| First Author | Malvaut S | Year | 2017 |
| Journal | Curr Biol | Volume | 27 |
| Issue | 21 | Pages | 3315-3329.e6 |
| PubMed ID | 29107547 | Mgi Jnum | J:272632 |
| Mgi Id | MGI:6285103 | Doi | 10.1016/j.cub.2017.09.058 |
| Citation | Malvaut S, et al. (2017) CaMKIIalpha Expression Defines Two Functionally Distinct Populations of Granule Cells Involved in Different Types of Odor Behavior. Curr Biol 27(21):3315-3329.e6 |
| abstractText | Granule cells (GCs) in the olfactory bulb (OB) play an important role in odor information processing. Although they have been classified into various neurochemical subtypes, the functional roles of these subtypes remain unknown. We used in vivo two-photon Ca(2+) imaging combined with cell-type-specific identification of GCs in the mouse OB to examine whether functionally distinct GC subtypes exist in the bulbar network. We showed that half of GCs express Ca(2+)/calmodulin-dependent protein kinase IIalpha (CaMKIIalpha(+)) and that these neurons are preferentially activated by olfactory stimulation. The higher activity of CaMKIIalpha(+) neurons is due to the weaker inhibitory input that they receive compared to their CaMKIIalpha-immunonegative (CaMKIIalpha(-)) counterparts. In line with these functional data, immunohistochemical analyses showed that 75%-90% of GCs expressing the immediate early gene cFos are CaMKIIalpha(+) in naive animals and in mice that have been exposed to a novel odor and go/no-go operant conditioning, or that have been subjected to long-term associative memory and spontaneous habituation/dishabituation odor discrimination tasks. On the other hand, a perceptual learning task resulted in increased activation of CaMKIIalpha(-) cells. Pharmacogenetic inhibition of CaMKIIalpha(+) GCs revealed that this subtype is involved in habituation/dishabituation and go/no-go odor discrimination, but not in perceptual learning. In contrast, pharmacogenetic inhibition of GCs in a subtype-independent manner affected perceptual learning. Our results indicate that functionally distinct populations of GCs exist in the OB and that they play distinct roles during different odor tasks. |
