Wilkerson A, Levin E D
Department of Psychiatry, Duke University Medical Center, Durham, NC 27710, USA.
Neuroscience. 1999 Mar;89(3):743-9. doi: 10.1016/s0306-4522(98)00346-7.
The hippocampus has long been known to be important for memory function. However, the involvement of hippocampal dopamine systems with memory has received little attention. In the current study, dopamine D1 and D2 hippocampal receptor system involvement with memory was assessed in female Sprague-Dawley rats by local infusion of D1 and D2 agonists and antagonists into the ventral hippocampus. Working memory performance was assessed on the radial-arm maze. Neither the D1 agonist dihydrexidine (1.1-10 microg/side) nor the D1 antagonist SCH 23390 (0.19-1.67 microg/side) was effective in significantly altering radial-arm maze choice accuracy. In contrast, there were significant and opposite effects of D2 agonist and antagonist treatments. The D2 agonist quinpirole caused a significant (P<0.05) dose-related improvement in choice accuracy over a dose range of 1.1-10 microg/side. In a complementary fashion, the D2 antagonist raclopride caused a significant (P<0.05) dose-related choice accuracy deficit over a range of 0.19-1.67 microg/side. This study provides clear evidence that hippocampal D2 activity is positively related to working memory performance, while evidence for D1 systems is less compelling. Dopamine D2 receptors in the ventral hippocampus were shown to have important influences on spatial working memory. In a consistent pattern of effects ventral hippocampal infusion of the D2 agonist quinpirole improved working memory performance in the radial-arm maze, while ventral hippocampal infusion of the D2 antagonist raclopride impaired performance.
长期以来，人们一直认为海马体对记忆功能很重要。然而，海马体多巴胺系统与记忆的关系却很少受到关注。在当前的研究中，通过向雌性斯普拉格-道利大鼠的腹侧海马体局部注射D1和D2激动剂及拮抗剂，评估了海马体多巴胺D1和D2受体系统与记忆的关系。在放射状臂迷宫上评估工作记忆表现。D1激动剂二氢麦角隐亭（1.1 - 10微克/侧）和D1拮抗剂SCH 23390（0.19 - 1.67微克/侧）均未显著改变放射状臂迷宫选择的准确性。相比之下，D2激动剂和拮抗剂处理产生了显著且相反的效果。D2激动剂喹吡罗在1.1 - 10微克/侧的剂量范围内，使选择准确性有显著的（P<0.05）剂量相关改善。以互补的方式，D2拮抗剂雷氯必利在0.19 - 1.67微克/侧的范围内，导致了显著的（P<0.05）剂量相关的选择准确性缺陷。这项研究提供了明确的证据，表明海马体D2活性与工作记忆表现呈正相关，而D1系统的证据则不那么有说服力。腹侧海马体中的多巴胺D2受体对空间工作记忆有重要影响。在一致的效应模式中，腹侧海马体注射D2激动剂喹吡罗可改善放射状臂迷宫中的工作记忆表现，而腹侧海马体注射D2拮抗剂雷氯必利则损害表现。
