title: Striatal dopamine release after prefrontal repetitive transcranial magnetic stimulation in major depression: preliminary results of a dynamic [123I] IBZM SPECT study.
abstract: Though there is considerable evidence that prefrontal repetitive transcranial magnetic stimulation (rTMS) exerts antidepressant effects, the neurobiological action of rTMS in patients with depression is poorly understood. Preclinical studies in animals and humans have demonstrated that prefrontal rTMS can induce dopamine release in mesostriatal and mesolimbic regions. We therefore investigated whether rTMS also modulates striatal dopaminergic neurotransmission in depressed patients using a dynamic [123I] iodobenzamide (IBZM) single photon emission computed tomography (SPECT) approach. Five patients with a major depressive episode (DSM-IV) underwent an acute 10 Hz rTMS challenge with 3000 stimuli over the left dorsolateral prefrontal cortex during an [123I] IBZM-SPECT bolus and constant infusion protocol. In four subjects the protocol was repeated after a three week rTMS standard treatment. Striatal IBZM binding to dopamine D2 receptors was assessed with a region-of-interest (ROI) technique. The change in striatal IBZM binding after the rTMS challenge was regarded as measure of change in endogenous striatal dopamine. Data of nine SPECT investigations showed a significant reduction by 9.6+/-6.2% in IBZM binding to striatal dopamine D2 receptors after rTMS challenge compared to baseline (p=0.01, Wilcoxon test). In this preliminary study, the reduction of IBZM binding observed after rTMS challenge is suggestive of a release in endogenous dopamine induced by prefrontal rTMS. In future, this approach can be used to differentiate specific and non-specific reward-related effects of rTMS on dopaminergic neurotransmission.
authors.affiliation: Department of Psychiatry, Ludwig-Maximilians-University, Nussbaumstr. 7, D-80336 Munich, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Pogarell
authors.forename: Walter
authors.initials: W
authors.lastname: Koch
authors.forename: Gabriele
authors.initials: G
authors.lastname: Pöpperl
authors.forename: Klaus
authors.initials: K
authors.lastname: Tatsch
authors.forename: Franziska
authors.initials: F
authors.lastname: Jakob
authors.forename: Peter
authors.initials: P
authors.lastname: Zwanzger
authors.forename: Christoph
authors.initials: C
authors.lastname: Mulert
authors.forename: Rainer
authors.initials: R
authors.lastname: Rupprecht
authors.forename: Hans-Jürgen
authors.initials: HJ
authors.lastname: Möller
authors.forename: Ulrich
authors.initials: U
authors.lastname: Hegerl
authors.forename: Frank
authors.initials: F
authors.lastname: Padberg
mesh_terms: D000368:Aged; D001549:Benzamides; D003287:Contrast Media; D003865:Major Depressive Disorder / Q000628:therapy*; D004298:Dopamine / Q000378:metabolism*; D018492:Dopamine Antagonists; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D017397:Prefrontal Cortex / Q000378:metabolism*; D011759:Pyrrolidines; D019275:Radiopharmaceuticals; D017448:Receptors, Dopamine D2 / Q000378:metabolism; D015899:Tomography, Emission-Computed, Single-Photon; D050781:Transcranial Magnetic Stimulation / Q000379:methods
chemical_list: D001549:Benzamides; D003287:Contrast Media; D018492:Dopamine Antagonists; D011759:Pyrrolidines; D019275:Radiopharmaceuticals; D017448:Receptors, Dopamine D2; C055743:3-iodo-2-hydroxy-6-methoxy-N-((1-ethyl-2-pyrrolidinyl)methyl)benzamide; D004298:Dopamine