Modulation of hippocampal and amygdalar-evoked activity of nucleus accumbens neurons by dopamine: Cellular mechanisms of input selection
Modulation of hippocampal and amygdalar-evoked activity of nucleus accumbens neurons by dopamine: Cellular mechanisms of input selection
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DOI：
10.1523/jneurosci.21-08-02851.2001
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发表时间：
2001-04-15
影响因子：
5.3
通讯作者：
Phillips, AG
中科院分区：
文献类型：
--
作者：
Floresco, SB;Blaha, CD;Phillips, AG
来自端脑多个部位的输入，包括海马和基底外侧杏仁核（BLA），汇聚在脑桥核（NAc）的神经元上，多巴胺（DA）被认为在这些不同边缘系统输入的放大和门控中起重要作用。本研究采用细胞外单单位记录的NAc神经元结合计时电流采样的mesoadenbens DA流出，以评估DA的重要性，在不同的边缘系统输入的NAc的整合。强直刺激海马伞增强了海马诱发的NAG神经元放电活动，并增加了DA细胞外水平。D-1受体拮抗剂SCH 23390或NMDA受体拮抗剂CPP的全身给药取消了增强的海马诱发活动，并产生了D-2受体介导的抑制诱发放电。在接受来自海马和BLA的会聚输入的神经元中，破伤风菌毛增强了海马诱发的放电活动，并抑制了相同神经元中的BLA诱发的活动。D-1受体和NMDA受体都参与了纤毛诱发活动的增强，而对BLA-E诱发活动的抑制可被SCH 23390或腺苷A（1）拮抗剂8-环戊基-1，2-二甲基黄嘌呤（8-cyclopentyl-1，2-dimethylxanthine）阻断。偶然破伤风的菌毛和BLA导致两个输入的增强，表明DA和腺苷介导的抑制BLA诱发的放电是活动依赖性的。这些数据表明，增加中脑DA流出的海马传入NAc在输入选择机制中发挥了关键作用，这可以确保优先响应从海马到腹侧纹状体的信息。
Inputs from multiple sites in the telencephalon, including the hippocampus and basolateral amygdala (BLA), converge on neurons in the nucleus accumbens (NAc), and dopamine (DA) is believed to play an essential role in the amplification and gating of these different limbic inputs. The present study used extracellular single-unit recordings of NAc neurons in combination with chronoamperometric sampling of mesoaccumbens DA efflux to assess the importance of DA in the integration of different limbic inputs to the NAc. Tetanic stimulation of the fimbria potentiated hippocampal-evoked firing activity of NAG neurons and increased DA extracellular levels. Systemic administration of the D-1 receptor antagonist SCH23390 or the NMDA receptor antagonist CPP abolished the potentiation of hippocampal-evoked activity and produced a D-2 receptor-mediated suppression of evoked firing. In neurons that received converging input from the hippocampus and BLA, fimbria tetanus potentiated hippocampal-evoked firing activity and suppressed BLA-evoked activity in the same neurons. Both D-1 and NMDA receptors participated in the potentiation of fimbria-evoked activity, whereas the suppression of BLA-evoked activity was blocked by either D-1 receptor antagonism with SCH23390 or the adenosine A(1) antagonist 8-cyclopentyl-1,2-dimethylxanthine. Coincidental tetanus of both the fimbria and BLA resulted in potentiation of both inputs, indicating that DA and adenosine-mediated suppression of BLA-evoked firing was activity-dependent. These data suggest that increases in mesoaccumbens DA efflux by hippocampal afferents to the NAc play a critical role in an input selection mechanism, which can ensure preferential responding to the information conveyed from the hippocampus to the ventral striatum.