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Receptor Availability (receptor + availability)

Distribution by Scientific Domains

Medical Sciences	85%

Selected Abstracts

Substantial Thalamostriatal Dopaminergic Defect in Unverricht-Lundborg Disease

EPILEPSIA, Issue 9 2007
Miikka Korja
Summary:,Purpose: Unverricht-Lundborg disease (ULD) is currently classified as progressive myoclonus epilepsy. Myoclonus, the characteristic symptom in ULD, suggests that dopamine neurotransmission may be involved in the pathophysiology of ULD. Our purpose was to examine brain dopaminergic function in ULD patients. Methods: Four genetically and clinically diagnosed ULD patients and eight healthy controls were scanned with [11C]raclopride-PET. PET images were coregistered to individual 1.5T MR images and region-of-interest analysis was performed for the striatum and thalamus. Standardized uptake values and individual voxel-wise binding potential maps of the patients and controls were also analyzed. Results: ULD patients had markedly higher (31,54%) dopamine D2-like receptor availabilities than healthy controls in both the striatum and the thalamus. The proportionally highest binding potentials were detected in the thalamus. There were no significant differences in the cerebellar uptake of [11C]raclopride in ULD patients versus healthy controls. Voxel-based results were in accordance with the region-of-interest analysis. Conclusions: These results suggest that dopaminergic modulation at the level of the striatum and thalamus could be a crucial factor contributing to the symptoms of ULD. In the light of our data, we propose that ULD with dopamine dysfunction and dyskinetic symptoms shares certain pathophysiological mechanisms with classical movement disorders. Future studies are therefore warranted to study the effect of dopaminergic pharmacotherapy in ULD. [source]

Striatal dopamine D2 receptor availability in OCD with and without comorbid social anxiety disorder: preliminary findings,

DEPRESSION AND ANXIETY, Issue 1 2008
Franklin R. Schneier M.D.
Abstract Dopamine D2 receptor availability in the striatum has been reported to be low in generalized social anxiety disorder (GSAD) and obsessive,compulsive disorder (OCD), but it has not been studied in persons with comorbid OCD and GSAD (OCD+GSAD). D2 receptor availability was assessed in 7 subjects with OCD+GSAD, 8 with OCD, and 7 matched healthy comparison (HC) subjects, all unmedicated adults. D2 receptor availability was assessed with single-photon emission computerized tomography (SPECT) to measure binding potential (BP) of the D2 receptor radiotracer [123I] iodobenzamide ([123I]IBZM). Mean striatal [123I]IBZM BP was significantly lower in the OCD+GSAD group (72.58 mL/g, SD=18.17) than in the HC group (118.41 mL/g, SD=45.40; P=.025). Mean BP in the OCD group (93.08 mL/g, SD=36.90) did not differ significantly from the HC group (P=.247). Trait detachment, as measured by the Detachment subscale of the Karolinska Scales of Personality, was negatively correlated with D2 availability across all subjects (rs=,.55, P=.013). Comorbid GSAD and OCD may be associated with decreased availability of D2 receptors in the striatum, consistent with prior findings in GSAD. Prior findings of decreased D2 receptor availability in noncomorbid OCD were not confirmed. Decreased D2 receptor availability was also associated with trait detachment, supporting prior findings in samples of healthy subjects. Depression and Anxiety 0:1,7, 2007. Published 2007 Wiley-Liss, Inc. [source]

BRIEF REPORT: Varenicline increases striatal dopamine D2/3 receptor binding in rats

ADDICTION BIOLOGY, Issue 4 2009
Cleo L. Crunelle
ABSTRACT Increasing dopamine D2/3 receptor availability is postulated to be a treatment for drug addiction. Varenicline, an ,4,2-nicotinic partial agonist, is effective for nicotine dependence. We hypothesize that varenicline increases dopamine D2/3 receptor availability. Twenty male drug-naïve rats were randomized to varenicline (2 mg/kg) or placebo for 14 days, and then injected with the dopamine D2/3 radiotracer 123I-IBZM. We found significantly higher striatum-to-cerebellum binding ratios in both dorsal and ventral striatum for the varenicline group compared with placebo. Varenicline increases dopamine D2/3 receptor availability in drug-naïve rats. Therefore, varenicline may be an effective treatment for addictions other than smoking. [source]

Differential sustained changes in ,-opioid receptor availability following acupuncture and sham acupuncture therapy in fibromyalgia

FOCUS ON ALTERNATIVE AND COMPLEMENTARY THERAPIES AN EVIDENCE-BASED APPROACH, Issue 2007
RE Harris
[source]

Serotonin 5HT1A receptor availability and pathological crying after stroke

ACTA NEUROLOGICA SCANDINAVICA, Issue 2 2007
M. Møller
Objectives,,, Post-stroke depression and pathological crying (PC) implicate an imbalance of serotonergic neurotransmission. We claim that PC follows serotonin depletion that raises the binding potential (pB) of the 5-HT1A receptor antagonist [carbonyl,11C]WAY-100635, which is reversible by selective serotonin re-uptake inhibitor (SSRI) treatment. Materials and Methods,,, We PET scanned patients with acute stroke and PC and age-matched control subjects. Maps of receptor availability were generated from the images of eight cortical regions and raphe nuclei. Results,,, The maps showed highest binding in limbic areas and raphe nuclei, while binding in basal ganglia and cerebellum was negligible. Baseline binding potentials of patients were lower than that of control subjects (3.7 ± 0.6 vs 4.2 ± 0.2). Treatment with SSRI markedly reduced free receptor sites, whereas placebo administration led to a global increase. Discussion,,, The study is the first suggestion of changes of serotonergic neurotransmission in the early phase of stroke and the modulation of these changes with SSRI treatment. [source]