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

Courtney E Yaeger, Dimitra Vardalaki, Norma J Brown, Mark T Harnett
2022 bioRxiv   pre-print
The modification of synaptic weights is critical for learning, while synaptic stability is required to maintain acquired knowledge. Single neurons have thousands of synapses within their dendritic arbors, and how the weights of specific inputs change across experience is poorly understood. Here we report that dendritic compartments receiving input from different presynaptic populations acquire distinct synaptic plasticity and integration rules across maturation. We find that apical oblique
more » ... ites of layer 5 pyramidal neurons in adult mouse primary visual cortex receive direct monosynaptic projections from the dorsal lateral geniculate nucleus (dLGN), linearly integrate input, and lack synaptic potentiation. In contrast, basal dendrites, which do not receive dLGN input, exhibit NMDA receptor (NMDAR)-mediated supralinear integration and synaptic potentiation. Earlier in development, during thalamic input refinement, oblique and basal dendrites exhibited comparable NMDAR-dependent properties. Oblique dendrites gain mature properties with visual experience, and over the course of maturation, spines on oblique dendrites develop higher AMPA/NMDA ratios relative to basal dendrites. Our results demonstrate that cortical neurons possess dendrite-specific integration and plasticity rules that are set by the activity of their inputs. The linear, non-plastic nature of mature synapses on oblique dendrites may stabilize feedforward sensory processing while synaptic weights in other parts of the dendritic tree remain plastic, facilitating robust yet flexible cortical computation in adults.
doi:10.1101/2022.02.02.478840 fatcat:555blaxwsraqtf3ymn3paeg2ha