Estrogens, particularly 17β-estradiol (estradiol, E₂), regulate memory formation. E2 acts through its intracellular receptors, estrogen receptors (ER) ERα and ERβ, as well as a recently identified G protein-coupled estrogen receptor (GPER). Although the effects of E2 on memory have been investigated, studies examining the effects of GPER stimulation are scarce. Selective GPER agonism improves memory in ovariectomized female rats, but little information is available regarding the effects of GPER stimulation in male rodents. The aim of the present study was to investigate the effects of the GPER agonist, G1, on consolidation and reconsolidation of inhibitory avoidance (IA) and object recognition (OR) memory in male rats. Animals received vehicle, G1 (15, 75, 150 µg/kg; i.p.), or the GPER antagonist G15 (100 µg/kg; i.p.) immediately after training, or G1 (150 µg/kg; i.p.) 3 or 6 h after training. To investigate reconsolidation, G1 was administered immediately after IA retention Test 1. Results indicated that G1 administered immediately after training at the highest dose enhanced both OR and IA memory consolidation, while GPER blockade immediately after training impaired OR. No effects of GPER stimulation were observed when G1 was given 3 or 6 h after training or after Test 1. The present findings provide evidence that GPER is involved in the early stages of memory consolidation in both neutral and emotional memory tasks in male adult rats.

雌激素，尤其是 17β-雌二醇（雌二醇，E ₂)，调节记忆的形成。E2 通过其细胞内受体、雌激素受体 (ER) ERα 和 ERβ 以及最近发现的 G 蛋白偶联雌激素受体 (GPER) 发挥作用。尽管已经研究了 E2 对记忆的影响，但研究 GPER 刺激的影响的研究很少。选择性 GPER 激动剂可改善卵巢切除雌性大鼠的记忆力，但关于 GPER 刺激对雄性啮齿动物的影响的信息很少。本研究的目的是研究 GPER 激动剂 G1 对雄性大鼠抑制性回避 (IA) 和对象识别 (OR) 记忆的巩固和再巩固的影响。动物在训练后立即接受载体、G1（15、75、150 µg/kg；ip）或 GPER 拮抗剂 G15（100 µg/kg；ip），或在训练后 3 或 6 小时接受 G1（150 µg/kg；ip）训练。为了研究再巩固，在 IA 保留测试 1 后立即给予 G1。结果表明，在最高剂量训练后立即给予 G1 增强 OR 和 IA 记忆巩固，而训练后立即阻断 GPER 损害 OR。在训练后 3 或 6 小时或测试 1 后给予 G1 时，未观察到 GPER 刺激的影响。本研究结果提供证据表明 GPER 参与了雄性成年大鼠中性和情绪记忆任务中记忆巩固的早期阶段。