title: How, when, and where new inhibitory neurons release neurotransmitters in the adult olfactory bulb.
abstract: Adult-born neurons continuously incorporate into the olfactory bulb where they rapidly establish contacts with a variety of synaptic inputs. Little is known, however, about the functional properties of their output. Characterization of synaptic outputs from new neurons is essential to assess the functional impact of adult neurogenesis on mature circuits. Here, we used optogenetics to control neurotransmitter release from new neurons. We found that light-induced synaptic GABA release from adult-born neurons leads to profound modifications of postsynaptic target firing patterns. We revealed that functional output synapses form just after new cells acquire the faculty to spike, but most synapses were made a month later. Despite discrepancies in the timing of new synapse recruitment, the properties of postsynaptic signals remain constant. Remarkably, we found that all major cell types of the olfactory bulb circuit, including output neurons and several distinct subtypes of local interneurons, were contacted by adult-born neurons. Thus, this study provides new insights into how new neurons integrate into the adult neural network and may influence the sense of smell.
authors.affiliation: Laboratory for Perception and Memory, Institut Pasteur, Paris Cedex 15, France.
authors.forename: Cedric
authors.initials: C
authors.lastname: Bardy
authors.forename: Mariana
authors.initials: M
authors.lastname: Alonso
authors.forename: Walid
authors.initials: W
authors.lastname: Bouthour
authors.forename: Pierre-Marie
authors.initials: PM
authors.lastname: Lledo
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D005822:Genetic Vectors; D016086:Lentivirus / Q000235:genetics; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009433:Neural Inhibition / Q000502:physiology*; D055495:Neurogenesis / Q000502:physiology*; D009474:Neurons / Q000378:metabolism* / Q000502:physiology; D009830:Olfactory Bulb / Q000378:metabolism* / Q000502:physiology; D018408:Patch-Clamp Techniques; D010775:Photic Stimulation / Q000379:methods; D009435:Synaptic Transmission / Q000502:physiology; D014162:Transfection / Q000379:methods; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D005680:gamma-Aminobutyric Acid