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Raji JI, Konopka JK, Potter CJ. A spatial map of antennal-expressed ionotropic receptors in the malaria mosquito. Cell Rep 2023; 42:112101. [PMID: 36773296 PMCID: PMC10412736 DOI: 10.1016/j.celrep.2023.112101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 12/22/2022] [Accepted: 01/26/2023] [Indexed: 02/12/2023] Open
Abstract
The mosquito's antenna represents its main olfactory appendage for detecting volatile chemical cues from the environment. Whole-mount fluorescence in situ hybridization of ionotropic receptors (IRs) expressed in the antennae reveals that the antenna might be divisible into proximal and distal functional domains. The number of IR-positive cells appear stereotyped within each antennal segment (flagellomere). Highly expressed odor-tuning IRs exhibit distinct co-localization patterns with the IR coreceptors Ir8a, Ir25a, and Ir76b that might predict their functional properties. Genetic knockin and in vivo functional imaging of IR41c-expressing neurons indicate both odor-induced activation and inhibition in response to select amine compounds. Targeted mutagenesis of IR41c does not abolish behavioral responses to the amine compounds. Our study provides a comprehensive map of IR-expressing neurons in the main olfactory appendage of mosquitoes. These findings show organizing principles of Anopheles IR-expressing neurons, which might underlie their functional contribution to the detection of behaviorally relevant odors.
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Affiliation(s)
- Joshua I Raji
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Joanna K Konopka
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Christopher J Potter
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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2
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Han J, Kang M, Jeong J, Cho I, Yu J, Yoon K, Park I, Choi Y. Artificial Olfactory Neuron for an In-Sensor Neuromorphic Nose. Adv Sci (Weinh) 2022; 9:e2106017. [PMID: 35426489 PMCID: PMC9218653 DOI: 10.1002/advs.202106017] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 03/10/2022] [Indexed: 06/02/2023]
Abstract
A neuromorphic module of an electronic nose (E-nose) is demonstrated by hybridizing a chemoresistive gas sensor made of a semiconductor metal oxide (SMO) and a single transistor neuron (1T-neuron) made of a metal-oxide-semiconductor field-effect transistor (MOSFET). By mimicking a biological olfactory neuron, it simultaneously detects a gas and encoded spike signals for in-sensor neuromorphic functioning. It identifies an odor source by analyzing the complicated mixed signals using a spiking neural network (SNN). The proposed E-nose does not require conversion circuits, which are essential for processing the sensory signals between the sensor array and processors in the conventional bulky E-nose. In addition, they do not have to include a central processing unit (CPU) and memory, which are required for von Neumann computing. The spike transmission of the biological olfactory system, which is known to be the main factor for reducing power consumption, is realized with the SNN for power savings compared to the conventional E-nose with a deep neural network (DNN). Therefore, the proposed neuromorphic E-nose is promising for application to Internet of Things (IoT), which demands a highly scalable and energy-efficient system. As a practical example, it is employed as an electronic sommelier by classifying different types of wines.
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Affiliation(s)
- Joon‐Kyu Han
- School of Electrical EngineeringKorea Advanced Institute of Science and Technology (KAIST)291 Daehak‐ro, Yuseong‐guDaejeon34141Republic of Korea
| | - Mingu Kang
- Department of Mechanical EngineeringKorea Advanced Institute of Science and Technology (KAIST)291 Daehak‐ro, Yuseong‐guDaejeon34141Republic of Korea
| | - Jaeseok Jeong
- Department of Mechanical EngineeringKorea Advanced Institute of Science and Technology (KAIST)291 Daehak‐ro, Yuseong‐guDaejeon34141Republic of Korea
| | - Incheol Cho
- Department of Mechanical EngineeringKorea Advanced Institute of Science and Technology (KAIST)291 Daehak‐ro, Yuseong‐guDaejeon34141Republic of Korea
| | - Ji‐Man Yu
- School of Electrical EngineeringKorea Advanced Institute of Science and Technology (KAIST)291 Daehak‐ro, Yuseong‐guDaejeon34141Republic of Korea
| | - Kuk‐Jin Yoon
- Department of Mechanical EngineeringKorea Advanced Institute of Science and Technology (KAIST)291 Daehak‐ro, Yuseong‐guDaejeon34141Republic of Korea
| | - Inkyu Park
- Department of Mechanical EngineeringKorea Advanced Institute of Science and Technology (KAIST)291 Daehak‐ro, Yuseong‐guDaejeon34141Republic of Korea
| | - Yang‐Kyu Choi
- School of Electrical EngineeringKorea Advanced Institute of Science and Technology (KAIST)291 Daehak‐ro, Yuseong‐guDaejeon34141Republic of Korea
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Zhang AJ, Lee ACY, Chu H, Chan JFW, Fan Z, Li C, Liu F, Chen Y, Yuan S, Poon VKM, Chan CCS, Cai JP, Wu KLK, Sridhar S, Chan YS, Yuen KY. Severe Acute Respiratory Syndrome Coronavirus 2 Infects and Damages the Mature and Immature Olfactory Sensory Neurons of Hamsters. Clin Infect Dis 2021; 73:e503-e512. [PMID: 32667973 PMCID: PMC7454453 DOI: 10.1093/cid/ciaa995] [Citation(s) in RCA: 82] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 07/13/2020] [Indexed: 01/08/2023] Open
Abstract
Background Coronavirus Disease 2019 (COVID-19) is primarily an acute respiratory tract infection. Distinctively, a substantial proportion of COVID-19 patients develop olfactory dysfunction of uncertain underlying mechanism which can be severe and prolonged. The roles of inflammatory obstruction of the olfactory clefts leading to conductive impairment, inflammatory cytokines affecting olfactory neuronal function, destruction of olfactory neurons or their supporting cells, and direct invasion of olfactory bulbs, in causing olfactory dysfunction are uncertain. Methods In this study, we investigated the location for the pathogenesis of SARS-CoV-2 from the olfactory epithelium (OE) of the nasopharynx to the olfactory bulb of golden Syrian hamsters. Results After intranasal inoculation with SARS-CoV-2, inflammatory cell infiltration and proinflammatory cytokine/chemokine responses were detected in the nasal turbinate tissues which peaked between 2 to 4 days post-infection with the highest viral load detected at day 2 post-infection. Besides the nasopharyngeal pseudo-columnar ciliated respiratory epithelial cells, SARS-CoV-2 viral antigens were also detected in the more superficial mature olfactory sensory neurons labeled by olfactory marker protein (OMP), the less mature olfactory neurons labelled by Tuj1 at more basal position, and the sustentacular cells which provide metabolic and physical support for the olfactory neurons, resulting in apoptosis and severe destruction of the OE. During the whole course of infection, SARS-CoV-2 viral antigens were not detected in the olfactory bulb. Conclusions Besides acute inflammation at OE, infection of mature and immature olfactory neurons, and the supporting sustentacular cells by SARS-CoV-2 may contribute to the unique olfactory dysfunction of COVID-19 which is not reported with SARS-CoV.
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Affiliation(s)
- Anna Jinxia Zhang
- State Key Laboratory of Emerging Infectious Diseases, University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Department of Microbiology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Carol Yu Centre for Infection, University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - Andrew Chak-Yiu Lee
- Department of Microbiology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - Hin Chu
- State Key Laboratory of Emerging Infectious Diseases, University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Department of Microbiology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Carol Yu Centre for Infection, University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - Jasper Fuk-Woo Chan
- State Key Laboratory of Emerging Infectious Diseases, University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Department of Microbiology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Carol Yu Centre for Infection, University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Department of Microbiology, Queen Mary Hospital, Pokfulam, Hong Kong Special Administrative Region, China
| | - Zhimeng Fan
- Department of Microbiology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - Can Li
- Department of Microbiology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - Feifei Liu
- Department of Microbiology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - Yanxia Chen
- Department of Microbiology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - Shuofeng Yuan
- State Key Laboratory of Emerging Infectious Diseases, University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Department of Microbiology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Carol Yu Centre for Infection, University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - Vincent Kwok-Man Poon
- Department of Microbiology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - Chris Chung-Sing Chan
- Department of Microbiology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - Jian-Piao Cai
- Department of Microbiology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - Kenneth Lap-Kei Wu
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong Special Administrative Region, China.,State Key Laboratory of Brain and Cognitive Sciences, University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - Siddharth Sridhar
- State Key Laboratory of Emerging Infectious Diseases, University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Department of Microbiology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Carol Yu Centre for Infection, University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Department of Microbiology, Queen Mary Hospital, Pokfulam, Hong Kong Special Administrative Region, China
| | - Ying-Shing Chan
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong Special Administrative Region, China.,State Key Laboratory of Brain and Cognitive Sciences, University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - Kwok-Yung Yuen
- State Key Laboratory of Emerging Infectious Diseases, University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Department of Microbiology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Carol Yu Centre for Infection, University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Department of Microbiology, Queen Mary Hospital, Pokfulam, Hong Kong Special Administrative Region, China
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Conchou L, Lucas P, Deisig N, Demondion E, Renou M. Effects of Multi-Component Backgrounds of Volatile Plant Compounds on Moth Pheromone Perception. Insects 2021; 12:insects12050409. [PMID: 34062868 PMCID: PMC8147264 DOI: 10.3390/insects12050409] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 04/26/2021] [Accepted: 04/30/2021] [Indexed: 12/02/2022]
Abstract
Simple Summary It is well acknowledged that some of the volatile plant compounds (VPC) naturally present in insect natural habitats alter the perception of their own pheromone when presented individually as a background to pheromone. However, the effects of mixing VPCs as they appear to insects in natural olfactory landscapes are poorly understood. We measured the activity of brain neurons and neurons that detect a sex pheromone component in a moth antenna, while exposed to simple or composite backgrounds of VPCs representative of the odorant variety encountered by this moth. Maps of activities were built using calcium imaging to visualize which brain areas were most affected by VPCs. In the antenna, we observed differences in VPC capacity to elicit firing response that cannot be explained by differences in stimulus intensities because we adjusted concentrations according to volatility. The neuronal network, which reformats the input from antenna neurons in the brain, did not improve pheromone salience. We postulate that moth olfactory system evolved to increase sensitivity and encode fast changes of concentration at some cost for signal extraction. Comparing blends to single compounds indicated that a blend shows the activity of its most active component, VPC salience seems more important than background complexity. Abstract The volatile plant compounds (VPC) alter pheromone perception by insects but mixture effects inside insect olfactory landscapes are poorly understood. We measured the activity of receptor neurons tuned to Z7-12Ac (Z7-ORN), a pheromone component, in the antenna and central neurons in male Agrotis ipsilon while exposed to simple or composite backgrounds of a panel of VPCs representative of the odorant variety encountered by a moth. Maps of activities were built using calcium imaging to visualize which areas in antennal lobes (AL) were affected by VPCs. We compared the VPC activity and their impact as backgrounds at antenna and AL levels, individually or in blends. At periphery, VPCs showed differences in their capacity to elicit Z7-ORN firing response that cannot be explained by differences in stimulus intensities because we adjusted concentrations according to vapor pressures. The AL neuronal network, which reformats the ORN input, did not improve pheromone salience. We postulate that the AL network evolved to increase sensitivity and to encode for fast changes of pheromone at some cost for signal extraction. Comparing blends to single compounds indicated that a blend shows the activity of its most active component. VPC salience seems to be more important than background complexity.
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Chan MH, Chen HH, Lo YC, Wu SN. Effectiveness in the Block by Honokiol, a Dimerized Allylphenol from Magnolia Officinalis, of Hyperpolarization-Activated Cation Current and Delayed-Rectifier K + Current. Int J Mol Sci 2020; 21:ijms21124260. [PMID: 32549398 PMCID: PMC7352210 DOI: 10.3390/ijms21124260] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 06/03/2020] [Accepted: 06/09/2020] [Indexed: 12/22/2022] Open
Abstract
Background: Honokiol (HNK), a dimer of allylphenol obtained from the bark of Magnolia officinalis was demonstrated to exert an array of biological actions in different excitable cell types. However, whether or how this compound can lead to any perturbations on surface-membrane ionic currents remains largely unknown. Methods: We used the patch clamp method and found that addition of HNK effectively depressed the density of macroscopic hyperpolarization-activated cation currents (Ih) in pituitary GH3 cells in a concentration-, time- and voltage-dependent manner. By the use of a two-step voltage protocol, the presence of HNK (10 μM) shifted the steady-state activation curve of Ih density along the voltage axis to a more negative potential by approximately 11 mV, together with no noteworthy modification in the gating charge of the current. Results: The voltage-dependent hysteresis of Ih density elicited by long-lasting triangular ramp pulse was attenuated by the presence of HNK. The HNK addition also diminished the magnitude of deactivating Ih density elicited by ramp-up depolarization with varying durations. The effective half-maximal concentration (IC50) value needed to inhibit the density of Ih or delayed rectifier K+ current identified in GH3 cells was estimated to be 2.1 or 6.8 μM, respectively. In cell-attached current recordings, HNK decreased the frequency of spontaneous action currents. In Rolf B1.T olfactory sensory neurons, HNK was also observed to decrease Ih density in a concentration-dependent manner. Conclusions: The present study highlights the evidence revealing that HNK has the propensity to perturb these ionic currents and that the hyperpolarization-activated cyclic nucleotide-gated (HCN) channel is proposed to be a potential target for the in vivo actions of HNK and its structurally similar compounds.
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Affiliation(s)
- Ming-Huan Chan
- Institute of Neuroscience, National Chengchi University, Taipei 11605, Taiwan; (M.-H.C.); (H.-H.C.)
| | - Hwei-Hsien Chen
- Institute of Neuroscience, National Chengchi University, Taipei 11605, Taiwan; (M.-H.C.); (H.-H.C.)
- Center of Neuropsychiatric Research, National Health Research Institutes, Miaoli County 35053, Taiwan
| | - Yi-Ching Lo
- Department of Pharmacology, Kaohsiung Medical University, Kaohsiung 80708, Taiwan;
| | - Sheng-Nan Wu
- Department of Physiology, National Cheng Kung University Medical College, Tainan 70101, Taiwan
- Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan 70101, Taiwan
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung 40402, Taiwan
- Correspondence:
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Chang WT, Gao ZH, Li SW, Liu PY, Lo YC, Wu SN. Characterization in Dual Activation by Oxaliplatin, a Platinum-Based Chemotherapeutic Agent of Hyperpolarization-Activated Cation and Electroporation-Induced Currents. Int J Mol Sci 2020; 21:ijms21020396. [PMID: 31936301 PMCID: PMC7014111 DOI: 10.3390/ijms21020396] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 12/30/2019] [Accepted: 01/04/2020] [Indexed: 12/17/2022] Open
Abstract
Oxaliplatin (OXAL) is regarded as a platinum-based anti-neoplastic agent. However, its perturbations on membrane ionic currents in neurons and neuroendocrine or endocrine cells are largely unclear, though peripheral neuropathy has been noted during its long-term administration. In this study, we investigated how the presence of OXAL and other related compounds can interact with two types of inward currents; namely, hyperpolarization-activated cation current (Ih) and membrane electroporation-induced current (IMEP). OXAL increased the amplitude or activation rate constant of Ih in a concentration-dependent manner with effective EC50 or KD values of 3.2 or 6.4 μM, respectively, in pituitary GH3 cells. The stimulation by this agent of Ih could be attenuated by subsequent addition of ivabradine, protopine, or dexmedetomidine. Cell exposure to OXAL (3 μM) resulted in an approximately 11 mV rightward shift in Ih activation along the voltage axis with minimal changes in the gating charge of the curve. The exposure to OXAL also effected an elevation in area of the voltage-dependent hysteresis elicited by long-lasting triangular ramp. Additionally, its application resulted in an increase in the amplitude of IMEP elicited by large hyperpolarization in GH3 cells with an EC50 value of 1.3 μM. However, in the continued presence of OXAL, further addition of ivabradine, protopine, or dexmedetomidine always resulted in failure to attenuate the OXAL-induced increase of IMEP amplitude effectively. Averaged current-voltage relation of membrane electroporation-induced current (IMEP) was altered in the presence of OXAL. In pituitary R1220 cells, OXAL-stimulated Ih remained effective. In Rolf B1.T olfactory sensory neurons, this agent was also observed to increase IMEP in a concentration-dependent manner. In light of the findings from this study, OXAL-mediated increases of Ih and IMEP may coincide and then synergistically act to increase the amplitude of inward currents, raising the membrane excitability of electrically excitable cells, if similar in vivo findings occur.
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Affiliation(s)
- Wei-Ting Chang
- Division of Cardiovascular Medicine, Chi-Mei Medical Center, Tainan 71004, Taiwan;
- Department of Biotechnology, Southern Taiwan University of Science and Technology, Tainan 71004, Taiwan
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan;
| | - Zi-Han Gao
- Department of Physiology, National Cheng Kung University Medical College, Tainan 70101, Taiwan; (Z.-H.G.); (S.-W.L.)
| | - Shih-Wei Li
- Department of Physiology, National Cheng Kung University Medical College, Tainan 70101, Taiwan; (Z.-H.G.); (S.-W.L.)
| | - Ping-Yen Liu
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan;
- Division of Cardiovascular Medicine, Internal Medicine, College of Medicine, National Cheng Kung University Hospital, Tainan 70401, Taiwan
| | - Yi-Ching Lo
- Department of Pharmacology, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan;
| | - Sheng-Nan Wu
- Department of Physiology, National Cheng Kung University Medical College, Tainan 70101, Taiwan; (Z.-H.G.); (S.-W.L.)
- Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan 70101, Taiwan
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung 40402, Taiwan
- Correspondence:
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Yu Y, Boyer NP, Zhang C. Three structurally similar odorants trigger distinct signaling pathways in a mouse olfactory neuron. Neuroscience 2014; 275:194-210. [PMID: 24929067 DOI: 10.1016/j.neuroscience.2014.05.063] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Revised: 04/08/2014] [Accepted: 05/22/2014] [Indexed: 12/20/2022]
Abstract
In the mammalian olfactory system, one olfactory sensory neuron (OSN) expresses a single olfactory receptor gene. By calcium imaging of individual OSNs in intact mouse olfactory turbinates, we observed that a subset of OSNs (Ho-OSNs) located in the most ventral olfactory receptor zone can mediate distinct signaling pathways when activated by structurally similar ligands. Calcium imaging showed that Ho-OSNs were highly sensitive to 2-heptanone, heptaldehyde and cis-4-heptenal. 2-heptanone-evoked intracellular calcium elevation was mediated by cAMP signaling while heptaldehyde triggered the diacylglycerol pathway. An increase of intracellular calcium evoked by cis-4-heptenal was due to a combination of activation mediated by the adenylate cyclase pathway and suppression generated by phospholipase C signaling. Pharmacological studies demonstrated that novel mechanisms were involved in the phospholipase C-mediated intracellular calcium changes. Binary-mixture studies and cross-adaptation data indicate that three odorants acted on the same olfactory receptor. The feature that an olfactory receptor mediates multiple signaling pathways was specific for Ho-OSNs and not established in another population of OSNs characterized. Our study suggests that distinct signaling pathways triggered by ligand-induced conformational changes of an olfactory receptor constitute a complex information process mechanism in olfactory transduction. This study has important implications beyond olfaction in that it provides insights of plasticity and complexity of G-protein-coupled receptor activation and signal transduction.
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Affiliation(s)
- Y Yu
- Department of Biological and Chemical Sciences, Illinois Institute of Technology, 3101 S. Dearborn Street, Chicago, IL 60616, USA
| | - N P Boyer
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC 29425, USA; Department of Neurosciences, Medical University of South Carolina, Charleston, SC 29425, USA
| | - C Zhang
- Department of Biological and Chemical Sciences, Illinois Institute of Technology, 3101 S. Dearborn Street, Chicago, IL 60616, USA.
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Abstract
A recent paper by the Dahankuar laboratory suggested that single Drosophila sugar receptors proteins accurately mediate sugar detection when ectopically expressed in olfactory neurons of the antenna. These findings contra-dict numerous previously published electrophysiological and behavioral investigations, which all point towards heteromultimeric sugar taste receptors. Here, I provide some explanation why this "pseudo-heterologous" expression system may have led to this misleading conclusion.
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Affiliation(s)
- Hubert Amrein
- Department of Molecular and Cellular Medicine; Texas A&M Health Science Center; College Station, TX USA
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Abstract
Phantosmia, the perception of an odor when there are no odorants in the environment, can be a very debilitating symptom. In the 1960s, Zilstorff reported olfactory distortions could be treated by the topical application of a cocaine solution to the olfactory epithelium. In evaluating this treatment, we observed no long-term benefit using cocaine on 6 patients with phantosmia. Based on our observations, the patient's olfactory ability was not a determining factor in the initiation or quality of their phantosmia. Following topical cocainization, we observed a remarkable delay of hours to days in the return of olfactory ability, and when cocaine was applied to only 1 nostril, there was a decreased olfactory ability on the noncocainized side. These results may suggest the possibility that phantosmia is related to a central processing problem.
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Affiliation(s)
- Donald A Leopold
- Department of Surgery ENT division, University of Vermont, Burlington, VT 05401, USA.
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Torayama I, Ishihara T, Katsura I. Caenorhabditis elegans integrates the signals of butanone and food to enhance chemotaxis to butanone. J Neurosci 2007; 27:741-50. [PMID: 17251413 PMCID: PMC6672901 DOI: 10.1523/jneurosci.4312-06.2007] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2006] [Revised: 12/04/2006] [Accepted: 12/05/2006] [Indexed: 11/21/2022] Open
Abstract
Behavioral plasticity induced by the integration of two sensory signals, such as associative learning, is an important issue in neuroscience, but its evolutionary origin and diversity have not been explored sufficiently. We report here a new type of such behavioral plasticity, which we call butanone enhancement, in Caenorhabditis elegans adult hermaphrodites: C. elegans specifically enhances chemotaxis to butanone by preexposure to butanone and food. Mutant analysis revealed that this plasticity requires the AWC(ON) olfactory neuron, whose fate is known to be determined by the NSY-1/ASK1 MAPKKK (mitogen-activated protein kinase kinase kinase) cascade as well as the DAF-11 and ODR-1 guanylyl cyclases. These proteins also control many aspects of olfactory sensation/plasticity in AWC neurons and seem to provide appropriate cellular conditions for butanone enhancement in the AWC(ON) neuron. Butanone enhancement also required the functions of Bardet-Biedl syndrome genes in the AWC(ON) neuron but not other genes that control ciliary transport. Furthermore, preexposure to butanone and the odor of food was enough for the enhancement of butanone chemotaxis. These results suggest that the AWC(ON) olfactory neuron may conduct a behavioral plasticity resembling associative learning and that the functions of Bardet-Biedl syndrome genes in sensory cilia may play an important role in this plasticity.
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Affiliation(s)
- Ichiro Torayama
- Structural Biology Center, National Institute of Genetics, and Department of Genetics, The Graduate University for Advanced Studies, Mishima 411-8540, Japan
| | - Takeshi Ishihara
- Structural Biology Center, National Institute of Genetics, and Department of Genetics, The Graduate University for Advanced Studies, Mishima 411-8540, Japan
| | - Isao Katsura
- Structural Biology Center, National Institute of Genetics, and Department of Genetics, The Graduate University for Advanced Studies, Mishima 411-8540, Japan
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Woo K, Jensen-Smith HC, Ludueña RF, Hallworth R. Differential synthesis of beta-tubulin isotypes in gerbil nasal epithelia. Cell Tissue Res 2002; 309:331-5. [PMID: 12172793 PMCID: PMC1992265 DOI: 10.1007/s00441-002-0591-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2001] [Accepted: 04/29/2002] [Indexed: 11/29/2022]
Abstract
Compartmentalization of beta-tubulin isotypes within cells according to function was examined in gerbil olfactory and respiratory epithelia by using specific antibodies to four beta-tubulin isotypes (beta(I), beta(II), beta(III), and beta(IV)). Isotype synthesis was cell-type-specific, but the localization of the isotypes was not compartmentalized. All four isotypes were found in the cilia, dendrites, somata, and axons of olfactory neurons. Only two isotypes (beta(I) and beta(IV)) were present in the cilia of nasal respiratory epithelial cells. The beta(IV) isotype, thought to be an essential component of cilia, was present in olfactory neurons and respiratory epithelial cells, which are ciliated, but was not found in basal cells (the stem cells of olfactory sensory neurons, which have no cilia). Olfactory neurons therefore do not synthesize beta(IV)-tubulin until they mature, when functioning cilia are also elaborated. The failure to observe compartmentalization of beta-tubulin isotypes in olfactory neurons sheds new light on potential functions of the beta-tubulin isotypes.
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Affiliation(s)
- Karen Woo
- The Medical School, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229-3900, USA
| | | | - Richard F. Ludueña
- Department of Biochemistry, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229-3900, USA
| | - Richard Hallworth
- Department of Biomedical Sciences, Creighton University, Omaha, NE 68178, USA, e-mail: Tel.: +1-402-2803057, Fax: +1-402-2802690
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Abstract
The Caenorhabditis elegans AWA, AWB, and AWC olfactory neurons are each required for the recognition of a specific subset of volatile odorants. lim-4 mutants express an AWC reporter gene inappropriately in the AWB olfactory neurons and fail to express an AWB reporter gene. The AWB cells are morphologically transformed toward an AWC fate in lim-4 mutants, adopting cilia and axon morphologies characteristic of AWC. AWB function is also transformed in these mutants: Rather than mediating the repulsive behavioral responses appropriate for AWB, the AWB neurons mediate attractive responses, like AWC. LIM-4 is a predicted LIM homeobox gene that is expressed in AWB and a few other head neurons. Ectopic expression of LIM-4 in the AWC neuron pair is sufficient to force those cells to adopt an AWB fate. The AWA nuclear hormone receptor ODR-7 described previously also represses AWC genes, as well as inducing AWA genes. We propose that the LIM-4 and ODR-7 transcription factors function to diversify C. elegans olfactory neuron identities, driving them from an AWC-like state into alternative fates.
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Affiliation(s)
- A Sagasti
- Howard Hughes Medical Institute, Department of Anatomy and Department of Biochemistry and Biophysics, University of California, San Francisco, California 94143-0452 USA
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