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PubMed1998

Differentiation of metabolic concentrations between gray matter and white matter of human brain by in vivo 1H magnetic resonance spectroscopy.

Differentiation of absolute metabolite concentrations between gray and white matter in the occipital region of normal human brain was performed by in vivo localized single-voxel 1H magnetic resonance spectroscopy at 1.5 Tesla with long echo time (136 ms). With the combination of image segmentation between white and gray matter and cerebrospinal fluid, signal compensation of T1 and T2 effects, tissue water signal as the internal concentration reference, as well as compensation by different water contents in gray and white matters, it was determined that the levels of N-acetylaspartate (NAA), creatine and/or phosphocreatine (Cr), and choline-containing compounds (Cho) in gray matter were significantly higher than in white matter. The averaged NAA, Cr, and Cho concentrations in gray matter were 11.0, 9.7, and 1.9 mM/liter, respectively, in comparison with 7.5, 5.2, and 1.6 mM/liter in white matter. These results suggest that precise composition of white and gray matter and cerebrospinal fluid is necessary to avoid partial voluming effect in a single voxel and to accurately quantify the metabolite concentrations.

Adult↗
PubMed1986

Effects of neonatal undernutrition of rats on the synthesis of phosphatidylcholine and phosphatidylethanolamine by microsomes from gray matter and white matter.

Undernutrition of rats during the suckling period produces deficits of glycerophospholipids in white matter but not in gray matter. The synthetic enzymes, CDPethanolamine:diacylglycerol phosphoethanolaminetransferase (EC 2.7.8.1) and CDPcholine:diacylglycerol phosphocholinetransferase (EC 2.7.8.2), were assayed in washed microsomal fractions from moderately and severely undernourished rats at 21 days of age. Deficits in brain weight were 14 and 31%, respectively. The transferase activities in white matter were more than 2-fold greater than in gray matter. Moderate undernutrition has less effect on total transferase activities but Km values were increased for CDPethanolamine with phosphoethanolamine transferase and for CDPcholine and dicaprin with phosphocholine transferase. Severe undernutrition produced by feeding the dams a diet with 4% protein gave deficits for phosphoethanolamine transferase of 52 and 55% and for phosphocholine transferase of 40 and 46% for gray matter and white matter, respectively. These results are consistent with the deficits of glycerophospholipids in white matter. Additional factors, such as synthetic rates in vivo and a reduction of turnover rates, must be sought for the sparing of the glycerophospholipid content of gray matter during undernutrition.

Animals↗
PubMed2006

Both global gray matter volume and regional gray matter volume negatively correlate with lifetime alcohol intake in non-alcohol-dependent Japanese men: a volumetric analysis and a voxel-based morphometry.

BACKGROUND: Non-alcohol-dependent heavy drinkers, as well as alcohol-dependent individuals, show brain atrophy. The purpose of this study was to evaluate whether there are correlations between global and regional gray matter volumes and the lifetime alcohol intake using volumetric analysis and voxel-based morphometry (VBM) among Japanese non-alcohol-dependent male individuals. METHODS: High-resolution three-dimensional magnetic resonance images were acquired from 405 Japanese non-alcohol-dependent male individuals. The collected images were normalized, segmented for volumetric analysis, and additionally smoothed for VBM. For volumetric analysis, the partial correlation coefficient was estimated between the gray matter ratio, which represents the percentage of gray matter volume in the intracranial volume, and the lifetime alcohol intake adjusted for the age of each subject. Multiple regression analysis was performed among regional gray matter volume, lifetime alcohol intake, and age using VBM. RESULTS: Volumetric analysis revealed that gray matter ratio showed a negative correlation with the lifetime alcohol intake adjusted for age (p=0.059, partial correlation coefficient=-0.091). The VBM revealed that the gray matter volumes of the bilateral middle frontal gyri showed a significant negative correlation with the lifetime alcohol intake adjusted for age and systolic blood pressure (left side, p=0.006, Z=4.77; right side, p=0.023, Z=4.45, and p=0.046, Z=4.27). CONCLUSIONS: Our study suggests that non-alcohol-dependent Japanese male individuals show that both global gray matter volume and regional gray matter volume have negative correlations with the lifetime alcohol intake. Our study may contribute to clarifying the mechanism underlying the brain structural changes because of alcohol influence in healthy non-alcohol-dependent individuals.

Adolescent↗
PubMed2000

White matter volumes and periventricular white matter hyperintensities in aging and dementia.

OBJECTIVE: To determine the relationship between MRI periventricular white matter hyperintensities, cerebral white matter volumes, neuropathologic findings, and cognitive status in aged individuals. BACKGROUND: The significance of periventricular white matter hyperintensities seen on MR images in aged individuals remains controversial. The Nun Study is a longitudinal cohort aging study in which all 678 initially enrolled participants agreed to autopsy neuropathologic examination. METHODS: We used MRI to measure white matter volumes of the cerebral hemispheres in 52 formaldehyde-fixed brains for correlation with white matter and neocortical pathology, postmortem MRI observations, and cognitive measures. RESULTS: Reduced white matter volume is associated with dementia, but periventricular white matter hyperintensities were not related to white matter volume, stroke, or dementia. CONCLUSIONS: Our results do not support the hypothesis that periventricular hyperintensities seen on MR images have deleterious consequences in these aged individuals.

Aged↗
PubMed1999

High spatial resolution 1H-MRSI and segmented MRI of cortical gray matter and subcortical white matter in three regions of the human brain.

High-resolution MR imaging and spectroscopic imaging were used to study differences in proton spectra between cortical gray matter and subcortical white matter in 23 normal volunteers using a 1.5 T scanner and surface coil receivers. A point-resolved spectroscopy (PRESS) volume with an 8 x 8 x 8 phase-encoding matrix was used to acquire over 1900 0.09-0.2 cc spectral voxels. The high-resolution (0.7 x 0.7 x 0.8 mm3 or 0.8 x 0.8 x 1 mm3) images were corrected for the surface coil reception profile and segmented into cerebrospinal fluid (CSF) and gray and white matter to correlate with the spectra. The data showed that N-acetyl aspartate (NAA) and creatine (Cr) were higher in the gray matter than in the white matter (NAA(g/w) = 1.4+/-0.36, Cr(g/w) = 1.4+/-0.41). Choline was significantly lower in the gray matter of the occipital lobe than in the white matter (0.73+/-0.19), but not significantly different in the other regions. NAA/Cho was found to be significantly higher in the occipital lobe than in the left frontal or vertex regions.

Adult↗
PubMed1995

Cerebral white matter in the centrum semiovale exhibits a larger N-acetyl signal than does gray matter in long echo time 1H-magnetic resonance spectroscopic imaging.

Long echo time (272 ms) 1H magnetic resonance spectroscopic imaging was used to measure the relative magnitudes of the N-acetylaspartate (NAA) signal in a variety of anatomically defined brain structures (centrum semiovale, thalamus, medial frontal cortex, and genu of the corpus callosum) composed primarily of gray matter or white matter. Six normal young adult humans aged 30-40 were studied. With a 95% level of statistical confidence, the white matter in the centrum semiovale (CSO) produced a more intense NAA signal than did the gray matter in the thalamus and the frontal cortex. Differences between the white matter regions were also noted. The CSO white matter's NAA signal yielded a larger NAA signal than did the white matter of the genu of the corpus callosum. Possible reasons for the anatomical variation in the cerebral NAA signal intensity are discussed.

Adult↗
PubMed2005

An evaluation of white matter injury after spinal cord ischemia in rats: a comparison with gray matter injury.

We quantitatively assessed both gray and white matter injury after spinal cord ischemia in rats, and the relationship between the magnitude of gray and white matter injury was determined. Twenty-five male rats were anesthetized with isoflurane, and spinal cord ischemia (SCI) was induced by balloon intraaortic occlusion combined with hypotension. The animals were randomly allocated to one of the following three groups: animals with SCI for 12 min (SCI-12; n = 8), 15 min (SCI-15; n = 9), or those with sham operation (n = 8). Twenty-four hours after reperfusion, hindlimb motor function was assessed using the Basso-Beattie-Bresnahan scale scoring. Gray matter damage was assessed on the basis of the number of normal neurons in the ventral horn. White matter damage was assessed on the basis of the extent of vacuolation and amyloid precursor protein immunoreactivity in the ventral and ventrolateral white matter. There were significantly less normal neurons in the SCI-15 group compared with those in the SCI-12 and sham groups (P < 0.05). There was a significant positive correlation between the Basso-Beattie-Bresnahan scores and the number of normal neurons. The percentages of vacuolation areas in the SCI-15 group were significantly larger compared with those in the SCI-12 and sham groups (30% +/- 10% versus 9% +/- 7%, 0% +/- 0%, P < 0.05). Immunohistochemical analysis revealed increased amyloid precursor protein immunoreactivity in the swollen axons, especially in the SCI-15 group. There was a significant negative correlation between the number of normal neurons and percentages of vacuolation areas. These results indicate that both gray and white matter were injured after SCI in rats and the degree of white mater injury was correlated with the severity of gray matter injury after a relatively short recovery period.

Amyloid beta-Protein Precursor↗
PubMed2001

Comparison of spinal cord gray matter and white matter softness: measurement by pipette aspiration method.

OBJECT: Although the gray matter of the spinal cord has been thought to be softer than the white matter, there is no evidence to support this belief. Because the spinal cord is extremely soft, it has been difficult to measure the mechanical properties of the gray and white matter. The modulis of elasticity of the gray and white matter were measured in situ by using a pipette aspiration method. METHOD: The spinal cord specimens were excised from Japanese white rabbits. Specimens were cut to display the surfaces of axial, frontal, and sagittal sections. The surfaces of the gray and white matter were aspirated using a 0.8-mm-inner-diameter glass pipette while monitoring with a video microscope, and the deformed length in the pipette was measured on a monitor. In each case the modulus of elasticity was calculated by comparing the relationship between the aspiration pressure and aspirated volume of the specimen with that determined by finite element analysis. The moduli of elasticity of the gray and white matter were 3.4+/-1.4 kPa (mean +/- standard deviation) and 3.4+/-0.9 kPa in the axial section, 3+/-0.3 kPa and 3.5+/-0.5 kPa in the frontal section, and 3.5+/-0.9 kPa and 2.8+/-0.4 kPa in the sagittal section, respectively. CONCLUSIONS: No significant difference in modulus of elasticity was shown between the gray and white matter of the spinal in sections made in various directions.

Animals↗
PubMed1989

Rat CNS white matter, but not gray matter, is nonpermissive for neuronal cell adhesion and fiber outgrowth.

In adult mammalian CNS, axons mostly fail to regenerate after injury, while in the PNS they often succeed in reaching their previous targets. Crucial differences are present in the local tissue microenvironment of CNS and PNS. To investigate the substrate properties of nervous tissue for neuronal adhesion and fiber growth, we used frozen sections of rat CNS and PNS as culture substrates for neuroblastoma cells and for sympathetic and dorsal root ganglia. The results showed that CNS white matter from adult rat spinal cord, cerebellum, forebrain, or optic nerve did not allow cell adhesion and axonal elongation. In contrast, gray matter areas, sciatic nerve, and also trout CNS white and gray matter were permissive substrates. To delineate the tissue components of white matter involved in this nonpermissive substrate effect, newborn rats were injected for 13 d with the antimitotic agent 5-azacytidine. This treatment strongly reduced the oligodendrocyte population and the myelin content of the spinal cord. The immunoreactivity for specific oligodendrocyte and astrocyte markers confirmed the selective suppression of oligodendroglia in these rats. Neuroblastoma cells plated on spinal cord sections taken from these animals were no longer exclusively localized on the gray matter but were also found on regions normally rich in myelin. A significant reduction of the white matter nonpermissive substrate effect was also obtained by the monoclonal antibody IN-1 directed against 2 defined myelin proteins with inhibitory substrate properties (Caroni and Schwab, 1988b). Our results, therefore, show that, in the adult mammalian CNS, cell adhesion and axonal elongation are prevented by white matter components, which are, at least in part, associated with oligodendrocytes and myelin.

Animals↗
PubMed1985

Phosphoethanolamine and phosphocholine transferases in gray matter and white matter from developing rat brain.

We have studied the activities of 2',3'-cyclic nucleotide 3'-phosphohydrolase, 1,2-diacylglycerol: CDPethanolamine phosphoethanolamine transferase (EC 2.7.8.1), and 1,2-diacylglycerol: CDPcholine phosphocholine transferase (EC 2.7.8.2) in developing rat brain gray matter and white matter. The specific activity of cyclic nucleotide phosphohydrolase was 5-8 fold higher in white matter than in gray matter at all ages. No significant changes were observed during development. The specific activity of phosphocholine transferase was 2 to 3 fold higher than phosphoethanolamine transferase at all ages both in gray and white matter. Both phosphocholine transferase and phosphoethanolamine transferase increased more than 2 fold in specific activity between 14 and 90 days of age. The total activity of phosphocholine transferase also showed an increase during development. The apparent Km values for nucleotides and dicaprin were similar in gray matter and white matter. Except for low Km values for nucleotides at 14 days of age, no significant changes were observed during development. Changes in rates of glycerophospholipid synthesis may be partly due to the specific activities of these enzymes but are also determined by the quantities of substrates and inhibitors and by affinities for the substrates.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗
PubMed1994

MR volume segmentation of gray matter and white matter using manual thresholding: dependence on image brightness.

PURPOSE: To describe a quantitative MR imaging segmentation method for determination of the volume of cerebrospinal fluid, gray matter, and white matter in living human brain, and to determine the method's reliability. METHODS: We developed a computer method that allows rapid, user-friendly determination of cerebrospinal fluid, gray matter, and white matter volumes in a reliable manner, both globally and regionally. This method was applied to a large control population (N = 57). RESULTS: Initially, image brightness had a strong correlation with the gray-white ratio (r = .78). Bright images tended to overestimate, dim images to underestimate gray matter volumes. This artifact was corrected for by offsetting each image to an approximately equal brightness. After brightness correction, gray-white ratio was correlated with age (r = -.35). The age-dependent gray-white ratio was similar to that for the same age range in a prior neuropathology report. Interrater reliability was high (.93 intraclass correlation coefficient). CONCLUSIONS: The method described here for gray matter, white matter, and cerebrospinal fluid volume calculation is reliable and valid. A correction method for an artifact related to image brightness was developed.

Adult↗
PubMed2005

Gray matter reduction is correlated with white matter hyperintensity volume: a voxel-based morphometric study in a large epidemiological sample.

Both brain atrophy and T2-weighted white matter hyperintensities (WMH) are common findings in the brains of asymptomatic elderly individuals as well as in disease-specific brains. The study of the relationship between these two salient features is therefore important. To investigate such a relationship, we performed a brain magnetic resonance imaging (MRI) study on 397 asymptomatic individuals aged between 60 and 64 years, who were recruited randomly from a large community sample. WMH were delineated on T2-weighted fluid attenuation inversion recovery (FLAIR) whole brain scans using an automated procedure. The results showed that gray matter reduction, subarachnoid CSF (SA-CSF) increase and lateral ventricular dilation were significantly correlated with WMH load. Deep white matter hyperintensity (DWMH) had significant correlation with all three global atrophy indices, but periventricular white matter hyperintensity (PVWMH) was correlated only with gray matter volume. Voxel-based morphometric (VBM) analysis showed that regional gray matter reduction correlated more closely with WMH load of the proximate region than with WMH elsewhere. The results suggest that WMH have a relationship with brain atrophy in middle age, although the study cannot determine which process, i.e. the development of WMH or atrophy, is primary. The study also demonstrates that DWMH has a more significant relationship with structural brain changes, and may therefore be more functionally relevant than PVWMH. Further delineation of this relationship needs a longitudinal study of the changes in both WMH and indices of brain atrophy.

Age Factors↗
PubMed2003

Magnetization transfer and T2 quantitation in normal appearing cortical gray matter and white matter adjacent to focal abnormality in patients with traumatic brain injury.

Traumatic brain injury (TBI) is one of the commonest causes of morbidity and mortality in the developed countries with posttraumatic epilepsy and functional disability being its major sequelae. The purpose of this study was to test the hypothesis whether the normal appearing adjacent gray and white matter regions on T2 and T1 weighted magnetization transfer (MT) weighted images show any abnormality on quantitative imaging in patients with TBI. A total of 51 patients with TBI and 10 normal subjects were included in this study. There were significant differences in T2 and MT ratio values of T2 weighted and T1 weighted MT normal appearing gray matter regions adjacent to focal image abnormality compared to normal gray matter regions in the normal individuals as corresponding contralateral regions of the TBI patient's group (p < 0.05). However the adjoining normal appearing white matter quantitative values did not show any significant change compared to the corresponding contralateral normal white matter values. We conclude that quantitative T2 and MT ratio values provide additional abnormality in patients with TBI that is not discernable on conventional T2 weighted and T1 weighted MT imaging especially in gray matter. This additional information may be of value in overall management of these patients with TBI.

Adolescent↗
PubMed1998

Gray matter and white matter perfusion imaging in patients with severe carotid artery lesions.

PURPOSE: To determine, with dynamic susceptibility contrast-enhanced magnetic resonance (MR) imaging, changes in gray matter and white matter perfusion in patients with internal carotid artery (ICA) occlusions. MATERIALS AND METHODS: Regional cerebral blood volume (CBV), mean transit time, arrival time (time for contrast material to arrive in the brain), and peak time (time to highest contrast material concentration in the brain) were determined in 44 patients and 33 control subjects. Patients were divided into three groups: patients with a unilateral ICA occlusion, patients with a unilateral ICA occlusion and a contralateral severe stenosis (> 70%), and patients with bilateral ICA occlusions. RESULTS: Compared with control subjects, patients with unilateral ICA occlusions had hemodynamic changes in the ipsilateral hemisphere: Mean transit time, arrival time, and peak time were increased in white and gray matter (P < .001), and regional CBV was significantly increased in white matter only (P < .01). Hemodynamic changes were more pronounced in patients with bilateral ICA occlusions: Compared with control subjects, mean transit time, arrival time, peak time, and regional CBV were increased in both white and gray matter in both hemispheres (P < .001). CONCLUSION: Dynamic susceptibility contrast-enhanced MR imaging can enable measurement of relative hemodynamic changes in patients with ICA occlusions, with the advantage that gray and white matter perfusion can be distinguished.

Adult↗
PubMed2001

Mathematical segmentation of grey matter, white matter and cerebral spinal fluid from MR image pairs.

The aims of this study were (1) to design a mathematical segmentation technique to allow extraction of grey matter, white matter and cerebral spinal fluid volumes from paired high resolution MR images and (2) to document the statistical accuracy of the method with different image combinations. A series of linear equations were derived that describe proportional tissue volumes in individual image voxels. The equations use estimates of pure tissue values to derive the proportion of each tissue within a single voxel. Repeatability of manual estimations of pure tissue values was assessed both using regions of interest and thresholding techniques. Statistical accuracy of tissue estimations for a variety of image pairs was assessed from measurements of root-mean-square noise and mean grey level intensity. The technique was used to produce parametric images of grey and white matter distribution. The segmentation technique showed greatest statistical accuracy when the first image has high grey/white matter contrast and the second image has little contrast or the rank order of the signal intensities from pure tissue is reversed. A combination of inversion recovery fast spin echo and fast FLAIR images produced a statistical error of 11% for grey matter and 10% for white matter for any given voxel. The effect of increasing sample size improves both of these figures to give a 1% statistical error on a 100 pixel sample.

Algorithms↗
PubMed2001

Do I matter? Construct validation of adolescents' perceived mattering to parents and friends.

Although the perception of mattering to others has been described as important for psychosocial well-being (Coopersmith, 1967; Rosenberg, 1985), very little attention has been given to the empirical study, measurement, and evaluation of this construct. The present project employed Loevinger's (1957) three-component model for construct validation to examine the construct validity of perceived mattering to mothers, fathers, and friends. Findings provide support for theoretical inferences about the characteristics of perceived mattering. For example, purpose for life and a sense of relatedness are positively associated with perceived mattering and perceived mattering appears to be a distinct construct from global self-esteem

Adolescent↗