A1 Journal article – refereed
Rostrocaudal gradients of dopamine D-2/3 receptor binding in striatal subregions measured with [C-11]raclopride and high-resolution positron emission tomography

List of Authors: Alakurtti K, Johansson JJ, Tuokkola T, Nagren K, Rinne JO
Publication year: 2013
Journal: NeuroImage
Journal name in source: NEUROIMAGE
Journal acronym: NEUROIMAGE
Volume number: 82
ISSN: 1053-8119

The human striatum has structural and functional subdivisions, both dorsoventrally and rostrocaudally. To date, the gradients of dopamine D-2/3 receptor binding in the human striatum have not been measured with positron emission tomography (PET). Seven healthy male subjects aged 24.5 +/- 3.5 years were scanned with brain-dedicated high-resolution research tomography (HRRT, Siemens Medical Solutions, Knoxville, TN, USA) and [C-11]raclopride. Coronally defined regions of interest (ROIs) of the caudate nucleus, putamen and ventral striatum (VST) were sampled plane-by-plane, 1.5 mm apart, on spatially normalized binding potential (BPND) images. Regional [C-11]raclopride BPND values were calculated using the simplified reference tissue model (SRTM) from a total of 25 coronal planes. An increasing rostrocaudal gradient of the D-2/3 receptor binding was detected in the putamen, which is consistent with the known distribution of D-2/3 dopamine receptors. In the caudate nucleus, there was an initial increase in the BPND values in the most anterior planes, suggesting that the highest D-2/3 receptor binding occurred in the head; however, there was an overall descending gradient. A declining trend was also observed in the VST. The novelty of this study lies in the presentation, for the first time, of the D-2/3 receptor binding gradients in each striatal subregion in the brains of living healthy humans. The high spatial resolution provided by HRRT enables frequent sampling of BPND along the longitudinal extent of striatum; this method is superior to the sectioning used in previous post mortem studies. Regarding the functional organization of the striatum, our findings can inform future investigations of normal neurophysiology as well as efforts to differentiate neuropsychiatric disorders affecting the brain dopamine (DA) system. Furthermore, the average distribution of D-2/3 receptor binding revealed in this study could serve as a basis for a database that includes distributions of various DA markers as a function of healthy aging. (C) 2013 Elsevier Inc. All rights reserved.

Last updated on 2019-21-08 at 21:46