Neurobiology Section, Center for Neural Circuits and Behavior, and Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA.
Neurobiology Section, Center for Neural Circuits and Behavior, and Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA.
Neuron. 2019 Dec 18;104(6):1126-1140.e6. doi: 10.1016/j.neuron.2019.09.028. Epub 2019 Nov 6.
The posterior parietal cortex (PPC) performs many functions, including decision making and movement control. It remains unknown which input and output pathways of PPC support different functions. We addressed this issue in mice, focusing on PPC neurons projecting to the dorsal striatum (PPC-STR) and the posterior secondary motor cortex (PPC-pM2). Projection-specific, retrograde labeling showed that PPC-STR and PPC-pM2 represent largely distinct subpopulations, with PPC-STR receiving stronger inputs from association areas and PPC-pM2 receiving stronger sensorimotor inputs. Two-photon calcium imaging during decision making revealed that the PPC-STR population encodes history-dependent choice bias more strongly than PPC-pM2 or general PPC populations. Furthermore, optogenetic inactivation of PPC-STR neurons or their terminals in STR decreased history-dependent bias, while inactivation of PPC-pM2 neurons altered movement kinematics. Therefore, PPC biases action selection through its STR projection while controlling movements through PPC-pM2 neurons. PPC may support multiple functions through parallel subpopulations, each with distinct input-output connectivity.
后顶叶皮层（PPC）执行多种功能，包括决策和运动控制。目前尚不清楚支持不同功能的 PPC 的输入和输出途径是哪些。我们在小鼠中解决了这个问题，重点关注投射到背侧纹状体（PPC-STR）和后次级运动皮层（PPC-pM2）的 PPC 神经元。针对特定投射的逆行标记显示，PPC-STR 和 PPC-pM2 代表了很大程度上不同的亚群，其中 PPC-STR 从联合区接收更强的输入，而 PPC-pM2 接收更强的感觉运动输入。在决策过程中的双光子钙成像显示，PPC-STR 群体比 PPC-pM2 或一般的 PPC 群体更强烈地编码历史相关的选择偏好。此外，STR 中 PPC-STR 神经元或其末梢的光遗传学失活降低了历史相关的偏好，而 PPC-pM2 神经元的失活改变了运动运动学。因此，PPC 通过其 STR 投射来影响动作选择，同时通过 PPC-pM2 神经元来控制运动。PPC 可能通过平行的亚群支持多种功能，每个亚群都具有独特的输入-输出连接。
