Inhibitory Synapses Are Repeatedly Assembled and Removed at Persistent Sites In Vivo

Katherine L. Villa, Kalen P. Berry, Jaichandar Subramanian, Jae Won Cha, Won Chan Oh, Hyungbae Kwon, Yoshiyuki Kubota, Peter T.C. So, Elly Nedivi

Research output: Contribution to journalArticle

Abstract

Older concepts of a hard-wired adult brain have been overturned in recent years by in vivo imaging studies revealing synaptic remodeling, now thought to mediate rearrangements in microcircuit connectivity. Using three-color labeling and spectrally resolved two-photon microscopy, we monitor in parallel the daily structural dynamics (assembly or removal) of excitatory and inhibitory postsynaptic sites on the same neurons in mouse visual cortex in vivo. We find that dynamic inhibitory synapses often disappear and reappear again in the same location. The starkest contrast between excitatory and inhibitory synapse dynamics is on dually innervated spines, where inhibitory synapses frequently recur while excitatory synapses are stable. Monocular deprivation, a model of sensory input-dependent plasticity, shortens inhibitory synapse lifetimes and lengthens intervals to recurrence, resulting in a new dynamic state with reduced inhibitory synaptic presence. Reversible structural dynamics indicate a fundamentally new role for inhibitory synaptic remodeling-flexible, input-specific modulation of stable excitatory connections. Synaptic remodeling observed in vivo is commonly thought to represent rearrangements in microcircuit connectivity. Villa et al. observe a new, reversible type of synapse dynamics, unique to inhibitory synapses, which could provide flexible, input-specific gating of stable excitatory connections.

Original languageEnglish (US)
Pages (from-to)756-769
Number of pages14
JournalNeuron
Volume89
Issue number4
DOIs
Publication statusPublished - Feb 17 2016
Externally publishedYes

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ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

Villa, K. L., Berry, K. P., Subramanian, J., Cha, J. W., Oh, W. C., Kwon, H., ... Nedivi, E. (2016). Inhibitory Synapses Are Repeatedly Assembled and Removed at Persistent Sites In Vivo. Neuron, 89(4), 756-769. https://doi.org/10.1016/j.neuron.2016.01.010