Jones Rhiannon, Craig Gavin, Bhattacharya Joydeep
Department of Psychology, University of Winchester, Winchester, United Kingdom.
Department of Psychology, University of Westminster, London, United Kingdom.
Front Psychol. 2019 Aug 21;10:1922. doi: 10.3389/fpsyg.2019.01922. eCollection 2019.
The Met allele of the brain-derived neurotrophic factor (BDNF) Val66Met polymorphism is associated with reduced functioning of the amygdala and hippocampus. It has been linked to major psychiatric conditions, including depression and post-traumatic stress disorder, and is associated with deficits in episodic memory. The precise mechanisms of the BDNF gene's influence on emotional memory are not well characterized, especially its impact on recognition. Two electrophysiological experiments of emotional memory were run on two independent samples genotyped for BDNF Val66Met. Event-related potentials (ERPs) corresponding to the recognition of negative and neutral words (Experiment 1, = 37) and negative and positive words (Experiment 2, = 23) were recorded, and the late parietal component (LPC), typically associated with conscious recollection, was analyzed. In Experiment 1, a reduced LPC was observed in Met carriers ( = 12) compared to Val homozygotes = 25) in the negative condition, but the group difference was not present in the neutral condition. In Experiment 2, the reduced LPC was seen in Met carriers ( = 12) compared to Val homozygotes ( = 11) across both conditions. This study provides the first evidence of an association between the BDNF Val66Met genotype and the late parietal electrophysiological component, suggesting that the conscious experience of emotional recollection may differ according to BDNF Val66Met genotype. Further, these results suggest that this effect is likely due to emotional arousal rather than valence polarity. Results were discussed with reference to the possible mechanisms by which emotional recollection deficits may contribute to psychopathology.
脑源性神经营养因子（BDNF）Val66Met多态性的Met等位基因与杏仁核和海马体功能减退有关。它与包括抑郁症和创伤后应激障碍在内的主要精神疾病有关，并且与情景记忆缺陷有关。BDNF基因对情绪记忆影响的确切机制尚未得到充分表征，尤其是其对识别的影响。在两个独立的样本上进行了两项关于情绪记忆的电生理实验，这些样本针对BDNF Val66Met进行了基因分型。记录了与识别消极和中性词（实验1，n = 37）以及消极和积极词（实验2，n = 23）相对应的事件相关电位（ERP），并分析了通常与有意识回忆相关的顶叶晚期成分（LPC）。在实验1中，在消极条件下，与Val纯合子（n = 25）相比，Met携带者（n = 12）的LPC降低，但在中性条件下不存在组间差异。在实验2中，在两种条件下，与Val纯合子（n = 11）相比，Met携带者（n = 12）的LPC均降低。本研究首次提供了BDNF Val66Met基因型与顶叶晚期电生理成分之间存在关联的证据，表明情绪回忆的有意识体验可能因BDNF Val66Met基因型而异。此外，这些结果表明这种效应可能是由于情绪唤醒而非效价极性。讨论了情绪回忆缺陷可能导致精神病理学的可能机制。
