Increased phasic dopamine signaling in the mesolimbic pathway during social defeat in rats.
Increased phasic dopamine signaling in the mesolimbic pathway during social defeat in rats.
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DOI：
10.1016/j.neuroscience.2009.03.023
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发表时间：
2009-06-16
期刊：
影响因子：
3.3
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中科院分区：
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虽然在细胞体和终末都清楚地证明了多巴胺信号相的奖赏依赖的易化，但关于在厌恶条件下的快速多巴胺传递却知之甚少。对于包括老鼠在内的许多物种来说，暴露在咄咄逼人的对抗中是极其令人厌恶和紧张的。本研究采用快速扫描循环伏安法和多单位记录的方法来确定攻击和随后的社会失败是否会影响战败大鼠腹侧被盖区(VTA)多巴胺神经元和伏隔多巴胺瞬变的爆发放电。在与攻击性大鼠的相互作用中，观察到瞬时多巴胺释放的频率显著增加，但与熟悉的笼友没有观察到。与伏安法结果一致的是，在一场攻击性对抗中，VTA多巴胺放电模式的爆发频率显著增加；然而，每次爆发的尖峰次数保持不变。我们发现，在归巢条件下，爆发率较低的神经元不会从非爆发型转换为爆发型，而爆发水平较高的神经元在爆发型中表现出放大的增加。这项研究首次证明了战败大鼠的攻击性对抗与中脑边缘通路中相多巴胺传递的增加有关。
While reward-dependent facilitation of phasic dopamine signaling is well documented at both the cell bodies and terminals, little is known regarding fast dopamine transmission under aversive conditions. Exposure to aggressive confrontation is extremely aversive and stressful for many species including rats. The present study used fast-scan cyclic voltammetry and multiunit recording to determine if aggressive encounters and subsequent social defeat affect burst firing of ventral tegmental area (VTA) dopamine neurons and accumbal dopamine transients in defeated rats. Significant increases in the frequency of transient dopamine release were observed during interactions with an aggressive rat but not with a familiar cage mate. In agreement with voltammetric results, significant increases in burst frequency were detected in the VTA dopamine firing patterns during an aggressive confrontation; however, the number of spikes per burst remained unchanged. We found that neurons with lower burst rates under homecage conditions did not switch from non-bursting to bursting types, while neurons with higher burst levels showed amplified increases in bursting. This study demonstrates for the first time that aggressive confrontations in defeated rats are associated with increases in phasic dopamine transmission in the mesolimbic pathway.