Psychology Department University of New Hampshire Durham NH USA.
Department of Psychology and Program in Neuroscience Bowdoin College Brunswick ME USA.
Brain Behav. 2017 Nov 10;7(12):e00870. doi: 10.1002/brb3.870. eCollection 2017 Dec.
Although previous research suggests that genetic variation in dopaminergic genes may affect recognition memory, the role dopamine transporter expression may have on the behavioral and EEG correlates of recognition memory has not been well established.
The study aims to reveal how individual differences in dopaminergic functioning due to genetic variations in the dopamine transporter gene influences behavioral and EEG correlates of recognition memory.
Fifty-eight participants performed an item recognition task. Participants were asked to retrieve 200 previously presented words while brain activity was recorded with EEG. Regions of interest were established in scalp locations associated with recognition memory. Mean ERP amplitudes and event-related spectral perturbations when correctly remembering old items (hits) and recognizing new items (correct rejections) were compared as a function of dopamine transporter group.
Participants in the dopamine transporter group that codes for increased dopamine transporter expression (10/10 homozygotes) display slower reaction times compared to participants in the dopamine transporter group associated with the expression of fewer dopamine transporters (9R-carriers). 10/10 homozygotes further displayed differences in ERP and oscillatory activity compared to 9R-carriers. 10/10 homozygotes fail to display the left parietal old/new effect, an ERP signature of recognition memory associated with the amount of information retrieved. 10/10 homozygotes also displayed greater decreases of alpha and beta oscillatory activity during item memory retrieval compared to 9R-carriers.
Compared to 9R-carriers, 10/10 homozygotes display slower hit and correct rejection reaction times, an absence of the left parietal old/new effect, and greater decreases in alpha and beta oscillatory activity during recognition memory. These results suggest that dopamine transporter polymorphisms influence recognition memory.
尽管先前的研究表明，多巴胺能基因的遗传变异可能影响识别记忆，但多巴胺转运体表达对识别记忆的行为和 EEG 相关性的作用尚未得到充分证实。
本研究旨在揭示由于多巴胺转运体基因的遗传变异导致的多巴胺能功能的个体差异如何影响识别记忆的行为和 EEG 相关性。
58 名参与者进行了项目识别任务。要求参与者在大脑活动通过 EEG 记录的同时检索 200 个先前呈现的单词。在与识别记忆相关的头皮位置确定了感兴趣的区域。当正确地记住旧项目（命中）和识别新的项目（正确拒绝）时，比较了作为多巴胺转运体组函数的平均 ERP 幅度和事件相关的光谱扰动。
与表达较少多巴胺转运体的多巴胺转运体组（9R-携带者）相比，编码增加的多巴胺转运体表达的多巴胺转运体组（10/10 纯合子）的参与者反应时间较慢。与 9R-携带者相比，10/10 纯合子进一步显示出 ERP 和振荡活动的差异。10/10 纯合子未能显示出左顶叶新旧效应，这是与检索信息量相关的识别记忆的 ERP 特征。10/10 纯合子在项目记忆检索期间还显示出比 9R-携带者更大的 alpha 和 beta 振荡活动的减少。
与 9R-携带者相比，10/10 纯合子显示出较慢的命中和正确拒绝反应时间，左顶叶新旧效应缺失，以及在识别记忆期间 alpha 和 beta 振荡活动的减少更大。这些结果表明，多巴胺转运体多态性影响识别记忆。
