Serotonin and dopamine transporter availabilities correlate with the loudness dependence of auditory evoked potentials in patients with obsessive-compulsive disorder.
Brain monoaminergic function is involved in the pathophysiology of psychiatric disorders. The loudness dependence (LD) of the N1/P2 component of auditory evoked potentials has been proposed as a noninvasive indicator of central serotonergic function, whereas single photon emission computed tomography (SPECT) and [123I]beta-CIT can be used to visualize both serotonin (SERT) and dopamine transporters (DAT). The aim of the study was to correlate LD and SPECT measures in patients with obsessive-compulsive disorder, a condition with evidence for a serotonergic dysfunction. A total of 10 subjects received both neurophysiological and imaging investigations. Evoked potentials were recorded following the application of acoustic stimuli with increasing intensities. The LD of the relevant subcomponents (tangential dipoles) was investigated using dipole source analysis. SPECT was performed 20-24 h after injection of a mean 140 MBq [123I]beta-CIT. As a measure of brain SERT and DAT availabilities, a ratio of specific to nonspecific [123I]beta-CIT binding for the midbrain . pons region (SERT) and the striatum (DAT) was used. The LD of the right tangential dipole correlated significantly with both SERT and DAT availabilities (Pearson's correlations: rho = 0.69, p < 0.05, and rho = 0.80, p < 0.01, respectively). The correlations remained significant after controlling for the effects of age, gender, and severity of clinical symptoms. Associations between LD and both SERT and DAT availabilities further validate the use of neurophysiological approaches as noninvasive indirect measures of neurochemical brain function and point at a hypothesized interconnection of central monoaminergic systems.
Department of Psychiatry, Ludwig-Maximilians-University, Munich, Germany. oliver.pogarell@med.uni-muenchen.de
Oliver
O
Pogarell
Klaus
K
Tatsch
Georg
G
Juckel
Christine
C
Hamann
Christoph
C
Mulert
Gabriele
G
Pöpperl
Malte
M
Folkerts
Martina
M
Choukèr
Michael
M
Riedel
Michael
M
Zaudig
Hans-Jürgen
HJ
Möller
Ulrich
U
Hegerl
D000161:Acoustic Stimulation; D000328:Adult; D050483:Dopamine Plasma Membrane Transport Proteins; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000378:metabolism*; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009483:Neuropsychological Tests; D009771:Obsessive-Compulsive Disorder / Q000000981:diagnostic imaging* / Q000378:metabolism*; D050486:Serotonin Plasma Membrane Transport Proteins; D015899:Tomography, Emission-Computed, Single-Photon; D014326:Tropanes
D050483:Dopamine Plasma Membrane Transport Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; C493214:SLC6A3 protein, human; C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins; D014326:Tropanes; C087552:2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane