title: Rapid and continuous activity-dependent plasticity of olfactory sensory input.
abstract: Incorporation of new neurons enables plasticity and repair of circuits in the adult brain. Adult neurogenesis is a key feature of the mammalian olfactory system, with new olfactory sensory neurons (OSNs) wiring into highly organized olfactory bulb (OB) circuits throughout life. However, neither when new postnatally generated OSNs first form synapses nor whether OSNs retain the capacity for synaptogenesis once mature, is known. Therefore, how integration of adult-born OSNs may contribute to lifelong OB plasticity is unclear. Here, we use a combination of electron microscopy, optogenetic activation and in vivo time-lapse imaging to show that newly generated OSNs form highly dynamic synapses and are capable of eliciting robust stimulus-locked firing of neurons in the mouse OB. Furthermore, we demonstrate that mature OSN axons undergo continuous activity-dependent synaptic remodelling that persists into adulthood. OSN synaptogenesis, therefore, provides a sustained potential for OB plasticity and repair that is much faster than OSN replacement alone.
authors.affiliation: Developmental Neural Plasticity Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, Bethesda, Maryland 20892, USA.
authors.forename: Claire E J
authors.initials: CEJ
authors.lastname: Cheetham
authors.affiliation: Developmental Neural Plasticity Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, Bethesda, Maryland 20892, USA.
authors.forename: Una
authors.initials: U
authors.lastname: Park
authors.affiliation: Developmental Neural Plasticity Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, Bethesda, Maryland 20892, USA.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Belluscio
mesh_terms: D000818:Animals; D005260:Female; D008297:Male; D008822:Mice, Transgenic; D009473:Neuronal Plasticity; D009830:Olfactory Bulb / Q000502:physiology*; D018034:Olfactory Receptor Neurons / Q000502:physiology* / Q000648:ultrastructure; D062308:Optogenetics; D017729:Presynaptic Terminals / Q000502:physiology