Aim. The goal of the current study was to examine the abnormalities of different subsystems in the default mode network (DMN) in first episode schizophrenia, and to investigate associations between these abnormalities and individual psychopathology. Met...

Introduction: One of the most important unsolved problems in neuroscience is the wiring diagram of the human brain. Different approaches have been used in an attempt to elucidate the connections in the cerebrum in terms of their topographic arrangement [1] as well as in the forms of matrices [2]. Our group has formulated an MRI-based topographic system of human cerebral connectivity [1]. In the present study a list of the connections of each cerebral parcellation unit (PU) has been compiled in matrix form. This connectivity matrix reflects the current body of experimental animal and human data. Methods: To map the cerebral corticocortical, corticothalamic, corticostriatal, corticopontine, hippocampal-cortical and amygdala-cortical connectivity, a meta-analysis of relevant human and non-human primate literature was conducted. Coding of connections was as follows: “1” was assigned to U-fibers and short intragyral and juxtagyral (both intralobar and juxtalobar) connections, “2” was assigned to medium-range in...

Introduction: We studied the remote subcortical effects of cortical damage in twenty-one patients affected by stroke due to embolic occlusion of the left middle cerebral artery. We hypothesized that damage of cortical gray matter would result in decrease of volumes in subcortical remote brain areas such as the thalamus or the corpus striatum that are connected to these cortical regions. Methods: The neuroimaging protocol included rapid volumetric homogenization of the magnetic field (shimming) over the entire brain volume and 3D Morphometric images (GE SPGR inversion recovery weighted T1 images). This protocol was performed successfully in twenty-one patients affected by stroke and twenty normal control subjects. Results and Discussion: We observed volumetric reduction of subcortical gray structures in the patients, especially ipsilateral to the cortical lesions. Here we report the raw data for the thalamus as an example of our findings. In the normal control young adults the mean value of the right thalam...

Anatomical evidence in mammals shows that the mediodorsal thalamus (MD) is a key component within wider prefrontal thalamocortical networks. Accordingly, damage to, or disruption of MD function impairs specific types of complex learning and decision mak...

Precise characterization of cerebellar anatomic subdivisions is required for functional and structural imaging studies of the cerebellum. Volumetric changes during normal development and aging, or related to pathology, emphasize the relevance of morphometric cerebellar cortical analysis. In addition, localization of functional imaging activation in human cerebellar cortex is aided by precise mapping of function onto structural anatomy. We describe a parcellation system of the human cerebellar cortex based upon neuroanatomy which conserves the topographic uniqueness of the individual brain and allows volumetric measurements of specific parcellation units (PUs) of the cerebellar cortex using T1 MRI. METHODS: Based upon a set of fissures, we have defined a system for parcellation of the human cerebellar hemispheres and the vermis into well defined, closed areas or PUs. To this end, eleven fissures and two splines were required. To apply this method to T1-weighted anatomic MR images, cerebellar cortical exteri...

Reduced blue-cone electroretinograms in cocaine-withdrawn subjects correlate with the degree of cocaine craving, suggesting that altered blue cone function might serve as a marker for central nervous system dopaminergic neurotransmitter function. As numerous investigators have applied the blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) method to study stimulus-induced visual cortical activation, we chose to compare the primary visual cortical (V1) BOLD response to red and blue light during altered dopamine activity. Five healthy subjects ingested 2.5 mg oral d-amphetamine and then underwent functional magnetic resonance imaging during retinal stimulation with alternating trials of flashing red or blue light for approximately 50 minutes. Functional images were motion-corrected, and regions in right and left V1 were analyzed by comparing mean BOLD signal of pixels significantly correlated with photic stimulation. A two-sample t-test of averaged right and left V1 BOLD signal r...

The cingulate gyrus, a brain area important for certain cognitive functions, is pathologically involved in the very early stages of Alzheimer’s disease. In this study we investigated the extent of change in this region as a function of healthy aging. Participants consisted of: 1) 41 elderly individuals with normal cognition (mean age: 79.1, range: 67-89); and 2) 27 young adults (mean age: 28.1, range: 22-35). They all underwent a high resolution MRI scan. The cingulate gyrus was segmented from 1.6 mm gapless T1 weighted images using the protocol described by Killiany et al. (Ann Neurol., 2000). For each hemisphere, the volumes of the cingulate gyrus and cortex were derived separately. To correct for individual differences in brain size, the volumes of regions of interest were divided by total intracranial volume. The young participants differed significantly from the old in normalized total (right+left) cingulate gyrus (p<0.001) and cortex (p<0.001) volumes. Further analyses indicated that these age-relate...

Multiple sclerosis (MS) is a neuro-inflammatory and demyelinating disease. Downregulation of neuronal mitochondrial gene expression and activity have been reported in several studies of MS. We have previously shown that hemoglobin-β can signal to the nu...

Objective: The stem of the superior longitudinal fascicle (SLF) was characterized volumetrically and biophysically (in terms of fractional (FI) and lattice anisotropy (LI) indices) in vivo in four patients with left perisylvian ischemic stroke lesions, and in four healthy adult human subjects using DT-MRI. Quantitative analysis was performed anterior to the site of the lesion to assess the integrity and size of SLF, allowing for the identification of potential secondary degeneration changes of this association fiber pathway. Methods: A Siemens Sonata 1.5 Tesla scanner was used. Scans included MP-RAGE T1 scans and echo-planar diffusion tensor-MRI (DT-MRI). The echo-planar based protocol included diffusion tensor imaging to sample the diffusion tensor, D, using a seven-shot EPI technique with TR=200ms, TE=89ms, 36 averages, image matrix=128x128, voxel size=2x2x2mm3, b=1000s/mm2, 60 contiguous coronal slices for a total acquisition time of approx. 13 min, and a SNR of approx. 40. Custom made software and semi...

[11C]-JNJ-42491293 is a positive allosteric modulator (PAM) that was initially developed as a radio-ligand to image metabotropic glutamate 2 (mGlu2) receptors using positron emission tomography (PET) studies. Whereas in vitro binding and in vivo imaging...