Agustín-Pavón Carmen, Martínez-Ricós Joana, Martínez-García Fernando, Lanuza Enrique
Department of Cell Biology, Facultat de Ciencies Biologiques, Universitat de Valencia, Valencia, Spain.
Behav Neurosci. 2007 Oct;121(5):920-32. doi: 10.1037/0735-7044.121.5.920.
Male sexual pheromones are innately rewarding to adult female mice, but the role of dopamine in this natural reward is unknown. The authors have tackled this issue by assessing the effects of intraperitoneal injections of dopamine D1 (SCH 23390, 0.02- 0.05 mg/kg) and D2 (sulpiride, 20.00 mg/kg) antagonists, a dopamine releasing agent (amphetamine, 0.50 -2.00 mg/kg), and D1 (SKF 38393, 10.00 -20.00 mg/kg) and D2 (quinpirole, 0.20 -1.00 mg/kg) agonists on the chemoinvestigation displayed by female mice in male- versus female-soiled bedding 2-choice tests. Dopamine antagonists and quinpirole failed to affect the unconditioned preference displayed by females towards male chemosignals, whereas both amphetamine and SKF 38393 abolished it. Finally, D1 and D2 antagonists did not block the induction of operant place conditioning by male chemosignals. As the female mice were tested in their first encounter with male sexual pheromones, their behavior can only be influenced by the "liking" component of reward. Therefore, the results suggest that dopamine mediates neither the hedonic properties of male sexual pheromones nor the acquisition of conditioned place preference. However, dopamine acting on D1 receptors might inhibit female mice attraction towards male chemosignals.
雄性性信息素对成年雌性小鼠具有内在的奖赏作用，但多巴胺在这种自然奖赏中的作用尚不清楚。作者通过评估腹腔注射多巴胺D1拮抗剂（SCH 23390，0.02 - 0.05毫克/千克）、D2拮抗剂（舒必利，20.00毫克/千克）、多巴胺释放剂（苯丙胺，0.50 - 2.00毫克/千克）以及D1激动剂（SKF 38393，10.00 - 20.00毫克/千克）和D2激动剂（喹吡罗，0.20 - 1.00毫克/千克）对雌性小鼠在雄性与雌性弄脏的垫料二选一测试中表现出的化学探究行为的影响，来解决这个问题。多巴胺拮抗剂和喹吡罗未能影响雌性小鼠对雄性化学信号表现出的无条件偏好，而苯丙胺和SKF 38393都消除了这种偏好。最后，D1和D2拮抗剂并未阻断雄性化学信号对操作性位置条件反射的诱导。由于雌性小鼠是在首次接触雄性性信息素时接受测试的，它们的行为只能受奖赏的“喜好”成分影响。因此，结果表明多巴胺既不介导雄性性信息素的享乐特性，也不介导条件性位置偏好的习得。然而，作用于D1受体的多巴胺可能会抑制雌性小鼠对雄性化学信号的吸引力。
