Dendritic compartmentalization of input-specific integration and plasticity rules across cortical development

Abstract

SummaryLifelong learning is the ability to continually acquire new information and build upon existing knowledge. Biological and artificial neurons gain and refine internal representations by modifying synaptic weights, but it is unclear how previous knowledge remains stable in spite of ongoing plasticity. Here we show that cortical pyramidal neurons solve this plasticity-stability dilemma by differentially regulating synaptic plasticity within dendritic compartments. We found that oblique dendrites of layer 5 pyramidal neurons in adult mouse primary visual cortex (V1) selectively receive monosynaptic input from dorsal lateral geniculate nucleus (dLGN), integrate linearly, and—surprisingly—lack synaptic potentiation. In contrast, basal dendrites, which do not receive dLGN input, exhibit conventional NMDA receptor (NMDAR)-mediated supralinear integration and synaptic potentiation. Both dendritic compartments initially express NMDAR-mediated supralinear integration and synaptic potentiation during development, but oblique dendritic properties diverge after a critical period of early visual experience. This developmental transition was accompanied by a decrease in relative NMDAR receptor activity and expression at spiny synapses on oblique dendrites. Our results demonstrate a new biological mechanism for how single neurons can safeguard inputs from ongoing experience-dependent plasticity by altering synaptic properties of dendritic domains.