Hurlemann René, Arndt Stephan, Schlaepfer Thomas E, Reul Juergen, Maier Wolfgang, Scheele Dirk
1] Department of Psychiatry, University of Bonn, 53105 Bonn, Germany [2] Division of Medical Psychology, University of Bonn, 53105 Bonn, Germany.
1] Department of Psychiatry, University of Bonn, 53105 Bonn, Germany [2] Department of Psychiatry &Behavioral Medicine, The Johns Hopkins Hospital, Baltimore, Maryland, 21287, USA.
Sci Rep. 2015 Mar 10;5:8954. doi: 10.1038/srep08954.
From an evolutionary perspective the startle eye-blink response forms an integral part of the human avoidance behavioral repertoire and is typically diminished by pleasant emotional states. In major depressive disorder (MDD) appetitive motivation is impaired, evident in a reduced interference of positive emotion with the startle response. Given the pivotal role of frontostriatal neurocircuitry in orchestrating appetitive motivation, we hypothesized that inhibitory transcranial magnetic stimulation (TMS) would reduce appetitive neuromodulation in a manner similar to MDD. Based on a pre-TMS functional MRI (fMRI) experiment we selected the left dorsolateral and dorsomedial prefrontal cortices as target regions for subsequent sham-controlled inhibitory theta-burst TMS (TBS) in 40 healthy male volunteers. Consistent with our hypothesis, between-group comparisons revealed a TBS-induced inhibition of appetitive neuromodulation, manifest in a diminished startle response suppression by hedonic stimuli. Collectively, our results suggest that functional integrity of left dorsolateral and dorsomedial prefrontal cortex is critical for mediating a pleasure-induced down-regulation of avoidance responses which may protect the brain from a depressogenic preponderance of defensive stress.
从进化的角度来看，惊吓眨眼反应是人类回避行为的一个组成部分，通常会因愉悦的情绪状态而减弱。在重度抑郁症（MDD）中，奖赏动机受损，表现为积极情绪对惊吓反应的干扰减少。鉴于前额叶纹状体神经回路在协调奖赏动机中起关键作用，我们假设抑制性经颅磁刺激（TMS）会以类似于MDD的方式减少奖赏性神经调节。基于TMS前的功能磁共振成像（fMRI）实验，我们选择了40名健康男性志愿者的左侧背外侧和背内侧前额叶皮质作为目标区域，随后进行假对照抑制性theta爆发TMS（TBS）。与我们的假设一致，组间比较显示TBS诱导了对奖赏性神经调节的抑制，表现为享乐刺激引起的惊吓反应抑制减弱。总体而言，我们的结果表明，左侧背外侧和背内侧前额叶皮质的功能完整性对于介导愉悦诱导的回避反应下调至关重要，这可能保护大脑免受防御性应激导致抑郁的优势影响。
