Layer 4 Gates Plasticity in Visual Cortex Independent of a Canonical Microcircuit

• Published in: Current biology Vol. 30; no. 15; pp. 2962 - 2973.e5
• Main Authors: Frantz, Michael G., Crouse, Emily C., Sokhadze, Guela, Ikrar, Taruna, Stephany, Céleste-Élise, Nguyen, Collins, Xu, Xiangmin, McGee, Aaron W.
• Format: Journal Article
• Language: English
• Published: England Elsevier Inc 03-08-2020
• Subjects: amblyopia; Animals; cortical circuit; critical period; Dominance, Ocular; experience-dependent plasticity; Gene Deletion; Mice; myelin; Neuronal Plasticity - physiology; Nogo Receptor 1 - genetics; Nogo Receptor 1 - physiology; ocular dominance; reticulon receptor; Sensory Receptor Cells - physiology; Vision, Binocular - physiology; visual cortex; Visual Cortex - physiology; myelin; experience-dependent plasticity; ocular dominance; cortical circuit; critical period; amblyopia; visual cortex; reticulon receptor
• ISSN: 0960-9822; 1879-0445
• DOI: 10.1016/j.cub.2020.05.067

Disrupting binocular vision during a developmental critical period can yield enduring changes to ocular dominance (OD) in primary visual cortex (V1). Here we investigated how this experience-dependent plasticity is coordinated within the laminar circuitry of V1 by deleting separately in each cortical layer (L) a gene required to close the critical period, nogo-66 receptor (ngr1). Deleting ngr1 in excitatory neurons in L4, but not in L2/3, L5, or L6, prevented closure of the critical period, and adult mice remained sensitive to brief monocular deprivation. Intracortical disinhibition, but not thalamocortical disinhibition, accompanied this OD plasticity. Both juvenile wild-type mice and adult mice lacking ngr1 in L4 displayed OD plasticity that advanced more rapidly L4 than L2/3 or L5. Interestingly, blocking OD plasticity in L2/3 with the drug AM-251 did not impair OD plasticity in L5. We propose that L4 restricts disinhibition and gates OD plasticity independent of a canonical cortical microcircuit.
•Deleting ngr1 in L4, but not L2/3, L5, or L6, sustains OD plasticity in adult mice•Intracortical, but not thalamocortical, disinhibition accompanies OD plasticity•Blocking plasticity in L2/3 with AM-251 does not affect plasticity in L4 or L5
Frantz et al. explore the regulation and propagation of experience-dependent plasticity within the laminar circuitry of visual cortex. Layer 4 limits intracortical disinhibition to close the critical period for OD plasticity throughout visual cortex. OD plasticity does not follow a canonical cortical microcircuit.