Shaikh Usman Jawed, Pellicano Antonello, Schüppen Andre, Heinzel Alexander, Winz Oliver H, Herzog Hans, Mottaghy Felix M, Binkofski Ferdinand
Section Clinical Cognitive Sciences, Department of Neurology, Faculty of Medicine, RWTH Aachen University, Aachen, Germany.
Department of Educational Sciences, University of Catania, Catania, Italy.
Front Neurosci. 2024 Jan 18;17:1295151. doi: 10.3389/fnins.2023.1295151. eCollection 2023.
Transcranial Magnetic Stimulation (TMS) can modulate fronto-striatal connectivity in the human brain. Here Positron Emission Tomography (PET) and neuro-navigated TMS were combined to investigate the dynamics of the fronto-striatal connectivity in the human brain. Employing 18F-DesmethoxyFallypride (DMFP) - a Dopamine receptor-antagonist - the release of endogenous dopamine in the striatum in response to time-spaced repeated bouts of excitatory, intermittent theta burst stimulation (iTBS) of the Left-Dorsolateral Prefrontal Cortex (L-DLPFC) was measured.
23 healthy participants underwent two PET sessions, each one with four blocks of iTBS separated by 30 minutes: sham (control) and verum (90% of individual resting motor threshold). Receptor Binding Ratios were collected for sham and verum sessions across 37 time frames (about 130 minutes) in striatal sub-regions (Caudate nucleus and Putamen).
Verum iTBS increased the dopamine release in striatal sub-regions, relative to sham iTBS. Dopamine levels in the verum session increased progressively across the time frames until frame number 28 (approximately 85 minutes after the start of the session and after three iTBS bouts) and then essentially remained unchanged until the end of the session.
Results suggest that the short-timed iTBS protocol performed in time-spaced blocks can effectively induce a dynamic dose dependent increase in dopaminergic fronto-striatal connectivity. This scheme could provide an alternative to unpleasant and distressing, long stimulation protocols in experimental and therapeutic settings. Specifically, it was demonstrated that three repeated bouts of iTBS, spaced by short intervals, achieve larger effects than one single stimulation. This finding has implications for the planning of therapeutic interventions, for example, treatment of major depression.
经颅磁刺激（TMS）可调节人脑的额-纹状体连接。本文将正电子发射断层扫描（PET）与神经导航TMS相结合，以研究人脑额-纹状体连接的动态变化。使用18F-去甲氧基法螺环哌啶（DMFP）——一种多巴胺受体拮抗剂——测量左背外侧前额叶皮质（L-DLPFC）在时间间隔重复进行兴奋性间歇性θ波爆发刺激（iTBS）时纹状体内内源性多巴胺的释放。
23名健康参与者接受了两次PET检查，每次检查包括四个iTBS块，间隔30分钟：假刺激（对照）和真刺激（个体静息运动阈值的90%）。在37个时间点（约130分钟）收集纹状体亚区域（尾状核和壳核）假刺激和真刺激检查的受体结合率。
与假刺激iTBS相比，真刺激iTBS增加了纹状体亚区域的多巴胺释放。真刺激检查中的多巴胺水平在各个时间点逐渐升高，直到第28帧（大约在检查开始后85分钟且经过三次iTBS刺激后），然后在检查结束前基本保持不变。
结果表明，以时间间隔块形式进行的短时间iTBS方案可有效诱导多巴胺能额-纹状体连接的动态剂量依赖性增加。该方案可替代实验和治疗环境中令人不适和痛苦的长时间刺激方案。具体而言，已证明短间隔重复三次iTBS刺激比单次刺激效果更大。这一发现对治疗干预的规划具有启示意义，例如对重度抑郁症的治疗。
