title: Preserved serotonin transporter binding in de novo Parkinson's disease: negative correlation with the dopamine transporter.
abstract: Recent imaging and neuropathological studies indicate reduced serotonin transporter (SERT) in advanced Parkinson's disease (PD). However, data on SERT in early PD patients are sparse. Following the hypothesis that the serotonergic system is damaged early in PD, the aim of our study was to investigate SERT availability by means of PET imaging. Since the loss of dopaminergic neurons is the pathologic hallmark of PD and SERT might be associated with psychiatric co-morbidity, we further sought to correlate SERT availability with the availability of dopamine transporter (DAT) and depressive or motor symptoms in early PD. We prospectively recruited nine early PD patients (4 female, 5 male; 42-76 years) and nine age matched healthy volunteers (5 female, 4 male; 42-72 years). Diagnosis of PD was confirmed by the UK brain bank criteria and DAT imaging. SERT availability was measured by means of [11C]DASB PET. For neuropsychiatric assessment done on the day of PET we applied UPDRS parts I, II and III, Beck's Depression Inventory, Hamilton Rating Scale for Depression, Mini-Mental State Examination and Demtect. SERT was not reduced in any of 14 investigated regions of interest in the nine PD patients compared to healthy controls (p>0.13). SERT was negatively associated with DAT in the striatum (r=-0.69; p=0.04) but not within the midbrain. There was no correlation of SERT availability with depressive symptoms. No alteration of SERT binding in our patients suggests that the serotonergic system is remarkably preserved in early PD. Correlation with DAT might point to a compensatory regulation of the serotonergic system in early stages of PD.
authors.affiliation: Department of Neurology, University of Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany. KarlStrecker@gmx.de
authors.forename: Karl
authors.initials: K
authors.lastname: Strecker
authors.forename: Florian
authors.initials: F
authors.lastname: Wegner
authors.forename: Swen
authors.initials: S
authors.lastname: Hesse
authors.forename: Georg-Alexander
authors.initials: GA
authors.lastname: Becker
authors.forename: Marianne
authors.initials: M
authors.lastname: Patt
authors.forename: Philipp M
authors.initials: PM
authors.lastname: Meyer
authors.forename: Donald
authors.initials: D
authors.lastname: Lobsien
authors.forename: Johannes
authors.initials: J
authors.lastname: Schwarz
authors.forename: Osama
authors.initials: O
authors.lastname: Sabri
mesh_terms: D000328:Adult; D017668:Age of Onset; D000368:Aged; D001923:Brain Chemistry; D003863:Depression / Q000209:etiology / Q000523:psychology; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000523:psychology; D049268:Positron-Emission Tomography; D011485:Protein Binding; D011569:Psychiatric Status Rating Scales; D050486:Serotonin Plasma Membrane Transport Proteins / Q000378:metabolism*
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins; D050486:Serotonin Plasma Membrane Transport Proteins