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Weiss J, Zufall F. Presynaptic GABA B receptors inhibit vomeronasal nerve transmission to accessory olfactory bulb mitral cells. Front Cell Neurosci 2023; 17:1302955. [PMID: 38130867 PMCID: PMC10733964 DOI: 10.3389/fncel.2023.1302955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 11/08/2023] [Indexed: 12/23/2023] Open
Abstract
Vomeronasal sensory neurons (VSNs) recognize pheromonal and kairomonal semiochemicals in the lumen of the vomeronasal organ. VSNs send their axons along the vomeronasal nerve (VN) into multiple glomeruli of the accessory olfactory bulb (AOB) and form glutamatergic synapses with apical dendrites of mitral cells, the projection neurons of the AOB. Juxtaglomerular interneurons release the inhibitory neurotransmitter γ-aminobutyric acid (GABA). Besides ionotropic GABA receptors, the metabotropic GABAB receptor has been shown to modulate synaptic transmission in the main olfactory system. Here we show that GABAB receptors are expressed in the AOB and are primarily located at VN terminals. Electrical stimulation of the VN provokes calcium elevations in VSN nerve terminals, and activation of GABAB receptors by the agonist baclofen abolishes calcium influx in AOB slice preparations. Patch clamp recordings reveal that synaptic transmission from the VN to mitral cells can be completely suppressed by activation of GABAB receptors. A potent GABAB receptor antagonist, CGP 52432, reversed the baclofen-induced effects. These results indicate that modulation of VSNs via activation of GABAB receptors affects calcium influx and glutamate release at presynaptic terminals and likely balances synaptic transmission at the first synapse of the accessory olfactory system.
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Affiliation(s)
- Jan Weiss
- Center for Integrative Physiology and Molecular Medicine (CIPMM), Saarland University, Homburg, Germany
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Huang JS, Kunkhyen T, Rangel AN, Brechbill TR, Gregory JD, Winson-Bushby ED, Liu B, Avon JT, Muggleton RJ, Cheetham CEJ. Immature olfactory sensory neurons provide behaviourally relevant sensory input to the olfactory bulb. Nat Commun 2022; 13:6194. [PMID: 36261441 PMCID: PMC9582225 DOI: 10.1038/s41467-022-33967-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 10/07/2022] [Indexed: 01/12/2023] Open
Abstract
Postnatal neurogenesis provides an opportunity to understand how newborn neurons integrate into circuits to restore function. Newborn olfactory sensory neurons (OSNs) wire into highly organized olfactory bulb (OB) circuits throughout life, enabling lifelong plasticity and regeneration. Immature OSNs form functional synapses capable of evoking firing in OB projection neurons but what contribution, if any, they make to odor processing is unknown. Here, we show that immature OSNs provide odor input to the mouse OB, where they form monosynaptic connections with excitatory neurons. Importantly, immature OSNs respond as selectively to odorants as mature OSNs and exhibit graded responses across a wider range of odorant concentrations than mature OSNs, suggesting that immature and mature OSNs provide distinct odor input streams. Furthermore, mice can successfully perform odor detection and discrimination tasks using sensory input from immature OSNs alone. Together, our findings suggest that immature OSNs play a previously unappreciated role in olfactory-guided behavior.
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Affiliation(s)
- Jane S Huang
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop St, Pittsburgh, PA, 15232, USA
| | - Tenzin Kunkhyen
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop St, Pittsburgh, PA, 15232, USA
| | - Alexander N Rangel
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop St, Pittsburgh, PA, 15232, USA
| | - Taryn R Brechbill
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop St, Pittsburgh, PA, 15232, USA
| | - Jordan D Gregory
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop St, Pittsburgh, PA, 15232, USA
| | - Emily D Winson-Bushby
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop St, Pittsburgh, PA, 15232, USA
| | - Beichen Liu
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop St, Pittsburgh, PA, 15232, USA
- Department of Biological Sciences, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA, 15213, USA
| | - Jonathan T Avon
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop St, Pittsburgh, PA, 15232, USA
| | - Ryan J Muggleton
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop St, Pittsburgh, PA, 15232, USA
- Department of Biological Sciences, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA, 15213, USA
| | - Claire E J Cheetham
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop St, Pittsburgh, PA, 15232, USA.
- Department of Biological Sciences, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA, 15213, USA.
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Lankford CK, Laird JG, Inamdar SM, Baker SA. A Comparison of the Primary Sensory Neurons Used in Olfaction and Vision. Front Cell Neurosci 2020; 14:595523. [PMID: 33250719 PMCID: PMC7676898 DOI: 10.3389/fncel.2020.595523] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Accepted: 10/06/2020] [Indexed: 12/18/2022] Open
Abstract
Vision, hearing, smell, taste, and touch are the tools used to perceive and navigate the world. They enable us to obtain essential resources such as food and highly desired resources such as mates. Thanks to the investments in biomedical research the molecular unpinning’s of human sensation are rivaled only by our knowledge of sensation in the laboratory mouse. Humans rely heavily on vision whereas mice use smell as their dominant sense. Both modalities have many features in common, starting with signal detection by highly specialized primary sensory neurons—rod and cone photoreceptors (PR) for vision, and olfactory sensory neurons (OSN) for the smell. In this chapter, we provide an overview of how these two types of primary sensory neurons operate while highlighting the similarities and distinctions.
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Affiliation(s)
- Colten K Lankford
- Department of Biochemistry, University of Iowa, Iowa City, IA, United States
| | - Joseph G Laird
- Department of Biochemistry, University of Iowa, Iowa City, IA, United States
| | - Shivangi M Inamdar
- Department of Biochemistry, University of Iowa, Iowa City, IA, United States
| | - Sheila A Baker
- Department of Biochemistry, University of Iowa, Iowa City, IA, United States.,Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, United States
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Pyrski M, Tusty M, Eckstein E, Oboti L, Rodriguez-Gil DJ, Greer CA, Zufall F. P/Q Type Calcium Channel Cav2.1 Defines a Unique Subset of Glomeruli in the Mouse Olfactory Bulb. Front Cell Neurosci 2018; 12:295. [PMID: 30233329 PMCID: PMC6131590 DOI: 10.3389/fncel.2018.00295] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 08/16/2018] [Indexed: 11/24/2022] Open
Abstract
Voltage-gated calcium (Cav) channels are a prerequisite for signal transmission at the first olfactory sensory neuron (OSN) synapse within the glomeruli of the main olfactory bulb (MOB). We showed previously that the N-type Cav channel subunit Cav2.2 is present in the vast majority of glomeruli and plays a central role in presynaptic transmitter release. Here, we identify a distinct subset of glomeruli in the MOB of adult mice that is characterized by expression of the P/Q-type channel subunit Cav2.1. Immunolocalization shows that Cav2.1+ glomeruli reside predominantly in the medial and dorsal MOB, and in the vicinity of the necklace glomerular region close to the accessory olfactory bulb. Few glomeruli are detected on the ventral and lateral MOB. Cav2.1 labeling in glomeruli colocalizes with the presynaptic marker vGlut2 in the axon terminals of OSNs. Electron microscopy shows that Cav2.1+ presynaptic boutons establish characteristic asymmetrical synapses with the dendrites of second-order neurons in the glomerular neuropil. Cav2.1+ glomeruli receive axonal input from OSNs that express molecules of canonical OSNs: olfactory marker protein, the ion channel Cnga2, and the phosphodiesterase Pde4a. In the main olfactory epithelium, Cav2.1 labels a distinct subpopulation of OSNs whose distribution mirrors the topography of the MOB glomeruli, that shows the same molecular signature, and is already present at birth. Together, these experiments identify a unique Cav2.1+ multiglomerular domain in the MOB that may form a previously unrecognized olfactory subsystem distinct from other groups of necklace glomeruli that rely on cGMP signaling mechanisms.
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Affiliation(s)
- Martina Pyrski
- Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
| | - Mahbuba Tusty
- Department of Neuroscience and Department of Neurosurgery, School of Medicine, Yale University, New Haven, CT, United States
| | - Eugenia Eckstein
- Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
| | - Livio Oboti
- Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
| | - Diego J. Rodriguez-Gil
- Department of Neuroscience and Department of Neurosurgery, School of Medicine, Yale University, New Haven, CT, United States
| | - Charles A. Greer
- Department of Neuroscience and Department of Neurosurgery, School of Medicine, Yale University, New Haven, CT, United States
| | - Frank Zufall
- Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
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Genovese F, Thews M, Möhrlen F, Frings S. Properties of an optogenetic model for olfactory stimulation. J Physiol 2016; 594:3501-16. [PMID: 26857095 DOI: 10.1113/jp271853] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Accepted: 01/22/2016] [Indexed: 12/21/2022] Open
Abstract
KEY POINTS In olfactory research it is difficult to deliver stimuli with defined intensity and duration to olfactory sensory neurons. Expression of channelrhodopsin 2 (ChR2) in olfactory sensory neurons provides a means to activate these neurons with light flashes. Appropriate mouse models are available. The present study explores the suitability of an established olfactory marker protein (OMP)/ChR2-yellow fluorescent protein (YFP) mouse model for ex vivo experimentation. Expression of ChR2 in sensory neurons of the main olfactory epithelium, the septal organ and vomeronasal organ is characterized. Expression pattern of ChR2 in olfactory receptor neurons and the properties of light responses indicate that light stimulation does not impact on signal transduction in the chemosensory cilia. Light-induced electro-olfactograms are characterized with light flashes of different intensities, durations and frequencies. The impact of light-induced afferent stimulation on the olfactory bulb is examined with respect to response amplitude, polarity and low-pass filtering. ABSTRACT For the examination of sensory processing, it is helpful to deliver stimuli in precisely defined temporal and spatial patterns with accurate control of stimulus intensity. This is challenging in experiments with the mammalian olfactory system because airborne odorants have to be transported into the intricate sensory structures of the nose and must dissolve in mucus to be detected by sensory neurons. Defined and reproducible activity can be generated in olfactory sensory neurons that express the light-gated ion channel channelrhodopsin 2 (ChR2). The neurons can be stimulated by light flashes in a controlled fashion by this optogenetic approach. Here we examined the application of an olfactory marker protein (OMP)/ChR2-yellow fluorescent protein (YFP) model for ex vivo exploration of the olfactory epithelium and the olfactory bulb of the mouse. We studied the expression patterns of ChR2 in the main olfactory system, the vomeronasal system, and the septal organ, and we found that ChR2 is absent from the sensory cilia of olfactory sensory neurons. In the olfactory epithelium, we characterized light-induced electro-olfactograms with respect to peripheral encoding of stimulus intensity, stimulus duration and stimulus frequency. In acute slices of the olfactory bulb, we identified specific aspects of the ChR2-induced input signal, concerning its dynamic range, its low-pass filter property and its response to prolonged stimulation. Our study describes the performance of the OMP/ChR2-YFP model for ex vivo experimentation on the peripheral olfactory system and documents its versatility and its limitations for olfactory research.
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Affiliation(s)
- Federica Genovese
- Department of Animal Molecular Physiology, Centre of Organismal Studies, Im Neuenheimer Feld 504, Heidelberg University, Heidelberg, Germany
| | - Marion Thews
- Department of Animal Molecular Physiology, Centre of Organismal Studies, Im Neuenheimer Feld 504, Heidelberg University, Heidelberg, Germany
| | - Frank Möhrlen
- Department of Animal Molecular Physiology, Centre of Organismal Studies, Im Neuenheimer Feld 504, Heidelberg University, Heidelberg, Germany
| | - Stephan Frings
- Department of Animal Molecular Physiology, Centre of Organismal Studies, Im Neuenheimer Feld 504, Heidelberg University, Heidelberg, Germany
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