Houser Grace, Vieites Prado Alba, Topilko Thomas, Nguyen Clara, Gaspar Patricia, Renier Nicolas
Sorbonne Université, Paris Brain Institute - ICM, INSERM, CNRS, AP-HP, Hôpital de la Pitié Salpêtrière, Paris, France.
iScience. 2025 May 21;28(6):112725. doi: 10.1016/j.isci.2025.112725. eCollection 2025 Jun 20.
Sensory information travels from the periphery to the cortex across relays. Each of these stations receives feedback projections which gate and tune the transmission of feedforward information. We used whole brain imaging combined with viral strategies and single axon tracings to reveal the existence of a bilateral feedback projection from the somatosensory cortex to brainstem relays processing whisker information. Initially, after birth in mice, this feedback loop projects equally to both sides of the brainstem. Then, the projection strengthens preferentially toward the contralateral side while maintaining its ipsilateral component. We found that manipulating the laterality of the feedforward pathway from the brainstem to the opposite cortex altered the laterality preference of the descending feedback projections. This suggests a dynamic interplay between ascending and descending pathways in shaping sensory processing. This study highlights the presence of bilateral integration within the somatosensory system's feedback projections.
感觉信息通过中继从外周传递到皮层。这些站点中的每一个都接收反馈投射，这些投射对前馈信息的传递进行门控和调节。我们使用全脑成像结合病毒策略和单轴突追踪来揭示从体感皮层到处理触须信息的脑干中继存在双侧反馈投射。最初，在小鼠出生后，这个反馈回路平等地投射到脑干的两侧。然后，该投射优先向对侧增强，同时保留其同侧成分。我们发现，操纵从脑干到对侧皮层的前馈通路的偏侧性会改变下行反馈投射的偏侧性偏好。这表明在塑造感觉处理过程中，上行和下行通路之间存在动态相互作用。这项研究突出了体感系统反馈投射中双侧整合的存在。
