Functional MRI (fMRI) holds the promise of non-invasive mapping human brain function in both health and disease. Yet its sensitivity reliability for higher cognitive are still being determined. Using verbal fluency as a task, objective was to ascertain consistency fMRI on conventional scanner determining anatomic substrate language between subjects sexes. Comparison made with previous PET studies.Using 1.5 Tesla magnet an echoplanar pulse sequence, whole obtained from 12 normal right handed...

Local cerebral metabolic rates were determined by positron emission tomography and the deoxyglucose method in a group of 10 chronic schizophrenic subjects before after somatic treatment eight normal subjects. Before treatment, had markedly lower absolute activity than did controls both frontal temporal regions trend toward relative hyperactivity basal ganglia area. After their approached those seen nearly all except frontal. Persistence diminished metabolism was manifested as significant...

Abstract Bilatera decreases in striatal 11 C‐raclopride binding were observed adult female baboons with high resolution PET following administration of drugs that act centrally on dopaminergic neurons. At baseline and d‐amphetamine (a dopamine‐releasing drug), GBR‐12909 potent dopamine reuptake inhibitor), or tetrabenazine biogenic amine depleting drug) scans obtained a CTI 931 positron tomograph. In all studies, the ratio distribution volumes for striatum to cerebellum decreased...

Because CNS neuroleptic concentration cannot be directly measured in patients, the relation between clinical response and extent of dopamine receptor blockade is unknown. This relationship critical ascertaining whether nonresponse to neuroleptics result merely inadequate drug levels or more basic biological differences pathophysiology. Using [18F]N-methylspiroperidol positron emission tomography, authors assessed occupancy 10 schizophrenic patients before after treatment with haloperidol....

Using [11C]-deoxy-D-glucose and positron emission tomography (PET), the authors measured brain metabolism in 18 patients with chronic schizophrenia to assess which of metabolic measures from two test conditions was more closely related patients' differing clinical characteristics. The were resting activation, an eye tracking task used. Patients negative symptoms showed lower global rates severe hypofrontality than did fewer symptoms. Differences among distinguished by task: sicker failed...

Positron emission tomography and in vivo microdialysis were used to study serotonin's role modulating striatal dopamine. Serial PET studies performed adult female baboons at baseline following drug treatment, using the dopamine (D2) selective radiotracer, 11C-raclopride. The serotonergic system was manipulated by administration of 5-HT reuptake inhibitor, citalopram, or (5-HT2) receptor blockade (using altanserin, a 5-HT2 antagonist). 11C-Raclopride time-activity data from striatum...

Extensive neuroanatomical, neurophysiological, and behavioral evidence demonstrates that GABAergic neurons inhibit endogenous dopamine release in the mammalian corpus striatum. Positron emission tomography (PET) studies adult female baboons, using D2-specific radiotracer 11C-raclopride, were undertaken to assess utility of this imaging technique for measuring these dynamic interactions vivo. 11C-raclopride binding was imaged prior following administration either gamma-vinyl-GABA (GVG), a...

Cocaine's addictive liability has been linked to its pharmacologic actions on mesotelencephalic dopamine (DA) reinforcement/reward pathways in the central nervous system (CNS). Dopaminergic transmission within these is modulated by gamma-aminobutyric acid (GABA). With this knowledge, we examined utility of gamma vinylGABA (GVG), a selective and irreversible inhibitor GABA-transaminase (GABA-T) known potentiate GABAergic inhibition, alter cocaine's biochemical effects as well behaviors...

To investigate hydroxocobalamin's role in preventing cyanide intoxication from sodium nitroprusside, we studied two groups of patients. One group received nitroprusside alone, and the other hydroxocobalamin. Red-cell plasma levels were 83.44 +/- 23.12 3.51 1.01 microgram per 100 ml after alone 33.18 17.29 2.18 0.65 plus Acidosis developed patients with red-cell higher than 75 ml. When hydroxocobalamin infusion was stopped before discontinued, blood base deficit increased a manner similar to...

Like many psychostimulant drugs, nicotine elevates extracellular and synaptic dopamine (DA) concentrations in the nucleus accumbens (NAc). This elevation has been linked to its reinforcing properties. Dopaminergic transmission within NAc is modulated by gamma-aminobutyric acid (GABA). Therefore, we examined utility of gamma vinyl-GABA (GVG, Vigabatrin) for inhibiting nicotine's biochemical effects on DA as well behaviors associated with these changes. Given 2.5 hours prior nicotine, GVG (75...

Positron emission tomography with 11 C-2-deoxyglucose was used to determine the test-retest variability of regional cerebral glucose metabolism in 22 young normal right-handed men scanned twice a 24-h period under baseline (resting) conditions. To assess effects scan order and time day on variability, 12 subjects were morning afternoon same (a.m.-p.m.) 10 reverse (p.m.-a.m.) night between. The effect anxiety also assessed. Seventy-three percent total subject group showed changes whole brain...

Previously we demonstrated that positron emission tomography (PET) can be used to measure changes in the concentrations of synaptic dopamine and acetylcholine. Whether induced directly or indirectly through interactions with other neurotransmitters, these studies support use PET for investigating functional responsiveness a specific neurotransmitter pharmacologic challenge. In an extension findings human brain, designed striatal release central cholinergic blockade were conducted normal male...

Positron emission tomography (PET) with 11C-2-deoxyglucose (11DG) was used to compare regional brain metabolism in four patients chronic schizophrenia who had no history of psychotropic medication and 12 normal controls. Patients a second PET scan after an injection thiothixene evaluate the effects acute neuroleptics on glucose metabolism. The showed higher metabolic values than normals did not show hypofrontality reported medicated schizophrenia. Administration neuroleptic have significant...

This study examined the safety and efficacy of gamma vinyl-GABA (GVG, vigabatrin) for treatment methamphetamine and/or cocaine addiction. A total 30 subjects, who met DSM-IV criteria dependence, were enrolled in an open label 9-week study. The protocol was specifically designed to include extensive visual field monitoring as well outcome measures therapeutic efficacy. Patients screened twice weekly presence urinary cocaine, methamphetamine, heroin, alcohol, marijuana. In total, 18/30...

Abstract The muscarinic cholinergic system has been mapped in vivo inhuman and baboon brain using [N‐ 11 C‐methyl]‐benztropine high resolution positron emission tomography (PET). uptake was observed frontal, parietal, occipital, temporal cortices as well subcortical structures including the corpus striatum thalamus. Uptake continued to increase human all areas over an 80 minute experimental period with exception of cerebellum wehere accumulation radioactivity began decrease by 25 minutes...

Brain metabolism was measured with positron emission tomography and [ 11 C]deoxyglucose during baseline a visual task in 12 normal subjects 18 schizophrenic patients. Global measures of for brain regions were transformed into relative values by dividing them the metabolic value whole brain. Factor analysis accomplished on matrix intercorrelations among regional patients under task. Four factors that revealed independently varying frontal, occipital, left-versus-right hemisphere, subcortical...

t’ion. Direct proof that mevalonic and fatty acid syntheses are accomplished by an avian enzyme system through enzyme-bound intermediates was provided in a preliminary communication from our laboratory (3). of the formation biosynthesis preparation Escherichia coli earlier reports isolation acetoacetyl-enzyme (4) its conversion to butyryl-enzyme (5) long chain acids (4), report caproylenzyme (5). Earlier work Lynen (6) also established is formed particulate yeast partially purified for...

GABA modulates dopamine concentrations in the nucleus accumbens and corpus striatum. Using vivo microdialysis techniques we examined this modulatory role extent to which three different GABAergic drugs can attenuate cocaine's ability increase extracellular gross locomotor activity. Ethanol, lorazepam (Ativan), gamma-vinyl (GVG) significantly dose-dependently attenuated cocaine-induced release striatum of freely moving animals. Unlike ethanol or lorazepam, however, GVG is not a sedative...

The effect of endogenous dopamine on PET measures radioligand binding is important to the measurement receptor density (or availability) and neurotransmitter interactions in vivo. We recently reported that pretreatment with amphetamine, a drug which stimulates release, significantly reduced NMS baboon brain as determined by product lambda k3 derived from graphical analysis method for irreversible systems (lambda ratio forward reverse plasma tissue transport constants proportional density)...

The relationship between alterations in brain structure and function was studied vivo both young elderly human subjects. Computed tomography revealed significant age-related ventricular cortical sulcal dilatation. changes were most closely related to age. Positron emission failed show regional glucose metabolic rate. results suggest that the normal aging undergoes structural atrophic without incurring changes. Examination of correlations measures no relationships. These data are discussed...

Positron emission tomography and the fluorodeoxyglucose (FDG) method were used to determine brain's metabolic response neuroleptic challenge in a normal, disease-free state.FDG measurements obtained before 12 hours after administration of 5 mg haloperidol young normal men. These values compared with test-retest FDG measures from nine male control subjects who received no drug intervention.After administration, showed significantly lower glucose utilization neocortex, limbic cortex, thalamus,...