Department of Pharmacology, University of Maryland School of Medicine, HSF III 9179, 670 West Baltimore Street, Baltimore, MD, 21201, USA.
Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
Brain Struct Funct. 2019 Sep;224(7):2567-2576. doi: 10.1007/s00429-019-01908-7. Epub 2019 Jun 26.
Striatal fast-spiking interneurons (FSIs) potently inhibit the output neurons of the striatum and, as such, powerfully modulate action learning. Through electrical synaptic coupling, FSIs are theorized to temporally coordinate their activity. This has important implications for their ability to temporally summate inhibition on downstream striatal projection neurons. While some in vivo single-unit electrophysiological recordings of putative FSIs support coordinated firing, others do not. Moreover, it is unclear as to what aspect of action FSIs encode. To address this, we used in vivo calcium imaging of genetically identified FSIs in freely moving mice and applied machine learning analyses to decipher the relationship between FSI activity and movement. We report that FSIs exhibit ensemble activity that encodes the speed of action sub-components, including ambulation and head movements. These results suggest FSI population dynamics fit within a Hebbian model for ensemble inhibition of striatal output guiding action.
纹状体快速放电中间神经元（FSIs）强烈抑制纹状体的输出神经元，从而有力地调节动作学习。通过电突触耦合，FSIs 被理论上认为能够协调它们的活动。这对它们在时间上累加对下游纹状体投射神经元的抑制能力有重要影响。虽然一些体内对 FSIs 的单细胞电生理记录支持协调放电，但其他记录并不支持。此外，尚不清楚 FSIs 编码的动作的哪个方面。为了解决这个问题，我们使用在自由活动的小鼠中对遗传鉴定的 FSIs 进行体内钙成像，并应用机器学习分析来破译 FSI 活性与运动之间的关系。我们报告说，FSIs 表现出的群体活动编码了动作子成分的速度，包括步行和头部运动。这些结果表明，FSI 群体动力学符合一种海伯模型，用于对引导动作的纹状体输出进行抑制的群体抑制。
