Institute for Cognitive Science Studies (ICSS), Tehran, Iran.
Department of Stem Cells and Regenerative Medicine, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran.
Acta Neurobiol Exp (Wars). 2021;81(2):171-180.
Evidence suggests that transcranial direct current stimulation (tDCS) modulates conditioned fear memories and has effects on cognitive flexibility via the dopaminergic system. This study examines whether modulation of scopolamine‑induced fear memory deficit by anodal tDCS could be mediated by the dopaminergic system. The male NMRI mice received scopolamine, 30 min before fear conditioning, and showed impaired contextual memory retention. Mice subjected to left frontal anodal stimulation for 20 or 30 min, before fear conditioning, impaired fear memory retrieval. Anodal application for 20 min significantly decreased scopolamine response on fear retention, while the one applied for 30 min did not alter. Moreover, anodal stimulation for 30 min abolished scopolamine‑induced fear memory deficit. Dopaminergic antagonists SCH23390 and sulpiride, alone or in combination, prevented the abolishment effect of anodal stimulation on scopolamine‑induced fear memory deficit, whereas they did not alter the impairing effect of scopolamine at the dose of 2 mg/kg. Our data suggest that anodal stimulation for 30 min abrogates the impairing effect of scopolamine on fear memory retention. This influence could be prevented by dopaminergic antagonists, indicating the involvement of the dopaminergic system in the effect of anodal stimulation on scopolamine‑induced fear memory deficit.
有证据表明，经颅直流电刺激（tDCS）通过多巴胺能系统调节条件性恐惧记忆，并对认知灵活性产生影响。本研究探讨了左侧额极经阳极刺激是否可以通过多巴胺能系统来调节东莨菪碱诱导的恐惧记忆缺陷。雄性 NMRI 小鼠在恐惧条件反射前 30 分钟接受东莨菪碱处理，表现出情景记忆保留受损。在恐惧条件反射前进行 20 或 30 分钟的左侧额极阳极刺激会损害恐惧记忆的检索。阳极刺激 20 分钟可显著降低东莨菪碱对恐惧保留的反应，而刺激 30 分钟则没有改变。此外，阳极刺激 30 分钟可消除东莨菪碱诱导的恐惧记忆缺陷。多巴胺能拮抗剂 SCH23390 和舒必利单独或联合使用可防止阳极刺激对东莨菪碱诱导的恐惧记忆缺陷的消除作用，而它们在 2mg/kg 的剂量下不会改变东莨菪碱的损害作用。我们的数据表明，阳极刺激 30 分钟可消除东莨菪碱对恐惧记忆保留的损害作用。这种影响可以被多巴胺能拮抗剂所阻止，表明多巴胺能系统参与了阳极刺激对东莨菪碱诱导的恐惧记忆缺陷的影响。
