Grouping and representation of odorant receptors in domains of the olfactory bulb sensory map

2002 ◽  
Vol 58 (3) ◽  
pp. 168 ◽  
Author(s):  
Hiroshi Nagao ◽  
Masahiro Yamaguchi ◽  
Yuji Takahash ◽  
Kensaku Mori
Keyword(s):  
Olfactory Bulb ◽  
Odorant Receptors ◽  
Sensory Map

Grouping of odorant receptors: odour maps in the mammalian olfactory bulb

2003 ◽  
Vol 31 (1) ◽  
pp. 134-136 ◽  
Author(s):  
K. Mori
Keyword(s):  
Olfactory Bulb ◽  
Spatial Organization ◽  
Odorant Receptor ◽  
Cellular Level ◽  
Odorant Receptors ◽  
Connectivity Pattern ◽  
Imaging Method ◽  
Molecular Feature ◽  
The One ◽  
Sensory Map

The olfactory system is unique in that the sensory input is in the form of molecular information carried in a vast variety of odorants. Nearly 1000 types of odorant receptors mediate the initial detection and discrimination of odorants at the molecular-feature level. The discrimination at the molecular level is converted into that at the cellular level (olfactory sensory neurons) by the one sensory neuron–one odorant receptor rule, and then into that at the neuronal circuit level in the olfactory bulb by the specific olfactory axon connectivity pattern. Individual glomeruli in the olfactory bulb represent a single odorant receptor, and the glomerular sheet at the olfactory bulb surface forms odorant receptor maps. This review focuses on the spatial organization of the glomerular sensory map in the olfactory bulb. The analysis using the optical imaging method suggests that odorant receptors having a common molecular-feature receptive site are grouped together and represented by glomeruli that are localized in topographically fixed domains in the olfactory bulb. The domain organization may be a structural unit for the spatial organization of the glomerular sensory map, and might relate to the olfactory submodality.

Odorant receptors instruct functional circuitry in the mouse olfactory bulb

Nature ◽  
2002 ◽  
Vol 419 (6904) ◽  
pp. 296-300 ◽  
Author(s):  
Leonardo Belluscio ◽  
Claudia Lodovichi ◽  
Paul Feinstein ◽  
Peter Mombaerts ◽  
Lawrence C. Katz
Keyword(s):  
Olfactory Bulb ◽  
Odorant Receptors ◽  
Functional Circuitry

Molecular Biology of Vertebrate Olfactory Receptors and Circuits

2021 ◽  
Author(s):  
Richard P. Tucker ◽  
Qizhi Gong
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Olfactory Bulb ◽  
Gene Family ◽  
Sensory Neuron ◽  
Sensory Neurons ◽  
Odorant Receptor ◽  
Vomeronasal Organ ◽  
Odorant Receptors ◽  
The Central Nervous System

Animals use their olfactory system for the procurement of food, the detection of danger, and the identification of potential mates. In vertebrates, the olfactory sensory neuron has a single apical dendrite that is exposed to the environment and a single basal axon that projects to the central nervous system (i.e., the olfactory bulb). The first odorant receptors to be discovered belong to an enormous gene family encoding G protein-coupled seven transmembrane domain proteins. Odorant binding to these classical odorant receptors initiates a GTP-dependent signaling cascade that uses cAMP as a second messenger. Subsequently, additional types of odorant receptors using different signaling pathways have been identified. While most olfactory sensory neurons are found in the olfactory sensory neuroepithelium, others are found in specialized olfactory subsystems. In rodents, the vomeronasal organ contains neurons that recognize pheromones, the septal organ recognizes odorant and mechanical stimuli, and the neurons of the Grüneberg ganglion are sensitive to cool temperatures and certain volatile alarm signals. Within the olfactory sensory neuroepithelium, each sensory neuron expresses a single odorant receptor gene out of the large gene family; the axons of sensory neurons expressing the same odorant receptor typically converge onto a pair of glomeruli at the periphery of the olfactory bulb. This results in the transformation of olfactory information into a spatially organized odortopic map in the olfactory bulb. The axons originating from the vomeronasal organ project to the accessory olfactory bulb, whereas the axons from neurons in the Grüneberg ganglion project to 10 specific glomeruli found in the caudal part of the olfactory bulb. Within a glomerulus, the axons originating from olfactory sensory neurons synapse on the dendrites of olfactory bulb neurons, including mitral and tufted cells. Mitral cells and tufted cells in turn project directly to higher brain centers (e.g., the piriform cortex and olfactory tubercle). The integration of olfactory information in the olfactory cortices and elsewhere in the central nervous system informs and directs animal behavior.

scholarly journals Role of Axonal Odorant Receptors in Olfactory Topography

2020 ◽  
Vol 15 ◽  
pp. 263310552092341
Author(s):  
Claudia Lodovichi
Keyword(s):  
Olfactory Bulb ◽  
Sensory Neurons ◽  
Axon Terminal ◽  
Internal Representation ◽  
Dual Role ◽  
Odorant Receptors ◽  
Topographic Map ◽  
And Function ◽  
Guidance Molecule

A unique feature in the organization of the olfactory system is the dual role of the odorant receptors: they detect odors in the nasal epithelium and they play an instructive role in the convergence of olfactory sensory neuron axons in specific loci, ie, glomeruli, in the olfactory bulb. The dual role is corroborated by the expression of the odorant receptors in 2 specific locations of the olfactory sensory neurons: the cilia that protrude in the nostril, where the odorant receptors interact with odors, and the axon terminal, a suitable location for a potential axon guidance molecule. The mechanism of activation and function of the odorant receptors expressed at the axon terminal remained unknown for almost 20 years. A recent study identified the first putative ligand of the axonal odorant receptors, phosphatidylethanolamine-binding protein1, a molecule expressed in the olfactory bulb. The distinctive mechanisms of activation of the odorant receptors expressed at the opposite locations in sensory neurons, by odors, at the cilia, and by molecules expressed in the olfactory bulb, at the axon terminal, explain the dual role of the odorant receptors and link the specificity of odor perception with its internal representation, in the topographic map.

Odorant Receptors in the Formation of the Olfactory Bulb Circuitry

Physiology ◽  
2012 ◽  
Vol 27 (4) ◽  
pp. 200-212 ◽  
Author(s):  
Claudia Lodovichi ◽  
Leonardo Belluscio
Keyword(s):  
Olfactory Bulb ◽  
Axon Guidance ◽  
Sensory Neurons ◽  
Odorant Receptors ◽  
Olfactory Sensory Neurons ◽  
Neural Connectivity ◽  
Axon Terminals ◽  
Primary Function

In mammals, smell is mediated by odorant receptors expressed by sensory neurons in the nose. These specialized receptors are found both on olfactory sensory neurons' cilia and axon terminals. Although the primary function of ciliary odorant receptors is to detect odorants, their axonal role remains unclear but is thought to involve axon guidance. This review discusses findings that show axonal odorant receptors are indeed functional and capable of modulating neural connectivity.

scholarly journals Immature olfactory sensory neurons provide behaviorally useful sensory input to the olfactory bulb

2021 ◽  
Author(s):  
Jane S Huang ◽  
Tenzin Kunkhyen ◽  
Beichen Liu ◽  
Ryan J Muggleton ◽  
Jonathan T Avon ◽  
...  
Keyword(s):  
Olfactory Bulb ◽  
Sensory Neurons ◽  
Sensory Input ◽  
Odorant Receptors ◽  
Projection Neurons ◽  
Olfactory Sensory Neurons ◽  
Odor Processing ◽  
Newborn Neurons ◽  
Behavioral Assays

Postnatal neurogenesis provides an opportunity to understand how newborn neurons functionally integrate into circuits to restore lost function. Newborn olfactory sensory neurons (OSNs) wire into highly organized olfactory bulb (OB) circuits throughout life, enabling lifelong plasticity and regeneration. Immature OSNs can form functional synapses capable of evoking firing in OB projection neurons. However, what contribution, if any, immature OSNs make to odor processing is unknown. Indeed, because immature OSNs can express multiple odorant receptors, any input that they do provide could degrade the odorant selectivity of input to OB glomeruli. Here, we used a combination of in vivo 2-photon calcium imaging, optogenetics, electrophysiology and behavioral assays to show that immature OSNs provide odor input to the OB, where they form monosynaptic connections with excitatory neurons. Importantly, immature OSNs responded as selectively to odorants as mature OSNs. Furthermore, mice successfully performed odor detection tasks using sensory input from immature OSNs alone. Immature OSNs responded more strongly to low odorant concentrations but their responses were less concentration dependent than those of mature OSNs, suggesting that immature and mature OSNs provide distinct odor input streams to each glomerulus. Together, our findings suggest that sensory input mediated by immature OSNs plays a previously unappreciated role in olfactory-guided behavior.

scholarly journals The olfactory bulb contributes to the adaptation of odor responses: the input-output transformation

2019 ◽  
Author(s):  
Douglas A. Storace ◽  
Lawrence B. Cohen
Keyword(s):  
Olfactory Bulb ◽  
Neural Mechanisms ◽  
Odorant Receptors ◽  
Nerve Terminals ◽  
Alternative Possibility ◽  
Perceptual Adaptation ◽  
Apical Dendrites ◽  
The Brain ◽  
Output Transformation ◽  
Stimulation Of

AbstractWhile humans and other animals exhibit adaptation to odorants, the neural mechanisms involved in this process are incompletely understood. One possibility is that it primarily occurs as a result of the interactions between odorants and odorant receptors expressed on the olfactory sensory neurons in the olfactory epithelium. In this scenario, adaptation would arise as a peripheral phenomenon transmitted into the brain. An alternative possibility is that adaptation occurs as a result of processing in the brain. Here we asked whether the olfactory bulb, the first stage of olfactory information processing in the brain, is involved in perceptual adaptation. Multicolor imaging was used to simultaneously measure the olfactory receptor nerve terminals (input) and mitral/tufted cell apical dendrites (output) that innervate the olfactory bulb glomerular layer. Repeated odor stimulation of the same concentration resulted in a decline in the output maps, while the input remained relatively stable. The results indicate that the mammalian olfactory bulb participates in olfactory adaptation.

Sign in / Sign up

Export Citation Format

Share Document