Parvalbumin-expressing interneurons linearly control olfactory bulb output.
In the olfactory bulb, odor representations by principal mitral cells are modulated by local inhibitory circuits. While dendrodendritic synapses between mitral and granule cells are typically thought to be a major source of this modulation, the contributions of other inhibitory neurons remain unclear. Here we demonstrate the functional properties of olfactory bulb parvalbumin-expressing interneurons (PV cells) and identify their important role in odor coding. Using paired recordings, we find that PV cells form reciprocal connections with the majority of nearby mitral cells, in contrast to the sparse connectivity between mitral and granule cells. In vivo calcium imaging in awake mice reveals that PV cells are broadly tuned to odors. Furthermore, selective PV cell inactivation enhances mitral cell responses in a linear fashion while maintaining mitral cell odor preferences. Thus, dense connections between mitral and PV cells underlie an inhibitory circuit poised to modulate the gain of olfactory bulb output.
Center for Neural Circuits and Behavior and Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA.
Hiroyuki K
HK
Kato
Shea N
SN
Gillet
Andrew J
AJ
Peters
Jeffry S
JS
Isaacson
Takaki
T
Komiyama
D000818:Animals; D000070585:Cadherin Related Proteins; D015820:Cadherins / Q000235:genetics; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000235:genetics / Q000378:metabolism; D066298:In Vitro Techniques; D007395:Interneurons / Q000378:metabolism*; D052139:Intracellular Calcium-Sensing Proteins / Q000235:genetics / Q000378:metabolism; D016014:Linear Models; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008564:Membrane Potentials / Q000235:genetics / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009415:Nerve Net / Q000502:physiology*; D009812:Odorants; D009830:Olfactory Bulb / Q000166:cytology*; D010320:Parvalbumins / Q000378:metabolism*; D045331:Photosystem I Protein Complex / Q000235:genetics / Q000378:metabolism; D037121:Plant Lectins / Q000235:genetics / Q000378:metabolism; D022661:RNA, Untranslated / Q000235:genetics; D018009:Receptors, Glycine / Q000235:genetics / Q000378:metabolism
D000070585:Cadherin Related Proteins; D015820:Cadherins; C110853:Gt(ROSA)26Sor non-coding RNA, mouse; D052139:Intracellular Calcium-Sensing Proteins; D008164:Luminescent Proteins; D010320:Parvalbumins; C504472:Pcdhgc3 protein, mouse; D045331:Photosystem I Protein Complex; D037121:Plant Lectins; D022661:RNA, Untranslated; D018009:Receptors, Glycine; C034981:tomato lectin; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2