Department of Molecular and Cell Biology and Helen Wills Neuroscience Institute, University of California, Berkeley, 142 Life Science Addition #3200, CA 94720, USA.
Department of Molecular and Cell Biology and Helen Wills Neuroscience Institute, University of California, Berkeley, 142 Life Science Addition #3200, CA 94720, USA.
Neuron. 2018 Jan 17;97(2):434-449.e4. doi: 10.1016/j.neuron.2017.12.022. Epub 2018 Jan 4.
Mesolimbic dopamine (DA) neurons play a central role in motivation and reward processing. Although the activity of these mesolimbic DA neurons is controlled by afferent inputs, little is known about the circuits in which they are embedded. Using retrograde tracing, electrophysiology, optogenetics, and behavioral assays, we identify principles of afferent-specific control in the mesolimbic DA system. Neurons in the medial shell subdivision of the nucleus accumbens (NAc) exert direct inhibitory control over two separate populations of mesolimbic DA neurons by activating different GABA receptor subtypes. In contrast, NAc lateral shell neurons mainly synapse onto ventral tegmental area (VTA) GABA neurons, resulting in disinhibition of DA neurons that project back to the NAc lateral shell. Lastly, we establish a critical role for NAc subregion-specific input to the VTA underlying motivated behavior. Collectively, our results suggest a distinction in the incorporation of inhibitory inputs between different subtypes of mesolimbic DA neurons.
中脑边缘多巴胺(DA)神经元在动机和奖励处理中发挥核心作用。尽管这些中脑边缘 DA 神经元的活动受到传入输入的控制,但对于它们所在的回路知之甚少。通过逆行追踪、电生理学、光遗传学和行为分析,我们确定了中脑边缘 DA 系统中传入特定控制的原则。伏隔核(NAc)内侧壳亚区的神经元通过激活不同的 GABA 受体亚型,对两个独立的中脑边缘 DA 神经元群施加直接抑制控制。相比之下,NAc 外侧壳神经元主要与腹侧被盖区(VTA)GABA 神经元形成突触,导致投射回 NAc 外侧壳的 DA 神经元去抑制。最后,我们确定了 NAc 亚区特异性输入对 VTA 驱动行为的关键作用。总的来说,我们的研究结果表明,不同亚型的中脑边缘 DA 神经元对抑制性输入的整合存在差异。