Back to Search
Start Over
Influence of motor activity on striatal dopamine release: A study using iodobenzamide and SPECT.
- Source :
-
NeuroImage [Neuroimage] 1999 Sep; Vol. 10 (3 Pt 1), pp. 261-8. - Publication Year :
- 1999
-
Abstract
- Pharmacologically induced dopamine release can influence the postsynaptic receptor binding of dopaminergic radioligands. This effect has recently been described using in vivo imaging methods and has been attributed to competition of radiotracers with the endogenous ligand. The present study examines the effect of a motor activation task on dopamine release and the consequences of this release on the binding of the selective D(2) receptor ligand (123)I-iodobenzamide (IBZM) to striatal dopamine D(2) receptors. Eight subjects were asked to write a text beginning immediately before IBZM injection and continuing for 30 min thereafter. Eighteen other subjects remained in a supine resting state during this period and served as a control group. All subjects were right handed. We hypothesized that the writing task would lead to an increase of dopamine release. The increased competition of the endogenous ligand with IBZM should lead to a decreased postsynaptic IBZM binding in the experimental group. Images were acquired and reconstructed identically and anatomically normalized to a computerized brain atlas. Regions of interest were drawn covering the striatum and three different reference regions. Ratios of striatal-to-reference-tissue radioactivity accumulation were calculated as semi-quantitative estimates of D(2) receptor binding potential. This decreased bilaterally, although right-sided significantly more than left, regardless of the choice of reference region. These data show that writing with the right hand compared to a supine resting state leads to a decrease of striatal IBZM accumulation. According to our primary hypothesis this reflects dopamine release.<br /> (Copyright 1999 Academic Press.)
- Subjects :
- Adult
Aged
Cerebellum diagnostic imaging
Female
Functional Laterality
Humans
Male
Middle Aged
Parietal Lobe diagnostic imaging
Writing
Benzamides pharmacokinetics
Brain Mapping
Cerebellum physiology
Corpus Striatum diagnostic imaging
Corpus Striatum physiology
Dopamine metabolism
Iodine Radioisotopes pharmacokinetics
Motor Activity physiology
Parietal Lobe physiology
Psychomotor Performance physiology
Pyrrolidines pharmacokinetics
Tomography, Emission-Computed, Single-Photon methods
Subjects
Details
- Language :
- English
- ISSN :
- 1053-8119
- Volume :
- 10
- Issue :
- 3 Pt 1
- Database :
- MEDLINE
- Journal :
- NeuroImage
- Publication Type :
- Academic Journal
- Accession number :
- 10458941
- Full Text :
- https://doi.org/10.1006/nimg.1999.0461