Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Faculty of Biology, Jagiellonian University, Krakow 30-387, Poland
Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Faculty of Biology, Jagiellonian University, Krakow 30-387, Poland.
eNeuro. 2024 Mar 26;11(3). doi: 10.1523/ENEURO.0490-23.2023. Print 2024 Mar.
The motor cortex comprises the primary descending circuits for flexible control of voluntary movements and is critically involved in motor skill learning. Motor skill learning is impaired in patients with Parkinson's disease, but the precise mechanisms of motor control and skill learning are still not well understood. Here we have used transgenic mice, electrophysiology, in situ hybridization, and neural tract-tracing methods to target genetically defined cell types expressing D1 and D2 dopamine receptors in the motor cortex. We observed that putative D1 and D2 dopamine receptor-expressing neurons (D1+ and D2+, respectively) are organized in highly segregated, nonoverlapping populations. Moreover, based on ex vivo patch-clamp recordings, we showed that D1+ and D2+ cells have distinct morphological and electrophysiological properties. Finally, we observed that chemogenetic inhibition of D2+, but not D1+, neurons disrupts skilled forelimb reaching in adult mice. Overall, these results demonstrate that dopamine receptor-expressing cells in the motor cortex are highly segregated and play a specialized role in manual dexterity.
运动皮层包含用于灵活控制自主运动的主要下行回路，并且在运动技能学习中起着至关重要的作用。运动技能学习在帕金森病患者中受损，但运动控制和技能学习的确切机制仍未得到很好的理解。在这里，我们使用转基因小鼠、电生理学、原位杂交和神经束追踪方法，针对在运动皮层中表达 D1 和 D2 多巴胺受体的遗传定义的细胞类型进行靶向。我们观察到，假定的 D1 和 D2 多巴胺受体表达神经元（分别为 D1+和 D2+）组织在高度隔离、不重叠的群体中。此外，基于离体膜片钳记录，我们表明 D1+和 D2+细胞具有不同的形态和电生理特性。最后，我们观察到化学遗传抑制 D2+，而不是 D1+，神经元会破坏成年小鼠熟练的前肢伸展。总的来说，这些结果表明运动皮层中的多巴胺受体表达细胞高度隔离，并在手灵巧性中发挥专门作用。
