Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at University of California, Los Angeles, California, USA.
Biol Psychiatry. 2013 Jan 15;73(2):127-35. doi: 10.1016/j.biopsych.2012.06.030. Epub 2012 Aug 1.
The symptoms of bipolar disorder suggest dysfunction of emotion regulatory networks. In healthy control populations, downregulation of emotional responses activates the ventral lateral prefrontal cortex (vlPFC) and dampens amygdala activation. This study investigated frontal and limbic function and connectivity during emotion downregulation in euthymic subjects with bipolar I disorder (BPI) and healthy control subjects.
Thirty BPI and 26 control subjects underwent functional magnetic resonance imaging scanning while performing an emotion processing task with passive viewing and emotion downregulation conditions. Contrasts were made for each group comparing the downregulation and passive viewing conditions, and these were entered into a between-group random effects analysis to assess group differences in activation. Psychophysiological interaction analyses were conducted to test for significant group differences in functional connectivity between the amygdala and inhibitory frontal regions (i.e., vlPFC).
Control subjects showed the expected robust bilateral activation of frontal and limbic regions during passive viewing and emotion downregulation tasks. Between-group analyses revealed similar activation of BPI and control subjects during passive viewing but significantly decreased activation in bilateral vlPFC, bilateral anterior and posterior cingulate, medial frontal gyrus, and bilateral dorsal lateral prefrontal cortex during emotion downregulation in subjects with BPI. Connectivity analysis demonstrated that control subjects had significantly greater negative functional connectivity between the left amygdala and bilateral vlPFC compared with subjects with BPI.
This study provides evidence that dysfunction in the neural networks responsible for emotion regulation, including the prefrontal cortex, cingulate, and subcortical structures, are present in BPI subjects, even while euthymic.
双相情感障碍的症状表明情绪调节网络功能障碍。在健康对照组中，情绪反应的下调会激活腹外侧前额叶皮层（vlPFC）并抑制杏仁核的激活。本研究调查了双相情感障碍 I 型（BPI）和健康对照组的静息期患者在情绪下调期间的额叶和边缘功能和连接。
30 名 BPI 和 26 名对照组受试者在执行情绪处理任务时进行功能磁共振成像扫描，具有被动观察和情绪下调条件。对每组进行对比，比较下调和被动观察条件，并将这些对比输入组间随机效应分析，以评估组间在激活方面的差异。进行心理生理相互作用分析，以测试杏仁核和抑制性额叶区域（即 vlPFC）之间的功能连接是否存在显著的组间差异。
对照组在被动观察和情绪下调任务中表现出预期的额叶和边缘区域的强烈双侧激活。组间分析显示，BPI 和对照组在被动观察时的激活相似，但在 BPI 患者的情绪下调期间，双侧 vlPFC、双侧前扣带回和后扣带回、内侧额叶和双侧背外侧前额叶皮层的激活明显降低。连接分析表明，与 BPI 患者相比，对照组在左侧杏仁核和双侧 vlPFC 之间具有显著更强的负性功能连接。
这项研究提供了证据表明，即使在静息期，负责情绪调节的神经网络功能障碍，包括前额叶皮层、扣带回和皮质下结构，在 BPI 患者中存在。
