, baseline, & PSD, during which they had to remain awake beginning at 3 am) polysomnography in the sleep laboratory. Approximately noon after the baseline & PSD nights, subjects received anatomical & perfusion magnetic resonance imaging (MRI) using pulsed arterial spin labeling, with baseline & PSD blocks in randomized counterbalanced order. Data were analyzed using Analysis of Functional NeuroImages (AFNI)2.56b. Stripped brains were segmented by fitting a 3-compartment Gaussian mixture model to the intensity histogram. Resulting gray mat...

Functional MRI is a non-invasive technique that indirectly detects areas of neuronal activity by observing local changes in blood oxygen. Until recently fMRI has been used only for brain imaging, however, it has since been applied to the spinal cord (spinal fMRI). The relationship between areas of fMRI activity and areas of neuronal activity must be verified by comparison with gold standards in order for spinal fMRI to become more widely accepted. In the present study we compare areas of fMRI activity with areas of extracellular field potentials during noxious electrical stimulation of the hind paw in rats. Halothane-anesthetized rats were placed supine on a quadrature surface coil tuned and matched to 300 MHz. Six, 2 mm thick slices were centred on the vertebra and intervertebral discs between T12 and L1. Three functional imaging experiments on each animal were performed using electrical stimulation (~ 7 mA) delivered by two silver needle electrodes inserted subcutaneously in the dorsal surface of the rig...

Advancements in development of effective pain-relief therapies in acute and chronic pain conditions are of utmost importance to alleviate the suffering of the patients and lift the socio-economic burden of the disorders that involve nociceptive system. ...

The injection of kainic acid (KA) into rat elicits brain damages, including hippocampus, which mimic human temporal lobe epilepsy. Electrophysiological studies evidenced that KA induces epileptiform seizures first in hippocampal CA3 within 1 hr and then propagates to CA1 and other limbic structures. To gain further understanding of the hippocampal activation underlying KA-induced seizures, the aims of the present study are (1) to employ high resolution diffusion-weighted imaging (DWI) and T2-weighted imaging (T2WI) at high magnetic field (7 Tesla) to investigate the temporal evolution of hippocampal abnormalities induced by KA and (2) to investigate whether KA-induced CA3 neuronal activity can be detected using manganese (Mn2+)-enhanced MRI. DWI, T2WI and T1-weighted imaging (T1WI) were acquired before and 2 hr, 1 day¡V7 days after KA intravenous injection. The results showed that, in the dendrites of CA3 pyramidal cells, the hyperintensities of DWI and T2WI were both observed within 2 hr, indicating the f...

Vascular dysfunction is increasingly recognized in the pathophysiology of Alzheimer’s disease (AD), and measures of vascular dysfunction can be evaluated using cerebrospinal fluid (CSF) and imaging-based biomarker approaches. A clinical need exists to i...

Previous research has shown that with age and disease, the integrity of grey matter structures decline. One such measure of grey matter integrity is cortical thickness, where lower values represent thinning of the cortical surface. Given that cognitive ...

Background and Objective: Currently, there is no in vivo detection method for Alzheimer’s Abeta amyloidosis is available clinically. This study is to develop amyloid-specific in vivo imaging compounds for detecting and monitoring Alzheimer's disease Abeta amyloidogenesis. Methods: A novel amyloid-targeting Gadolinium (Gd) metal complex- Gd-XH1 has been designed, synthesized, and chemically characterized. MRI measurements (3T magnetic field strength) were made for solution mixes of Gd-XH1 complex and Abeta40/42 peptides, human serum albumin (HSA), or AD mouse and human brain tissue extracts filled in 4.5-mL hollow polypropylene plastic spheres (phantoms). The effects of Gd-XH1 on longitudinal (T1) magnetic relaxation rates were reported. Gd-DTPA was used as control MRI contrast imaging agent. We have also performed some preliminary studies on rodent models using Gd-XH1. Results: MRI phantom experiment shows that T1 decreases as the Abeta peptide concentration increases. There were little T1 signal changes w...