Neuron. 2026 Feb 17:S0896-6273(25)00976-6. doi: 10.1016/j.neuron.2025.12.020. Online ahead of print.
ABSTRACT
Sensory processing enables adaptive behavior by accurately encoding dynamic environmental stimuli. Within thalamocortical (TC) circuits, the thalamic reticular nucleus (TRN) functions as a key inhibitory gate that regulates cortical access to sensory input. While classical models posit that sensory circuits stabilize after early critical periods, we uncover a previously unrecognized phase of synaptic refinement in TRN circuitry extending from the juvenile period into adulthood. This late-stage remodeling is driven by a progressive reduction in corticothalamic (CT) excitatory input and is essential for enhancing sensory gain, response linearity, and stimulus discriminability. We identify LRRTM3, a TRN-enriched synaptic adhesion molecule, as a molecular gatekeeper of this process. TRN-specific deletion of LRRTM3 disrupts CT-TRN refinement, elevates TRN-mediated inhibition, and impairs fine tactile discrimination. These findings revise canonical views of sensory circuit maturation, revealing that LRRTM3-mediated juvenile-to-adult TRN plasticity is essential for the emergence of high-resolution sensory encoding in the adult brain.
PMID:41709459 | DOI:10.1016/j.neuron.2025.12.020