title: Inhibitory Synapses Are Repeatedly Assembled and Removed at Persistent Sites In Vivo.
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.
authors: Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors: Katherine L
authors: KL
authors: Villa
authors: Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors: Kalen P
authors: KP
authors: Berry
authors: Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors: Jaichandar
authors: J
authors: Subramanian
authors: Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors: Jae Won
authors: JW
authors: Cha
authors: Max Planck Florida Institute for Neuroscience, Jupiter, FL 33458, USA.
authors: Won Chan
authors: WC
authors: Oh
authors: Max Planck Florida Institute for Neuroscience, Jupiter, FL 33458, USA; Max Planck Institute of Neurobiology, Martinsried 82152, Germany.
authors: Hyung-Bae
authors: HB
authors: Kwon
authors: Division of Cerebral Circuitry, National Institute for Physiological Sciences, Okazaki 444-8585, Japan; Department of Physiological Science, Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585, Japan; JST, CREST, Tokyo 102-0076, Japan.
authors: Yoshiyuki
authors: Y
authors: Kubota
authors: Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors: Peter T C
authors: PT
authors: So
authors: Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. Electronic address: nedivi@mit.edu.
authors: Elly
authors: E
authors: Nedivi
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism; D000076122:Disks Large Homolog 4 Protein; D005260:Female; D007839:Functional Laterality; D051528:Guanylate Kinases / Q000235:genetics / Q000378:metabolism; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009433:Neural Inhibition / Q000235:genetics / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D009924:Organ Culture Techniques; D011247:Pregnancy; D017966:Pyramidal Cells / Q000648:ultrastructure*; D012683:Sensory Deprivation; D013569:Synapses / Q000502:physiology* / Q000648:ultrastructure; D009435:Synaptic Transmission / Q000502:physiology*; D014793:Visual Cortex / Q000166:cytology*; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
chemical_list: D002352:Carrier Proteins; D000076122:Disks Large Homolog 4 Protein; C501447:Dlg4 protein, mouse; D008164:Luminescent Proteins; D008565:Membrane Proteins; C073441:gephyrin; D005680:gamma-Aminobutyric Acid; D051528:Guanylate Kinases