Abstract
Juxtaglomerular neurons represent one of the largest cellular populations in the mammalian olfactory bulb yet their role for signal processing remains unclear. We used two-photon imaging and electrophysiological recordings to clarify the in vivo properties of these cells and their functional organization in the juxtaglomerular space. Juxtaglomerular neurons coded for many perceptual characteristics of the olfactory stimulus such as (1) identity of the odorant, (2) odorant concentration, (3) odorant onset, and (4) offset. The odor-responsive neurons clustered within a narrow area surrounding the glomerulus with the same odorant specificity, with ~80% of responding cells located ≤20 μm from the glomerular border. This stereotypic spatial pattern of activated cells persisted at different odorant concentrations and was found for neurons both activated and inhibited by the odorant. Our data identify a principal glomerulus with a narrow shell of juxtaglomerular neurons as a basic odor coding unit in the glomerular layer and underline the important role of intraglomerular circuitry.
Highlights
The mammalian olfactory epithelium consists of a single layer of non-interacting olfactory receptor neurons (ORNs)
We show that juxtaglomerular neurons code for many perceptual characteristics of the olfactory stimulus including the identity of the odorant, odorant concentration as well as onset and offset of the odorant application
The spontaneous activity of juxtaglomerular neurons can be entrained by spontaneous firing of olfactory sensory neurons (Duchamp-Viret et al, 1999; Tan et al, 2010) and/or can result from intrinsic/synaptic activity within the local glomerular network (Hayar et al, 2004; Pignatelli et al, 2005; Liu and Shipley, 2008; De Saint Jan et al, 2009; Stakic et al, 2011)
Summary
The mammalian olfactory epithelium consists of a single layer of non-interacting olfactory receptor neurons (ORNs). Each ORN typically expresses only one type of olfactory receptor protein (Chess et al, 1994; Serizawa et al, 2000), which defines its odorant selectivity. Axons of thousands of ORNs expressing the same olfactory receptor protein converge onto a few (usually two) discrete glomeruli in one olfactory bulb (Vassar et al, 1994; Mombaerts et al, 1996). In the glomeruli the ORN axons synapse on the principal mitral/tufted neurons of the bulb and on local interneurons. The juxtaglomerular neurons have rich synaptic connections with each other They target both input [ORN axon terminals (Aroniadou-Anderjaska et al, 2000; McGann et al, 2005; Murphy et al, 2005)] and output (mitral/tufted) neurons of the bulb
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
