A prenatal window for enhancing spatial resolution of cortical barrel maps

This is the authors' abstract. We don't add key points for this paper.

Precise mapping of peripheral inputs onto cortical areas is essential for accurate sensory processing. In the mouse primary somatosensory cortex, mystacial whiskers correspond to large, well-defined barrels, while upper lip whiskers form smaller, less distinct barrels. These differences are traditionally attributed to variations in whisker input type and receptor density, but prenatal activity and transcriptional programs also impact somatosensory map development independently of sensory experience. Here, we demonstrate that prenatal ablation of mystacial whiskers leads to a remapping of cortical territories, enhancing the functional and anatomical definition of upper lip whisker barrels. This reorganization occurs without altering peripheral receptor types. Instead, thalamic neurons that receive upper lip inputs adopt a mystacial-like transcriptional profile. Our findings unveil a regulated prenatal mechanism in the thalamus that ensures sufficient cortical barrel size and spatial resolution for sensory processing, irrespective of peripheral receptor type or density, highlighting a critical developmental process in sensory mapping. Neural mechanisms underlying the construction of distinct barrel maps, and to what extent they rely on the type of sensory receptors are not fully understood. Here authors show that prenatal mystacial whisker ablation triggers a thalamic mechanism that rescales cortical territories, refining upper lip whisker barrels and enhancing sensory resolution, emphasizing a critical developmental process in sensory mapping.