Becker Elizabeth A, Marler Catherine A
Department of Psychology, University of Wisconsin- Madison.
Behav Neurosci. 2015 Apr;129(2):205-13. doi: 10.1037/bne0000043.
The winner effect is an accumulation of previous wins that increase future winning. A primary unanswered question about the winner effect is how do individuals integrate information about previous wins? Dopamine (DA) has been implicated because phosphorylated tyrosine hydroxylase (pTH), the rate-limiting enzyme for DA biosynthesis, is elevated following multiple winning experiences. Moreover, DA receptor blockers and agonists influence aggression when administered prior to male-male contests. In the current study, we administered D1- and D2-like DA receptor antagonists immediately after a contest and examined the development of the winner effect in the territorial California mouse, Peromyscus californicus. During a 3-contest training phase, resident males experienced winning contests, followed immediately by a peripheral injection of either a DA receptor antagonist or vehicle or a handling experience (without injection). The DA receptor antagonists used in this study did not influence locomotion. To assess the cumulative effects of previous winning, males were subjected to a final test contest with a more competitive intruder. The winner effect was significantly decreased by both D1- and D2-like receptor antagonists administered during training. During the test contest, attack behavior was significantly reduced by previous administration of both types of DA receptor antagonists compared with controls. D1-like receptor blockade also diminished chasing behavior, whereas D2-antagonist treated animals continued to pursue opponents. During training against a less competitive intruder, there was no difference in aggressive behaviors between experimental and controls males. Our data indicate that DA activity between contests is concomitant with the competitive advantage gained from multiple winning experiences.
胜者效应是指先前胜利的积累会增加未来获胜的几率。关于胜者效应一个主要的未解决问题是个体如何整合有关先前胜利的信息？多巴胺（DA）被认为与此有关，因为DA生物合成的限速酶磷酸化酪氨酸羟化酶（pTH）在多次胜利经历后会升高。此外，在雄性对雄性的争斗之前给予DA受体阻滞剂和激动剂会影响攻击性。在本研究中，我们在一场争斗后立即给予D1和D2样DA受体拮抗剂，并研究领地性加州小鼠（加州林鼠）胜者效应的发展。在一个三场争斗的训练阶段，作为领地所有者的雄性小鼠经历胜利的争斗，随后立即进行外周注射，注射的要么是DA受体拮抗剂，要么是赋形剂，要么是进行一次处理（不注射）。本研究中使用的DA受体拮抗剂不影响运动。为了评估先前胜利的累积效应，让雄性小鼠与一个更具竞争力的入侵者进行一场最终测试争斗。训练期间给予的D1和D2样受体拮抗剂均显著降低了胜者效应。在测试争斗中，与对照组相比，先前给予这两种类型的DA受体拮抗剂均显著降低了攻击行为。D1样受体阻断也减少了追逐行为，而用D2拮抗剂处理的动物继续追逐对手。在与竞争力较弱的入侵者的训练中，实验雄性小鼠和对照雄性小鼠之间的攻击行为没有差异。我们的数据表明，争斗之间的DA活性与从多次胜利经历中获得的竞争优势相伴。
