Vagus nerve stimulation for treatment-resistant depression: Behavioral and neural effects on encoding negative material
Vagus nerve stimulation for treatment-resistant depression: Behavioral and neural effects on encoding negative material
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DOI：
10.1097/psy.0b013e31802e106d
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发表时间：
2007-01-01
影响因子：
3.3
通讯作者：
Dolan, Raymond J.
中科院分区：
文献类型：
--
作者：
Critchley, Hugo D.;Lewis, Penelope A.;Dolan, Raymond J.
目的：迷走神经刺激（VNS）可以改善抑郁症。抑郁症的认知模型强调了负面思想和记忆的过度表现，抑郁症患者对负面材料表现出记忆促进作用。我们假设VNS的抗抑郁作用可能是通过纠正记忆中的“负性偏差”而产生的。因此，我们研究了VNS对情绪记忆及其潜在大脑活动的影响。方法：我们测试了一个单一的病人接受VNS治疗难治性抑郁症（TRID）。刺激设置在30/66秒的开/关周期，在三个编码块，当患者看到随机呈现的积极，消极和中性的话。在每个块之后，VNS被关闭，并且患者在随后的识别记忆任务中从干扰物中识别先前看到的单词。在第一个编码块期间，使用功能性磁共振成像（fMRI）对患者进行扫描。结果如下：在VNS的“关闭”周期中，对负面材料的回忆很强，但随后对负面词语的记忆在活动VNS（“打开”周期）中减弱。VNS不影响中性词和积极词的记忆。通过神经影像学，在前额叶皮层的背内侧、背外侧和眶区观察到VNS的直接调节作用。此外，在编码消极的话，与积极和中性词相比，VNS还调制活动的眶额，腹内侧和极前额叶皮质，中扣带回皮质，脑干。结论：我们的观察结果表明，迷走神经刺激可以干扰记忆的负面信息，这种影响可能有助于其抗抑郁作用。神经影像学涉及的区域包括腹侧和内侧前额叶皮层作为潜在的神经基质。
Objectives: Vagus nerve stimulation (VNS) can improve depression. Cognitive models of depression highlight an over-representation of negative thoughts and memories, with depressed individuals showing memory facilitation for negative material. We hypothesized that the antidepressant action of VNS may emerge through corrective influences on 'negativity bias' in memory. We therefore examined the impact of VNS on emotional memory and its underlying brain activity. Methods: We tested a single patient undergoing VNS for treatment-resistant depression (TRID). Stimulation was set at a 30/66-second on/off cycle during three encoding blocks when the patient viewed randomly presented positive, negative, and neutral words. Following each block, VNS was switched off and the patient identified previously seen words from distractors in a subsequent recognition memory task. The patient was scanned using functional magnetic resonance imaging (fMRI) during the first encoding block. Results: There was robust recall of negative material viewed during 'off cycles of VNS but subsequent memory of negative words was attenuated during active VNS ('on' cycles). VNS did not influence memory for neutral and positive words. With neuroimaging, direct modulatory effects of VNS were observed in dorsomedial, dorsolateral, and orbital regions of the prefrontal cortex. Moreover, during encoding of negative words, compared with positive and neutral words, VNS also modulated activity within orbitofrontal, ventromedial and polar prefrontal cortices, midcingulate cortex, and brain stem. Conclusions: Our observations show that VNS can interfere with memory of negative information, an effect that may contribute to its antidepressant role. Neuroimaging implicated regions including the ventral and medial prefrontal cortex as an underlying neural substrate.