Laboratory of Sensory Processing, Brain Mind Institute, Faculty of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), EPFL-SV-BMI-LSENS Station 19, CH-1015, Lausanne, Switzerland.
Department of Basic Neurosciences, Faculty of Medicine, University of Geneva, 1 Rue Michel-Servet, 1206, Geneva, Switzerland.
Nat Commun. 2020 Jul 3;11(1):3342. doi: 10.1038/s41467-020-17087-7.
Subdivisions of mouse whisker somatosensory thalamus project to cortex in a region-specific and layer-specific manner. However, a clear anatomical dissection of these pathways and their functional properties during whisker sensation is lacking. Here, we use anterograde trans-synaptic viral vectors to identify three specific thalamic subpopulations based on their connectivity with brainstem. The principal trigeminal nucleus innervates ventral posterior medial thalamus, which conveys whisker-selective tactile information to layer 4 primary somatosensory cortex that is highly sensitive to self-initiated movements. The spinal trigeminal nucleus innervates a rostral part of the posterior medial (POm) thalamus, signaling whisker-selective sensory information, as well as decision-related information during a goal-directed behavior, to layer 4 secondary somatosensory cortex. A caudal part of the POm, which apparently does not receive brainstem input, innervates layer 1 and 5A, responding with little whisker selectivity, but showing decision-related modulation. Our results suggest the existence of complementary segregated information streams to somatosensory cortices.
鼠标触须体感丘脑的细分区域以特定于区域和特定于层的方式投射到皮质。然而，在触须感觉过程中，这些途径及其功能特性的明确解剖仍然缺乏。在这里，我们使用顺行跨突触病毒载体，根据与脑干的连接，基于连接性将三个特定的丘脑亚群识别出来。主要的三叉神经核支配腹后内侧丘脑，该丘脑将触须选择性触觉信息传递到对自我发起运动高度敏感的初级体感皮层的第 4 层。脊髓三叉神经核支配后内侧（POm）丘脑的前部，向第 4 层次级体感皮层传递触须选择性感觉信息以及目标导向行为过程中的决策相关信息。POm 的后部显然没有接收脑干输入，支配第 1 层和第 5A 层，对触须的选择性反应很小，但显示出与决策相关的调制。我们的结果表明存在与体感皮层互补的分离信息流。
