1
|
Naffaa MM. Neurogenesis dynamics in the olfactory bulb: deciphering circuitry organization, function, and adaptive plasticity. Neural Regen Res 2025; 20:1565-1581. [PMID: 38934393 DOI: 10.4103/nrr.nrr-d-24-00312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Accepted: 05/31/2024] [Indexed: 06/28/2024] Open
Abstract
Adult neurogenesis persists after birth in the subventricular zone, with new neurons migrating to the granule cell layer and glomerular layers of the olfactory bulb, where they integrate into existing circuitry as inhibitory interneurons. The generation of these new neurons in the olfactory bulb supports both structural and functional plasticity, aiding in circuit remodeling triggered by memory and learning processes. However, the presence of these neurons, coupled with the cellular diversity within the olfactory bulb, presents an ongoing challenge in understanding its network organization and function. Moreover, the continuous integration of new neurons in the olfactory bulb plays a pivotal role in regulating olfactory information processing. This adaptive process responds to changes in epithelial composition and contributes to the formation of olfactory memories by modulating cellular connectivity within the olfactory bulb and interacting intricately with higher-order brain regions. The role of adult neurogenesis in olfactory bulb functions remains a topic of debate. Nevertheless, the functionality of the olfactory bulb is intricately linked to the organization of granule cells around mitral and tufted cells. This organizational pattern significantly impacts output, network behavior, and synaptic plasticity, which are crucial for olfactory perception and memory. Additionally, this organization is further shaped by axon terminals originating from cortical and subcortical regions. Despite the crucial role of olfactory bulb in brain functions and behaviors related to olfaction, these complex and highly interconnected processes have not been comprehensively studied as a whole. Therefore, this manuscript aims to discuss our current understanding and explore how neural plasticity and olfactory neurogenesis contribute to enhancing the adaptability of the olfactory system. These mechanisms are thought to support olfactory learning and memory, potentially through increased complexity and restructuring of neural network structures, as well as the addition of new granule granule cells that aid in olfactory adaptation. Additionally, the manuscript underscores the importance of employing precise methodologies to elucidate the specific roles of adult neurogenesis amidst conflicting data and varying experimental paradigms. Understanding these processes is essential for gaining insights into the complexities of olfactory function and behavior.
Collapse
Affiliation(s)
- Moawiah M Naffaa
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
- Department of Cell Biology, Duke University School of Medicine, Durham, NC, USA
| |
Collapse
|
2
|
Hao Y, Wang Z, Li Q. Modulation of olfactory bulb activity by serotoninergic inputs in odor-associative learning. Acta Physiol (Oxf) 2024:e14222. [PMID: 39189694 DOI: 10.1111/apha.14222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2024] [Accepted: 08/15/2024] [Indexed: 08/28/2024]
Affiliation(s)
- Yue Hao
- Department of Otolaryngology, Songjiang Hospital and Songjiang Research Institute, Shanghai Key Laboratory of Emotions and Affective Disorders, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Department of Anatomy and Physiology, Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health in Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zheng Wang
- Department of Otolaryngology, Songjiang Hospital and Songjiang Research Institute, Shanghai Key Laboratory of Emotions and Affective Disorders, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qian Li
- Department of Otolaryngology, Songjiang Hospital and Songjiang Research Institute, Shanghai Key Laboratory of Emotions and Affective Disorders, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Department of Anatomy and Physiology, Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health in Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| |
Collapse
|
3
|
Cieri F, Giriprakash PP, Nandy R, Zhuang X, Doty RL, Caldwell JZK, Cordes D. Functional connectivity differences of the olfactory network in Parkinson's Disease, mild cognitive impairment and cognitively normal individuals: A resting-state fMRI study. Neuroscience 2024; 559:8-16. [PMID: 39179019 DOI: 10.1016/j.neuroscience.2024.08.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 07/26/2024] [Accepted: 08/20/2024] [Indexed: 08/26/2024]
Abstract
Olfactory dysfunction is an early sign of such neurodegenerative diseases as Parkinson's (PD) and Alzheimer's (AD), and is often present in Mild Cognitive Impairment (MCI), a precursor of AD. Understanding neuro-temporal relationships, i.e., functional connectivity, between olfactory eloquent structures in such disorders, could shed light on their basic pathophysiology. To this end, we employed region-based analyses using resting-state functional magnetic resonance imaging (rs-fMRI) obtained from cognitively normal (CN), MCI, and PD patients with cognitive impairment (PD-CogImp). Using machine learning (linear and ensemble learning), we determined whether the identified functional patterns could classify abnormal function from normal function. Olfaction, as measured by objective testing, was found to be most strongly associated with diagnostic status, emphasizing the fundamental association of this primary sensory system with these conditions. Consistently lower functional connectivity was observed in the PD-CogImp cohort compared to the CN cohort among all identified brain regions. Differences were also found between PD-CogImp and MCI at the level of the orbitofrontal and cingulate cortices. MCI and CN subjects had different functional connectivity between the posterior orbitofrontal cortex and thalamus. Regardless of study group, males showed significantly higher connectivity than females in connections involving the orbitofrontal cortex. The logistic regression model trained using the top discriminatory features revealed that caudate was the most involved olfaction-related brain structure (accuracy = 0.88, Area under the Receiver operator characteristic curve of 0.90). In aggregate, our study demonstrates that resting functional connectivity among olfactory eloquent structures has potential value in better understanding the pathophysiology of several neurodegenerative diseases.
Collapse
Affiliation(s)
- F Cieri
- Department of Neurology, Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV 89106, USA.
| | - P P Giriprakash
- Department of Neurology, Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV 89106, USA
| | - R Nandy
- Department of Biostatistics & Epidemiology, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - X Zhuang
- Department of Neurology, Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV 89106, USA
| | - R L Doty
- Smell and Taste Center, Department of Otorhinolaryngology, Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - J Z K Caldwell
- Department of Neurology, Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV 89106, USA
| | - D Cordes
- Department of Neurology, Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV 89106, USA; Department of Psychology and Neuroscience, University of Colorado, Boulder, CO 80309, USA
| |
Collapse
|
4
|
Zhang YJ, Lee JY, Igarashi KM. Circuit dynamics of the olfactory pathway during olfactory learning. Front Neural Circuits 2024; 18:1437575. [PMID: 39036422 PMCID: PMC11258029 DOI: 10.3389/fncir.2024.1437575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2024] [Accepted: 06/20/2024] [Indexed: 07/23/2024] Open
Abstract
The olfactory system plays crucial roles in perceiving and interacting with their surroundings. Previous studies have deciphered basic odor perceptions, but how information processing in the olfactory system is associated with learning and memory is poorly understood. In this review, we summarize recent studies on the anatomy and functional dynamics of the mouse olfactory learning pathway, focusing on how neuronal circuits in the olfactory bulb (OB) and olfactory cortical areas integrate odor information in learning. We also highlight in vivo evidence for the role of the lateral entorhinal cortex (LEC) in olfactory learning. Altogether, these studies demonstrate that brain regions throughout the olfactory system are critically involved in forming and representing learned knowledge. The role of olfactory areas in learning and memory, and their susceptibility to dysfunction in neurodegenerative diseases, necessitate further research.
Collapse
Affiliation(s)
- Yutian J. Zhang
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, Irvine, United States
| | - Jason Y. Lee
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, Irvine, United States
| | - Kei M. Igarashi
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, Irvine, United States
- Department of Biomedical Engineering, Samueli School of Engineering, University of California, Irvine, Irvine, United States
- Center for Neural Circuit Mapping, School of Medicine, University of California, Irvine, Irvine, United States
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, United States
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, United States
| |
Collapse
|
5
|
Fulton KA, Zimmerman D, Samuel A, Vogt K, Datta SR. Common principles for odour coding across vertebrates and invertebrates. Nat Rev Neurosci 2024; 25:453-472. [PMID: 38806946 DOI: 10.1038/s41583-024-00822-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/30/2024] [Indexed: 05/30/2024]
Abstract
The olfactory system is an ideal and tractable system for exploring how the brain transforms sensory inputs into behaviour. The basic tasks of any olfactory system include odour detection, discrimination and categorization. The challenge for the olfactory system is to transform the high-dimensional space of olfactory stimuli into the much smaller space of perceived objects and valence that endows odours with meaning. Our current understanding of how neural circuits address this challenge has come primarily from observations of the mechanisms of the brain for processing other sensory modalities, such as vision and hearing, in which optimized deep hierarchical circuits are used to extract sensory features that vary along continuous physical dimensions. The olfactory system, by contrast, contends with an ill-defined, high-dimensional stimulus space and discrete stimuli using a circuit architecture that is shallow and parallelized. Here, we present recent observations in vertebrate and invertebrate systems that relate the statistical structure and state-dependent modulation of olfactory codes to mechanisms of perception and odour-guided behaviour.
Collapse
Affiliation(s)
- Kara A Fulton
- Department of Neuroscience, Harvard Medical School, Boston, MA, USA
| | - David Zimmerman
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Aravi Samuel
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Katrin Vogt
- Department of Physics, Harvard University, Cambridge, MA, USA.
- Department of Biology, University of Konstanz, Konstanz, Germany.
- Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Konstanz, Germany.
| | | |
Collapse
|
6
|
McKissick O, Klimpert N, Ritt JT, Fleischmann A. Odors in space. Front Neural Circuits 2024; 18:1414452. [PMID: 38978957 PMCID: PMC11228174 DOI: 10.3389/fncir.2024.1414452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Accepted: 05/29/2024] [Indexed: 07/10/2024] Open
Abstract
As an evolutionarily ancient sense, olfaction is key to learning where to find food, shelter, mates, and important landmarks in an animal's environment. Brain circuitry linking odor and navigation appears to be a well conserved multi-region system among mammals; the anterior olfactory nucleus, piriform cortex, entorhinal cortex, and hippocampus each represent different aspects of olfactory and spatial information. We review recent advances in our understanding of the neural circuits underlying odor-place associations, highlighting key choices of behavioral task design and neural circuit manipulations for investigating learning and memory.
Collapse
Affiliation(s)
- Olivia McKissick
- Department of Neuroscience and Carney Institute for Brain Science, Brown University, Providence, RI, United States
| | - Nell Klimpert
- Department of Neuroscience and Carney Institute for Brain Science, Brown University, Providence, RI, United States
| | - Jason T Ritt
- Carney Institute for Brain Science, Brown University, Providence, RI, United States
| | - Alexander Fleischmann
- Department of Neuroscience and Carney Institute for Brain Science, Brown University, Providence, RI, United States
| |
Collapse
|
7
|
Li H, Qian J, Wang Y, Wang J, Mi X, Qu L, Song N, Xie J. Potential convergence of olfactory dysfunction in Parkinson's disease and COVID-19: The role of neuroinflammation. Ageing Res Rev 2024; 97:102288. [PMID: 38580172 DOI: 10.1016/j.arr.2024.102288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 03/28/2024] [Accepted: 03/30/2024] [Indexed: 04/07/2024]
Abstract
Parkinson's disease (PD) is a prevalent neurodegenerative disorder that affects 7-10 million individuals worldwide. A common early symptom of PD is olfactory dysfunction (OD), and more than 90% of PD patients suffer from OD. Recent studies have highlighted a high incidence of OD in patients with SARS-CoV-2 infection. This review investigates the potential convergence of OD in PD and COVID-19, particularly focusing on the mechanisms by which neuroinflammation contributes to OD and neurological events. Starting from our fundamental understanding of the olfactory bulb, we summarize the clinical features of OD and pathological features of the olfactory bulb from clinical cases and autopsy reports in PD patients. We then examine SARS-CoV-2-induced olfactory bulb neuropathology and OD and emphasize the SARS-CoV-2-induced neuroinflammatory cascades potentially leading to PD manifestations. By activating microglia and astrocytes, as well as facilitating the aggregation of α-synuclein, SARS-CoV-2 could contribute to the onset or exacerbation of PD. We also discuss the possible contributions of NF-κB, the NLRP3 inflammasome, and the JAK/STAT, p38 MAPK, TLR4, IL-6/JAK2/STAT3 and cGAS-STING signaling pathways. Although olfactory dysfunction in patients with COVID-19 may be reversible, it is challenging to restore OD in patients with PD. With the emergence of new SARS-CoV-2 variants and the recurrence of infections, we call for continued attention to the intersection between PD and SARS-CoV-2 infection, especially from the perspective of OD.
Collapse
Affiliation(s)
- Hui Li
- Institute of Brain Science and Disease, Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, China
| | - Junliang Qian
- Institute of Brain Science and Disease, Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, China
| | - Youcui Wang
- Institute of Brain Science and Disease, Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, China
| | - Juan Wang
- Institute of Brain Science and Disease, Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, China
| | - Xiaoqing Mi
- Institute of Brain Science and Disease, Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, China
| | - Le Qu
- Institute of Brain Science and Disease, Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, China
| | - Ning Song
- Institute of Brain Science and Disease, Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, China.
| | - Junxia Xie
- Institute of Brain Science and Disease, Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, China.
| |
Collapse
|
8
|
Chen HW, Ma CP, Chin E, Chen YT, Wang TC, Kuo YP, Su CH, Huang PJ, Tan BCM. Imbalance in Unc80 RNA Editing Disrupts Dynamic Neuronal Activity and Olfactory Perception. Int J Mol Sci 2024; 25:5985. [PMID: 38892173 PMCID: PMC11172567 DOI: 10.3390/ijms25115985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Revised: 05/22/2024] [Accepted: 05/28/2024] [Indexed: 06/21/2024] Open
Abstract
A-to-I RNA editing, catalyzed by the ADAR protein family, significantly contributes to the diversity and adaptability of mammalian RNA signatures, aligning with developmental and physiological needs. Yet, the functions of many editing sites are still to be defined. The Unc80 gene stands out in this context due to its brain-specific expression and the evolutionary conservation of its codon-altering editing event. The precise biological functions of Unc80 and its editing, however, are still largely undefined. In this study, we first demonstrated that Unc80 editing occurs in an ADAR2-dependent manner and is exclusive to the brain. By employing the CRISPR/Cas9 system to generate Unc80 knock-in mouse models that replicate the natural editing variations, our findings revealed that mice with the "gain-of-editing" variant (Unc80G/G) exhibit heightened basal neuronal activity in critical olfactory regions, compared to the "loss-of-editing" (Unc80S/S) counterparts. Moreover, an increase in glutamate levels was observed in the olfactory bulbs of Unc80G/G mice, indicating altered neurotransmitter dynamics. Behavioral analysis of odor detection revealed distinctive responses to novel odors-both Unc80 deficient (Unc80+/-) and Unc80S/S mice demonstrated prolonged exploration times and heightened dishabituation responses. Further elucidating the olfactory connection of Unc80 editing, transcriptomic analysis of the olfactory bulb identified significant alterations in gene expression that corroborate the behavioral and physiological findings. Collectively, our research advances the understanding of Unc80's neurophysiological functions and the impact of its editing on the olfactory sensory system, shedding light on the intricate molecular underpinnings of olfactory perception and neuronal activity.
Collapse
Affiliation(s)
- Hui-Wen Chen
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan; (H.-W.C.); (C.-P.M.); (E.C.); (Y.-T.C.); (P.-J.H.)
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan;
| | - Chung-Pei Ma
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan; (H.-W.C.); (C.-P.M.); (E.C.); (Y.-T.C.); (P.-J.H.)
| | - En Chin
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan; (H.-W.C.); (C.-P.M.); (E.C.); (Y.-T.C.); (P.-J.H.)
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan;
| | - Yi-Tung Chen
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan; (H.-W.C.); (C.-P.M.); (E.C.); (Y.-T.C.); (P.-J.H.)
- Molecular Medicine Research Center, Chang Gung University, Taoyuan 333, Taiwan;
| | - Teh-Cheng Wang
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan;
| | - Yu-Ping Kuo
- Molecular Medicine Research Center, Chang Gung University, Taoyuan 333, Taiwan;
| | - Chia-Hao Su
- Center for General Education, Chang Gung University, Taoyuan 333, Taiwan;
- Department of Radiation Oncology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan
| | - Po-Jung Huang
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan; (H.-W.C.); (C.-P.M.); (E.C.); (Y.-T.C.); (P.-J.H.)
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan;
- Genomic Medicine Core Laboratory, Lin-Kou Medical Center, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan
| | - Bertrand Chin-Ming Tan
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan; (H.-W.C.); (C.-P.M.); (E.C.); (Y.-T.C.); (P.-J.H.)
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan;
- Division of Colon and Rectal Surgery, Lin-Kou Medical Center, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan
- Department of Neurosurgery, Lin-Kou Medical Center, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan
| |
Collapse
|
9
|
Tran KN, Kwon JH, Kim MK, Nguyen NPK, Yang IJ. Intranasal delivery of herbal medicine for disease treatment: A systematic review. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2024; 127:155484. [PMID: 38442431 DOI: 10.1016/j.phymed.2024.155484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 02/01/2024] [Accepted: 02/24/2024] [Indexed: 03/07/2024]
Abstract
BACKGROUND Intranasal administration has been adopted in traditional medicine to facilitate access to the bloodstream and central nervous system (CNS). In modern medicine, nasal drug delivery systems are valuable for disease treatment because of their noninvasiveness, good absorption, and fast-acting effects. OBJECTIVE This study aimed to systematically organize preclinical and clinical studies on intranasal herbal medicines to highlight their potential in drug development. METHODS A comprehensive search for literature until February 2023 was conducted on PubMed and the Web of Science. From the selected publications, we extracted key information, including the types of herbal materials, target diseases, intranasal conditions, methods of toxicity evaluation, main outcomes, and mechanisms of action, and performed quality assessments for each study. RESULTS Of the 45 studies, 13 were clinical and 32 were preclinical; 28 studies used herbal extracts, 9 used prescriptions, and 8 used natural compounds. The target diseases were rhinosinusitis, influenza, fever, stroke, migraine, insomnia, depression, memory disorders, and lung cancer. The common intranasal volumes were 8-50 µl in mice, 20-100 µl in rats, and 100-500 µl in rabbits. Peppermint oil, Ribes nigrum folium, Melia azedarach L., Elaeocarpus sylvestris, Radix Bupleuri, Da Chuan Xiong Fang, Xingnaojing microemulsion, and Ginsenoside Rb1 emerged as potential candidates for rapid intranasal therapy. The in vivo toxicity assessments were based on mortality, body weight, behavioral changes, mucociliary activity, histopathology, and blood tests. Most intranasal treatments were safe, except for Cyclamen europaeum, Jasminum sambac, Punica granatum L., and violet oil, which caused mild adverse effects. At lower doses, intranasal herbal treatments often show greater effects than oral administration. The actions of intranasal herbal medicine mainly involve regulating inflammation and neurotransmission, with the olfactory bulb and anterior cingulate cortex to be relevant brain regions. CONCLUSION Intranasal delivery of herbal materials holds promise for enhancing drug delivery efficacy and reducing treatment duration, offering a potential future perspective for developing intranasal therapies for various diseases.
Collapse
Affiliation(s)
- Khoa Nguyen Tran
- Department of Physiology, College of Korean Medicine, Dongguk University, Gyeongju, 38066, Republic of Korea
| | - Ji-Hye Kwon
- Department of Physiology, College of Korean Medicine, Dongguk University, Gyeongju, 38066, Republic of Korea
| | - Min-Kyung Kim
- Department of Physiology, College of Korean Medicine, Dongguk University, Gyeongju, 38066, Republic of Korea
| | - Nhi Phuc Khanh Nguyen
- Department of Physiology, College of Korean Medicine, Dongguk University, Gyeongju, 38066, Republic of Korea
| | - In-Jun Yang
- Department of Physiology, College of Korean Medicine, Dongguk University, Gyeongju, 38066, Republic of Korea.
| |
Collapse
|
10
|
Pardasani M, Ramakrishnan AM, Mahajan S, Kantroo M, McGowan E, Das S, Srikanth P, Pandey S, Abraham NM. Perceptual learning deficits mediated by somatostatin releasing inhibitory interneurons of olfactory bulb in an early life stress mouse model. Mol Psychiatry 2023; 28:4693-4706. [PMID: 37726451 PMCID: PMC10914616 DOI: 10.1038/s41380-023-02244-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 08/21/2023] [Accepted: 08/25/2023] [Indexed: 09/21/2023]
Abstract
Early life adversity (ELA) causes aberrant functioning of neural circuits affecting the health of an individual. While ELA-induced behavioural disorders resulting from sensory and cognitive disabilities can be assessed clinically, the neural mechanisms need to be probed using animal models by employing multi-pronged experimental approaches. As ELA can alter sensory perception, we investigated the effect of early weaning on murine olfaction. By implementing go/no-go odour discrimination paradigm, we observed olfactory learning and memory impairments in early life stressed (ELS) male mice. As olfactory bulb (OB) circuitry plays a critical role in odour learning, we studied the plausible changes in the OB of ELS mice. Lowered c-Fos activity in the external plexiform layer and a reduction in the number of dendritic processes of somatostatin-releasing, GABAergic interneurons (SOM-INs) in the ELS mice led us to hypothesise the underlying circuit. We recorded reduced synaptic inhibitory feedback on mitral/tufted (M/T) cells, in the OB slices from ELS mice, explaining the learning deficiency caused by compromised refinement of OB output. The reduction in synaptic inhibition was nullified by the photo-activation of ChR2-expressing SOM-INs in ELS mice. The role of SOM-INs was revealed by learning-dependent refinement of Ca2+dynamics quantified by GCaMP6f signals, which was absent in ELS mice. Further, the causal role of SOM-INs involving circuitry was investigated by optogenetic modulation during the odour discrimination learning. Photo-activating these neurons rescued the ELA-induced learning deficits. Conversely, photo-inhibition caused learning deficiency in control animals, while it completely abolished the learning in ELS mice, confirming the adverse effects mediated by SOM-INs. Our results thus establish the role of specific inhibitory circuit in pre-cortical sensory area in orchestrating ELA-dependent changes.
Collapse
Affiliation(s)
- Meenakshi Pardasani
- Laboratory of Neural Circuits and Behaviour (LNCB), Department of Biology, Indian Institute of Science Education and Research (IISER), Pune, Maharashtra, 411008, India
| | - Anantha Maharasi Ramakrishnan
- Laboratory of Neural Circuits and Behaviour (LNCB), Department of Biology, Indian Institute of Science Education and Research (IISER), Pune, Maharashtra, 411008, India
| | - Sarang Mahajan
- Laboratory of Neural Circuits and Behaviour (LNCB), Department of Biology, Indian Institute of Science Education and Research (IISER), Pune, Maharashtra, 411008, India
| | - Meher Kantroo
- Laboratory of Neural Circuits and Behaviour (LNCB), Department of Biology, Indian Institute of Science Education and Research (IISER), Pune, Maharashtra, 411008, India
| | - Eleanor McGowan
- Laboratory of Neural Circuits and Behaviour (LNCB), Department of Biology, Indian Institute of Science Education and Research (IISER), Pune, Maharashtra, 411008, India
| | - Susobhan Das
- Laboratory of Neural Circuits and Behaviour (LNCB), Department of Biology, Indian Institute of Science Education and Research (IISER), Pune, Maharashtra, 411008, India
| | - Priyadharshini Srikanth
- Laboratory of Neural Circuits and Behaviour (LNCB), Department of Biology, Indian Institute of Science Education and Research (IISER), Pune, Maharashtra, 411008, India
| | - Sanyukta Pandey
- Laboratory of Neural Circuits and Behaviour (LNCB), Department of Biology, Indian Institute of Science Education and Research (IISER), Pune, Maharashtra, 411008, India
| | - Nixon M Abraham
- Laboratory of Neural Circuits and Behaviour (LNCB), Department of Biology, Indian Institute of Science Education and Research (IISER), Pune, Maharashtra, 411008, India.
| |
Collapse
|
11
|
Lacoursiere SG, McAllister BB, Hadikin C, Tschetter WW, Lehmann H, Sutherland RJ. Hippocampal damage causes retrograde amnesia for objects' visual, but not odour, properties in male rats. Eur J Neurosci 2023; 58:3618-3629. [PMID: 37723853 DOI: 10.1111/ejn.16141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 07/31/2023] [Accepted: 08/21/2023] [Indexed: 09/20/2023]
Abstract
Damage to the hippocampus produces profound retrograde amnesia, but odour and object discrimination memories can be spared in the retrograde direction. Prior lesion studies testing retrograde amnesia for object/odour discriminations are problematic due to sparing of large parts of the hippocampus, which may support memory recall, and/or the presence of uncontrolled, distinctive odours that may support object discrimination. To address these issues, we used a simple object discrimination test to assess memory in male rats. Two visually distinct objects, paired with distinct odour cues, were presented. One object was associated with a reward. Following training, neurotoxic hippocampal lesions were made using N-methyl-D-aspartate (NMDA). The rats were then tested on the preoperatively learned object discrimination problem, with and without the availability of odour or visual cues during testing. The rats were also postoperatively trained on a new object discrimination problem. Lesion sizes ranged from 67% to 97% of the hippocampus (average of 87%). On the preoperatively learned discrimination problem, the rats with hippocampal lesions showed preserved object discrimination memory when tested in the dark (i.e., without visual cues) but not when the explicit odour cues were removed from the objects. Hippocampal lesions increased the number of trials required to reach criterion but did not prevent rats from solving the postoperatively learned discrimination problem. Our results support the idea that long-term memories for odours, unlike recall of visual properties of objects, do not depend on the hippocampus in rats, consistent with previous observations that hippocampal damage does not cause retrograde amnesia for odour memories.
Collapse
Affiliation(s)
- Sean G Lacoursiere
- Department of Neuroscience, Canadian Centre for Behavioural Neuroscience, The University of Lethbridge, Lethbridge, Alberta, Canada
| | - Brendan B McAllister
- Department of Neuroscience, Canadian Centre for Behavioural Neuroscience, The University of Lethbridge, Lethbridge, Alberta, Canada
| | - Crystal Hadikin
- Department of Neuroscience, Canadian Centre for Behavioural Neuroscience, The University of Lethbridge, Lethbridge, Alberta, Canada
- Canadian School of Natural Nutrition, Sooke, British Columbia, Canada
| | - Wayne W Tschetter
- Department of Neuroscience, Canadian Centre for Behavioural Neuroscience, The University of Lethbridge, Lethbridge, Alberta, Canada
- Department of Ophthalmology, Oregon Health and Science University, Portland, Oregon, USA
| | - Hugo Lehmann
- Department of Psychology, Trent University, Peterborough, Ontario, Canada
| | - Robert J Sutherland
- Department of Neuroscience, Canadian Centre for Behavioural Neuroscience, The University of Lethbridge, Lethbridge, Alberta, Canada
| |
Collapse
|
12
|
Silvas-Baltazar M, López-Oropeza G, Durán P, Martínez-Canabal A. Olfactory neurogenesis and its role in fear memory modulation. Front Behav Neurosci 2023; 17:1278324. [PMID: 37840547 PMCID: PMC10569173 DOI: 10.3389/fnbeh.2023.1278324] [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: 08/16/2023] [Accepted: 09/12/2023] [Indexed: 10/17/2023] Open
Abstract
Olfaction is a critical sense that allows animals to navigate and understand their environment. In mammals, the critical brain structure to receive and process olfactory information is the olfactory bulb, a structure characterized by a laminated pattern with different types of neurons, some of which project to distant telencephalic structures, like the piriform cortex, the amygdala, and the hippocampal formation. Therefore, the olfactory bulb is the first structure of a complex cognitive network that relates olfaction to different types of memory, including episodic memories. The olfactory bulb continuously adds inhibitory newborn neurons throughout life; these cells locate both in the granule and glomerular layers and integrate into the olfactory circuits, inhibiting projection neurons. However, the roles of these cells modulating olfactory memories are unclear, particularly their role in fear memories. We consider that olfactory neurogenesis might modulate olfactory fear memories by a plastic process occurring in the olfactory bulb.
Collapse
Affiliation(s)
- Monserrat Silvas-Baltazar
- Licenciatura en Neurociencias, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
- Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Grecia López-Oropeza
- Licenciatura en Neurociencias, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
- Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
- Posgrado en Ciencias Biológicas, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Pilar Durán
- Licenciatura en Neurociencias, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
- Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
- Posgrado en Ciencias Biológicas, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Alonso Martínez-Canabal
- Licenciatura en Neurociencias, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
- Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
- Posgrado en Ciencias Biológicas, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| |
Collapse
|
13
|
Malone CL, Rieger NS, Spool JA, Payette A, Riters LV, Marler CA. Behavioral convergence in defense behaviors in pair bonded individuals correlates with neuroendocrine receptors in the medial amygdala. Behav Brain Res 2023; 452:114556. [PMID: 37356669 PMCID: PMC10644349 DOI: 10.1016/j.bbr.2023.114556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 06/19/2023] [Accepted: 06/22/2023] [Indexed: 06/27/2023]
Abstract
Monogamous, pair-bonded animals coordinate intra-pair behavior for spatially separated challenges including territorial defense and nest attendance. Paired California mice, a monogamous, territorial and biparental species, approach intruders together or separately, but often express behavioral convergence across intruder challenges. To gain a more systems-wide perspective of potential mechanisms contributing to behavioral convergence across two conspecific intruder challenges, we conducted an exploratory study correlating behavior and receptor mRNA (Days 10 and 17 post-pairing). We examined associations between convergence variability in pair time for intruder-oriented behaviors with a pair mRNA index for oxytocin (OXTR), androgen (AR), and estrogen alpha (ERα) receptors within the medial amygdala (MeA) and the anterior olfactory nucleus (AON), brain regions associated with social behavior. An intruder behavior index revealed a bimodal distribution of intruder-related behaviors in Challenge 1 and a unimodal distribution in Challenge 2, suggesting population behavioral convergence, but no significant correlations with neuroendocrine measures. However, OXTR, AR, and ERα mRNA in the MeA were positively associated with convergence in individual intruder-related behaviors, suggesting multiple mechanisms may influence convergence. Mice could also occupy the nest during intruder challenges and convergence in nest attendance was positively correlated with MeA OXTR. At an individual level, nest attendance was positively associated with MeA ERα. Vocalizations were positively associated with AR and ERα mRNA. No positive associations were found in the AON. Overall, neuroendocrine receptors were implicated in convergence of a monogamous pair's defense behavior, highlighting the potential importance of the MeA as part of a circuit underlying convergence.
Collapse
Affiliation(s)
- Candice L Malone
- University of Wisconsin-Madison, Department of Psychology, Madison, WI, USA.
| | - Nathaniel S Rieger
- University of Wisconsin-Madison, Department of Psychology, Madison, WI, USA; University of Washington-Seattle, Department of Psychiatry and Behavioral Sciences, Seattle, WA, USA
| | - Jeremy A Spool
- University of Wisconsin-Madison, Department of Integrative Biology, Madison, WI, USA; University of Massachusetts-Amherst, Department of Psychological and Brain Sciences, Amherst, MA, USA
| | - Alexis Payette
- University of Wisconsin-Madison, Department of Psychology, Madison, WI, USA
| | - Lauren V Riters
- University of Wisconsin-Madison, Department of Integrative Biology, Madison, WI, USA
| | - Catherine A Marler
- University of Wisconsin-Madison, Department of Psychology, Madison, WI, USA.
| |
Collapse
|
14
|
Brunert D, Quintela RM, Rothermel M. The anterior olfactory nucleus revisited - an emerging role for neuropathological conditions? Prog Neurobiol 2023:102486. [PMID: 37343762 DOI: 10.1016/j.pneurobio.2023.102486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 06/14/2023] [Accepted: 06/16/2023] [Indexed: 06/23/2023]
Abstract
Olfaction is an important sensory modality for many species and greatly influences animal and human behavior. Still, much about olfactory perception remains unknown. The anterior olfactory nucleus is one of the brain's central early olfactory processing areas. Located directly posterior to the olfactory bulb in the olfactory peduncle with extensive in- and output connections and unique cellular composition, it connects olfactory processing centers of the left and right hemispheres. Almost 20 years have passed since the last comprehensive review on the anterior olfactory nucleus has been published and significant advances regarding its anatomy, function, and pathophysiology have been made in the meantime. Here we briefly summarize previous knowledge on the anterior olfactory nucleus, give detailed insights into the progress that has been made in recent years, and map out its emerging importance in translational research of neurological diseases.
Collapse
Affiliation(s)
- Daniela Brunert
- Institute of Physiology, Medical Faculty, Otto-von-Guericke-University, 39120 Magdeburg, Germany
| | | | - Markus Rothermel
- Institute of Physiology, Medical Faculty, Otto-von-Guericke-University, 39120 Magdeburg, Germany.
| |
Collapse
|
15
|
Lu MH, Uematsu A, Kiyokawa Y, Emoto K, Takeuchi Y. Glutamatergic Projections from the Posterior Complex of the Anterior Olfactory Nucleus to the Amygdala Complexes. Neuroscience 2023; 521:102-109. [PMID: 37142179 DOI: 10.1016/j.neuroscience.2023.04.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 04/17/2023] [Accepted: 04/25/2023] [Indexed: 05/06/2023]
Abstract
Social buffering is a phenomenon where stress responses are ameliorated by an affiliative conspecific. Our previous findings suggest that the posterior complex of the anterior olfactory nucleus (AOP) is well positioned to participate in the neural mechanisms underlying social buffering. However, the lack of anatomical information prevents us from further estimating the role of the AOP. Here, we obtained anatomical information regarding the AOP in male rats. In Experiment 1 (n = 5), among 4',6-diamidino-2-phenylindole-positive cells in the AOP, the proportion of glutamic acid decarboxylase 67 (GAD67)-positive cells was 13.8% ± 1.2%. In Experiment 2 (n = 5), among the cells that were labeled by a retrograde tracer injected into the basolateral complex of the amygdala (BLA), the proportion of GAD67-positive cells was 18.6% ± 0.8%. In Experiment 3 (n = 5), we demonstrated the existence of cells that were labeled by the retrograde tracer injected into the posterior part of the medial amygdala (MeP), mostly into the ventral part of the MeP. In addition, the proportion of GAD67-positive cells among the tracer-labeled cells was 21.7% ± 1.7%. In Experiment 4 (n = 3), the retrograde tracers were injected into the BLA and MeP, mostly into the ventral part of the MeP. The proportion of double-labeled cells among the tracer-labeled cells was 2.1% ± 1.2%. Taken together, these results suggest that the AOP is predominantly composed of glutamatergic neurons. In addition, the AOP sends mutually independent glutamatergic-predominant projections to the BLA and MeP.
Collapse
Affiliation(s)
- Ming-Hsuan Lu
- Laboratory of Veterinary Ethology, The University of Tokyo, Japan
| | - Akira Uematsu
- International Research Center for Neurointelligence, The University of Tokyo, Japan; Graduate School of Science, The University of Tokyo, Japan; Present Adress: Human Informatics and Interaction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Japan
| | - Yasushi Kiyokawa
- Laboratory of Veterinary Ethology, The University of Tokyo, Japan.
| | - Kazuo Emoto
- International Research Center for Neurointelligence, The University of Tokyo, Japan; Graduate School of Science, The University of Tokyo, Japan
| | - Yukari Takeuchi
- Laboratory of Veterinary Ethology, The University of Tokyo, Japan
| |
Collapse
|
16
|
Cuevas JS, Watanabe M, Uematsu A, Johansen JP. Whole-brain afferent input mapping to functionally distinct brainstem noradrenaline cell types. Neurosci Res 2023:S0168-0102(23)00074-3. [PMID: 37062443 DOI: 10.1016/j.neures.2023.04.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 04/10/2023] [Accepted: 04/13/2023] [Indexed: 04/18/2023]
Abstract
The locus coeruleus (LC) is a small region in the pons and the main source of noradrenaline (NA) to the forebrain. While traditional models suggested that all LC-NA neurons project indiscriminately throughout the brain, accumulating evidence indicates that these cells can be heterogeneous based on their anatomical connectivity and behavioral functionality and exhibit distinct coding modes. How LC-NA neuronal subpopulations are endowed with unique functional properties is unclear. Here, we used a viral-genetic approach for mapping anatomical connectivity at different levels of organization based on inputs and outputs of defined cell classes. Specifically, we studied the whole-brain afferent inputs onto two functionally distinct LC-NA neuronal subpopulations which project to amygdala or medial prefrontal cortex (mPFC). We found that the global input distribution is similar for both LC-NA neuronal subpopulations. However, finer analysis demonstrated important differences in inputs from specific brain regions. Moreover, sex related differences were apparent, but only in inputs to amygdala-projecting LC-NA neurons. These findings reveal a cell type and sex specific afferent input organization which could allow for context dependent and target specific control of NA outflow to forebrain structures involved in emotional control and decision making.
Collapse
Affiliation(s)
- Jessica Sulkes Cuevas
- RIKEN Center for Brain Science, 2-1 Hirosawa, Wako-shi, Saitama, Japan 351-0198; Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Tokyo, 0Japan
| | - Mayumi Watanabe
- RIKEN Center for Brain Science, 2-1 Hirosawa, Wako-shi, Saitama, Japan 351-0198; Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Tokyo, 0Japan
| | - Akira Uematsu
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan; International Research Center for Neurointelligence, The University of Tokyo, Tokyo, Japan
| | - Joshua P Johansen
- RIKEN Center for Brain Science, 2-1 Hirosawa, Wako-shi, Saitama, Japan 351-0198; Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Tokyo, 0Japan.
| |
Collapse
|
17
|
Li Z, Chen L, Xu C, Chen Z, Wang Y. Non-invasive sensory neuromodulation in epilepsy: Updates and future perspectives. Neurobiol Dis 2023; 179:106049. [PMID: 36813206 DOI: 10.1016/j.nbd.2023.106049] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 02/15/2023] [Accepted: 02/16/2023] [Indexed: 02/22/2023] Open
Abstract
Epilepsy, one of the most common neurological disorders, often is not well controlled by current pharmacological and surgical treatments. Sensory neuromodulation, including multi-sensory stimulation, auditory stimulation, olfactory stimulation, is a kind of novel noninvasive mind-body intervention and receives continued attention as complementary safe treatment of epilepsy. In this review, we summarize the recent advances of sensory neuromodulation, including enriched environment therapy, music therapy, olfactory therapy, other mind-body interventions, for the treatment of epilepsy based on the evidence from both clinical and preclinical studies. We also discuss their possible anti-epileptic mechanisms on neural circuit level and propose perspectives on possible research directions for future studies.
Collapse
Affiliation(s)
- Zhongxia Li
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China; Zhejiang Rehabilitation Medical Center Department, The Third Affiliated Hospital, Zhejiang Chinese Medical University, Hangzhou, China
| | - Liying Chen
- Department of Pharmacy, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Cenglin Xu
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Zhong Chen
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Yi Wang
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China; Zhejiang Rehabilitation Medical Center Department, The Third Affiliated Hospital, Zhejiang Chinese Medical University, Hangzhou, China.
| |
Collapse
|
18
|
Wang Y, Zhao Q, Ma M, Xu J. Olfactory perception prediction model inspired by olfactory lateral inhibition and deep feature combination. APPL INTELL 2023. [DOI: 10.1007/s10489-023-04517-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2023]
|
19
|
Organizational Principles of the Centrifugal Projections to the Olfactory Bulb. Int J Mol Sci 2023; 24:ijms24054579. [PMID: 36902010 PMCID: PMC10002860 DOI: 10.3390/ijms24054579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2022] [Revised: 02/20/2023] [Accepted: 02/22/2023] [Indexed: 03/03/2023] Open
Abstract
Centrifugal projections in the olfactory system are critical to both olfactory processing and behavior. The olfactory bulb (OB), the first relay station in odor processing, receives a substantial number of centrifugal inputs from the central brain regions. However, the anatomical organization of these centrifugal connections has not been fully elucidated, especially for the excitatory projection neurons of the OB, the mitral/tufted cells (M/TCs). Using rabies virus-mediated retrograde monosynaptic tracing in Thy1-Cre mice, we identified that the three most prominent inputs of the M/TCs came from the anterior olfactory nucleus (AON), the piriform cortex (PC), and the basal forebrain (BF), similar to the granule cells (GCs), the most abundant population of inhibitory interneurons in the OB. However, M/TCs received proportionally less input from the primary olfactory cortical areas, including the AON and PC, but more input from the BF and contralateral brain regions than GCs. Unlike organizationally distinct inputs from the primary olfactory cortical areas to these two types of OB neurons, inputs from the BF were organized similarly. Furthermore, individual BF cholinergic neurons innervated multiple layers of the OB, forming synapses on both M/TCs and GCs. Taken together, our results indicate that the centrifugal projections to different types of OB neurons may provide complementary and coordinated strategies in olfactory processing and behavior.
Collapse
|
20
|
Oxidative Stress and Mitochondrial Complex I Dysfunction Correlate with Neurodegeneration in an α-Synucleinopathy Animal Model. Int J Mol Sci 2022; 23:ijms231911394. [PMID: 36232716 PMCID: PMC9570254 DOI: 10.3390/ijms231911394] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 09/03/2022] [Accepted: 09/05/2022] [Indexed: 11/16/2022] Open
Abstract
The α-synucleinopathies constitute a subset of neurodegenerative disorders, of which Parkinson’s disease (PD) is the most common worldwide, characterized by the accumulation of misfolded α-synuclein in the cytoplasm of neurons, which spreads in a prion-like manner to anatomically interconnected brain areas. However, it is not clear how α-synucleinopathy triggers neurodegeneration. We recently developed a rat model through a single intranigral administration of the neurotoxic β-sitosterol β-D-glucoside (BSSG), which produces α-synucleinopathy. In this model, we aimed to evaluate the temporal pattern of levels in oxidative and nitrosative stress and mitochondrial complex I (CI) dysfunction and how these biochemical parameters are associated with neurodegeneration in different brain areas with α-synucleinopathy (Substantia nigra pars compacta, the striatum, in the hippocampus and the olfactory bulb, where α-syn aggregation spreads). Interestingly, an increase in oxidative stress and mitochondrial CI dysfunction accompanied neurodegeneration in those brain regions. Furthermore, in silico analysis suggests a high-affinity binding site for BSSG with peroxisome proliferator-activated receptors (PPAR) alpha (PPAR-α) and gamma (PPAR-γ). These findings will contribute to elucidating the pathophysiological mechanisms associated with α-synucleinopathies and lead to the identification of new early biomarkers and therapeutic targets.
Collapse
|
21
|
Kulason S, Ratnanather JT, Miller MI, Kamath V, Hua J, Yang K, Ma M, Ishizuka K, Sawa A. A comparative neuroimaging perspective of olfaction and higher-order olfactory processing: on health and disease. Semin Cell Dev Biol 2022; 129:22-30. [PMID: 34462249 PMCID: PMC9900497 DOI: 10.1016/j.semcdb.2021.08.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Accepted: 08/18/2021] [Indexed: 02/08/2023]
Abstract
Olfactory dysfunction is often the earliest indicator of disease in a range of neurological and psychiatric disorders. One tempting working hypothesis is that pathological changes in the peripheral olfactory system where the body is exposed to many adverse environmental stressors may have a causal role for the brain alteration. Whether and how the peripheral pathology spreads to more central brain regions may be effectively studied in rodent models, and there is successful precedence in experimental models for Parkinson's disease. It is of interest to study whether a similar mechanism may underlie the pathology of psychiatric illnesses, such as schizophrenia. However, direct comparison between rodent models and humans includes challenges under light of comparative neuroanatomy and experimental methodologies used in these two distinct species. We believe that neuroimaging modality that has been the main methodology of human brain studies may be a useful viewpoint to address and fill the knowledge gap between rodents and humans in this scientific question. Accordingly, in the present review article, we focus on brain imaging studies associated with olfaction in healthy humans and patients with neurological and psychiatric disorders, and if available those in rodents. We organize this review article at three levels: 1) olfactory bulb (OB) and peripheral structures of the olfactory system, 2) primary olfactory cortical and subcortical regions, and 3) associated higher-order cortical regions. This research area is still underdeveloped, and we acknowledge that further validation with independent cohorts may be needed for many studies presented here, in particular those with human subjects. Nevertheless, whether and how peripheral olfactory disturbance impacts brain function is becoming even a hotter topic in the ongoing COVID-19 pandemic, given the risk of long-term changes of mental status associated with olfactory infection of SARS-CoV-2. Together, in this review article, we introduce this underdeveloped but important research area focusing on its implications in neurological and psychiatric disorders, with several pioneered publications.
Collapse
Affiliation(s)
- Sue Kulason
- Center for Imaging Science, Johns Hopkins University, Baltimore, MD, USA; Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD, USA; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - J Tilak Ratnanather
- Center for Imaging Science, Johns Hopkins University, Baltimore, MD, USA; Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD, USA; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Michael I Miller
- Center for Imaging Science, Johns Hopkins University, Baltimore, MD, USA; Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD, USA; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Vidyulata Kamath
- Department of Psychiatry, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Jun Hua
- Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Kun Yang
- Department of Psychiatry, Johns Hopkins School of Medicine, Baltimore, MD, USA; Johns Hopkins Schizophrenia Center, Baltimore, MD, USA
| | - Minghong Ma
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Koko Ishizuka
- Department of Psychiatry, Johns Hopkins School of Medicine, Baltimore, MD, USA; Johns Hopkins Schizophrenia Center, Baltimore, MD, USA
| | - Akira Sawa
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA; Department of Psychiatry, Johns Hopkins School of Medicine, Baltimore, MD, USA; Johns Hopkins Schizophrenia Center, Baltimore, MD, USA; Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, MD, USA; Department of Mental Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
| |
Collapse
|
22
|
Stensola T, Stensola H. Understanding Categorical Learning in Neural Circuits Through the Primary Olfactory Cortex. Front Cell Neurosci 2022; 16:920334. [PMID: 35813505 PMCID: PMC9263292 DOI: 10.3389/fncel.2022.920334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 05/30/2022] [Indexed: 11/25/2022] Open
Abstract
Knowing which elements in the environment are associated with various opportunities and dangers is advantageous. A major role of mammalian sensory systems is to provide information about the identity of such elements which can then be used for adaptive action planning by the animal. Identity-tuned sensory representations are categorical, invariant to nuances in the sensory stream and depend on associative learning. Although categorical representations are well documented across several sensory modalities, these tend to situate synaptically far from the sensory organs which reduces experimenter control over input-output transformations. The formation of such representations is a fundamental neural computation that remains poorly understood. Odor representations in the primary olfactory cortex have several characteristics that qualify them as categorical and identity-tuned, situated only two synapses away from the sensory epithelium. The formation of categorical representations is likely critically dependent on—and dynamically controlled by—recurrent circuitry within the primary olfactory cortex itself. Experiments suggest that the concerted activity of several neuromodulatory systems plays a decisive role in shaping categorical learning through complex interactions with recurrent activity and plasticity in primary olfactory cortex circuits. In this perspective we discuss missing pieces of the categorical learning puzzle, and why several features of olfaction make it an attractive model system for this challenge.
Collapse
|
23
|
Olfactory Evaluation in Alzheimer’s Disease Model Mice. Brain Sci 2022; 12:brainsci12050607. [PMID: 35624994 PMCID: PMC9139301 DOI: 10.3390/brainsci12050607] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 04/26/2022] [Accepted: 05/03/2022] [Indexed: 11/17/2022] Open
Abstract
Olfactory dysfunction is considered a pre-cognitive biomarker of Alzheimer’s disease (AD). Because the olfactory system is highly conserved across species, mouse models corresponding to various AD etiologies have been bred and used in numerous studies on olfactory disorders. The olfactory behavior test is a method required for early olfactory dysfunction detection in AD model mice. Here, we review the olfactory evaluation of AD model mice, focusing on traditional olfactory detection methods, olfactory behavior involving the olfactory cortex, and the results of olfactory behavior in AD model mice, aiming to provide some inspiration for further development of olfactory detection methods in AD model mice.
Collapse
|
24
|
Kim S, Nam Y, Kim HS, Jung H, Jeon SG, Hong SB, Moon M. Alteration of Neural Pathways and Its Implications in Alzheimer’s Disease. Biomedicines 2022; 10:biomedicines10040845. [PMID: 35453595 PMCID: PMC9025507 DOI: 10.3390/biomedicines10040845] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/29/2022] [Accepted: 03/31/2022] [Indexed: 02/01/2023] Open
Abstract
Alzheimer’s disease (AD) is a neurodegenerative disease accompanied by cognitive and behavioral symptoms. These AD-related manifestations result from the alteration of neural circuitry by aggregated forms of amyloid-β (Aβ) and hyperphosphorylated tau, which are neurotoxic. From a neuroscience perspective, identifying neural circuits that integrate various inputs and outputs to determine behaviors can provide insight into the principles of behavior. Therefore, it is crucial to understand the alterations in the neural circuits associated with AD-related behavioral and psychological symptoms. Interestingly, it is well known that the alteration of neural circuitry is prominent in the brains of patients with AD. Here, we selected specific regions in the AD brain that are associated with AD-related behavioral and psychological symptoms, and reviewed studies of healthy and altered efferent pathways to the target regions. Moreover, we propose that specific neural circuits that are altered in the AD brain can be potential targets for AD treatment. Furthermore, we provide therapeutic implications for targeting neuronal circuits through various therapeutic approaches and the appropriate timing of treatment for AD.
Collapse
Affiliation(s)
- Sujin Kim
- Department of Biochemistry, College of Medicine, Konyang University, 158, Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea; (S.K.); (Y.N.); (H.s.K.); (H.J.); (S.G.J.); (S.B.H.)
- Research Institute for Dementia Science, Konyang University, 158, Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea
| | - Yunkwon Nam
- Department of Biochemistry, College of Medicine, Konyang University, 158, Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea; (S.K.); (Y.N.); (H.s.K.); (H.J.); (S.G.J.); (S.B.H.)
| | - Hyeon soo Kim
- Department of Biochemistry, College of Medicine, Konyang University, 158, Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea; (S.K.); (Y.N.); (H.s.K.); (H.J.); (S.G.J.); (S.B.H.)
| | - Haram Jung
- Department of Biochemistry, College of Medicine, Konyang University, 158, Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea; (S.K.); (Y.N.); (H.s.K.); (H.J.); (S.G.J.); (S.B.H.)
| | - Seong Gak Jeon
- Department of Biochemistry, College of Medicine, Konyang University, 158, Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea; (S.K.); (Y.N.); (H.s.K.); (H.J.); (S.G.J.); (S.B.H.)
| | - Sang Bum Hong
- Department of Biochemistry, College of Medicine, Konyang University, 158, Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea; (S.K.); (Y.N.); (H.s.K.); (H.J.); (S.G.J.); (S.B.H.)
| | - Minho Moon
- Department of Biochemistry, College of Medicine, Konyang University, 158, Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea; (S.K.); (Y.N.); (H.s.K.); (H.J.); (S.G.J.); (S.B.H.)
- Research Institute for Dementia Science, Konyang University, 158, Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea
- Correspondence:
| |
Collapse
|
25
|
“Anosmia” the mysterious collateral damage of COVID-19. J Neurovirol 2022; 28:189-200. [PMID: 35249186 PMCID: PMC8898086 DOI: 10.1007/s13365-022-01060-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 10/01/2021] [Accepted: 02/01/2022] [Indexed: 12/24/2022]
Abstract
COVID-19 pandemic spreads worldwide, with more than 100 million positive cases and more than 2 million deaths. From the beginning of the COVID-19 pandemic, several otolaryngologists described many cases of a sudden loss of smell (anosmia) associated with the disease with or without additional symptoms. Anosmia is often the first and sometimes the only sign in the asymptomatic carriers of COVID-19. Still, this disorder is underestimated, and it is not life-threatening. However, it significantly decreases the quality of life. This olfactory dysfunction continues in several cases even after the nasopharyngeal swab was negative. The occurrence of anosmia can be used as a screening tool for COVID-19 patients and can be used to identify these patients to accomplish the isolation and tracking procedures. In this review, we highlighted the possible mechanisms of anosmia in COVID-19 patients, major pathologies and features of anosmia, implications of anosmia in early diagnosis of COVID-19, evaluation of the smell function during COVID-19, and management and treatment options of COVID-19 anosmia.
Collapse
|
26
|
Noto T, Zhou G, Yang Q, Lane G, Zelano C. Human Primary Olfactory Amygdala Subregions Form Distinct Functional Networks, Suggesting Distinct Olfactory Functions. Front Syst Neurosci 2021; 15:752320. [PMID: 34955769 PMCID: PMC8695617 DOI: 10.3389/fnsys.2021.752320] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 11/08/2021] [Indexed: 12/02/2022] Open
Abstract
Three subregions of the amygdala receive monosynaptic projections from the olfactory bulb, making them part of the primary olfactory cortex. These primary olfactory areas are located at the anterior-medial aspect of the amygdala and include the medial amygdala (MeA), cortical amygdala (CoA), and the periamygdaloid complex (PAC). The vast majority of research on the amygdala has focused on the larger basolateral and basomedial subregions, which are known to be involved in implicit learning, threat responses, and emotion. Fewer studies have focused on the MeA, CoA, and PAC, with most conducted in rodents. Therefore, our understanding of the functions of these amygdala subregions is limited, particularly in humans. Here, we first conducted a review of existing literature on the MeA, CoA, and PAC. We then used resting-state fMRI and unbiased k-means clustering techniques to show that the anatomical boundaries of human MeA, CoA, and PAC accurately parcellate based on their whole-brain resting connectivity patterns alone, suggesting that their functional networks are distinct, relative both to each other and to the amygdala subregions that do not receive input from the olfactory bulb. Finally, considering that distinct functional networks are suggestive of distinct functions, we examined the whole-brain resting network of each subregion and speculated on potential roles that each region may play in olfactory processing. Based on these analyses, we speculate that the MeA could potentially be involved in the generation of rapid motor responses to olfactory stimuli (including fight/flight), particularly in approach/avoid contexts. The CoA could potentially be involved in olfactory-related reward processing, including learning and memory of approach/avoid responses. The PAC could potentially be involved in the multisensory integration of olfactory information with other sensory systems. These speculations can be used to form the basis of future studies aimed at clarifying the olfactory functions of these under-studied primary olfactory areas.
Collapse
Affiliation(s)
- Torben Noto
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Guangyu Zhou
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Qiaohan Yang
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Gregory Lane
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Christina Zelano
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| |
Collapse
|
27
|
Yan Y, Aierken A, Wang C, Song D, Ni J, Wang Z, Quan Z, Qing H. A potential biomarker of preclinical Alzheimer's disease: The olfactory dysfunction and its pathogenesis-based neural circuitry impairments. Neurosci Biobehav Rev 2021; 132:857-869. [PMID: 34810025 DOI: 10.1016/j.neubiorev.2021.11.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 10/26/2021] [Accepted: 11/07/2021] [Indexed: 01/24/2023]
Abstract
The olfactory dysfunction can signal and act as a potential biomarker of preclinical AD. However, the precise regulatory mechanism of olfactory function on the neural pathogenesis of AD is still unclear. The impairment of neural networks in olfaction system has been shown to be tightly associated with AD. As key brain regions of the olfactory system, the olfactory bulb (OB) and the piriform cortex (PCx) have a profound influence on the olfactory function. Therefore, this review will explore the mechanism of olfactory dysfunction in preclinical AD in the perspective of abnormal neural networks in the OB and PCx and their associated brain regions, especially from two aspects of aberrant oscillations and synaptic plasticity damages, which help better understand the underlying mechanism of olfactory neural network damages related to AD.
Collapse
Affiliation(s)
- Yan Yan
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Ailikemu Aierken
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Chunjian Wang
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Da Song
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Junjun Ni
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Zhe Wang
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, The National Clinical Research Center for Geriatric Disease, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Zhenzhen Quan
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China.
| | - Hong Qing
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China.
| |
Collapse
|
28
|
Mouly AM, Bouillot C, Costes N, Zimmer L, Ravel N, Litaudon P. PET Metabolic Imaging of Time-Dependent Reorganization of Olfactory Cued Fear Memory Networks in Rats. Cereb Cortex 2021; 32:2717-2728. [PMID: 34668524 DOI: 10.1093/cercor/bhab376] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 09/15/2021] [Accepted: 09/16/2021] [Indexed: 12/24/2022] Open
Abstract
Memory consolidation involves reorganization at both the synaptic and system levels. The latter involves gradual reorganization of the brain regions that support memory and has been mostly highlighted using hippocampal-dependent tasks. The standard memory consolidation model posits that the hippocampus becomes gradually less important over time in favor of neocortical regions. In contrast, this reorganization of circuits in amygdala-dependent tasks has been less investigated. Moreover, this question has been addressed using primarily lesion or cellular imaging approaches thus precluding the comparison of recent and remote memory networks in the same animals. To overcome this limitation, we used microPET imaging to characterize, in the same animals, the networks activated during the recall of a recent versus remote memory in an olfactory cued fear conditioning paradigm. The data highlighted the drastic difference between the extents of the two networks. Indeed, although the recall of a recent odor fear memory activates a large network of structures spanning from the prefrontal cortex to the cerebellum, significant activations during remote memory retrieval are limited to the piriform cortex. These results strongly support the view that amygdala-dependent memories also undergo system-level reorganization, and that sensory cortical areas might participate in the long-term storage of emotional memories.
Collapse
Affiliation(s)
- Anne-Marie Mouly
- Lyon Neuroscience Research Center, CNRS UMR 5292, INSERM U1028, Université Claude Bernard Lyon 1, Bron Cedex 69675, France
| | | | | | - Luc Zimmer
- Lyon Neuroscience Research Center, CNRS UMR 5292, INSERM U1028, Université Claude Bernard Lyon 1, Bron Cedex 69675, France.,CERMEP-Life Imaging, Bron Cedex 69677, France.,Hospices Civils de Lyon, Lyon 69002, France
| | - Nadine Ravel
- Lyon Neuroscience Research Center, CNRS UMR 5292, INSERM U1028, Université Claude Bernard Lyon 1, Bron Cedex 69675, France
| | - Philippe Litaudon
- Lyon Neuroscience Research Center, CNRS UMR 5292, INSERM U1028, Université Claude Bernard Lyon 1, Bron Cedex 69675, France
| |
Collapse
|
29
|
Olfactory Optogenetics: Light Illuminates the Chemical Sensing Mechanisms of Biological Olfactory Systems. BIOSENSORS-BASEL 2021; 11:bios11090309. [PMID: 34562900 PMCID: PMC8470751 DOI: 10.3390/bios11090309] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 08/17/2021] [Accepted: 08/27/2021] [Indexed: 01/26/2023]
Abstract
The mammalian olfactory system has an amazing ability to distinguish thousands of odorant molecules at the trace level. Scientists have made great achievements on revealing the olfactory sensing mechanisms in decades; even though many issues need addressing. Optogenetics provides a novel technical approach to solve this dilemma by utilizing light to illuminate specific part of the olfactory system; which can be used in all corners of the olfactory system for revealing the olfactory mechanism. This article reviews the most recent advances in olfactory optogenetics devoted to elucidate the mechanisms of chemical sensing. It thus attempts to introduce olfactory optogenetics according to the structure of the olfactory system. It mainly includes the following aspects: the sensory input from the olfactory epithelium to the olfactory bulb; the influences of the olfactory bulb (OB) neuron activity patterns on olfactory perception; the regulation between the olfactory cortex and the olfactory bulb; and the neuromodulation participating in odor coding by dominating the olfactory bulb. Finally; current challenges and future development trends of olfactory optogenetics are proposed and discussed.
Collapse
|
30
|
|
31
|
Lunardi P, Mansk LMZ, Jaimes LF, Pereira GS. On the novel mechanisms for social memory and the emerging role of neurogenesis. Brain Res Bull 2021; 171:56-66. [PMID: 33753208 DOI: 10.1016/j.brainresbull.2021.03.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 02/24/2021] [Accepted: 03/08/2021] [Indexed: 01/25/2023]
Abstract
Social memory (SM) is a key element in social cognition and it encompasses the neural representation of conspecifics, an essential information to guide behavior in a social context. Here we evaluate classical and cutting-edge studies on neurobiology of SM, using as a guiding principle behavioral tasks performed in adult rodents. Our review highlights the relevance of the hippocampus, especially the CA2 region, as a neural substrate for SM and suggest that neural ensembles in the olfactory bulb may also encode SM traces. Compared to other hippocampus-dependent memories, much remains to be done to describe the neurobiological foundations of SM. Nonetheless, we argue that special attention should be paid to neurogenesis. Finally, we pinpoint the remaining open question on whether the hippocampal adult neurogenesis acts through pattern separation to permit the discrimination of highly similar stimuli during behavior.
Collapse
Affiliation(s)
- Paula Lunardi
- Núcleo de Neurociências, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Lara M Z Mansk
- Núcleo de Neurociências, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Laura F Jaimes
- Núcleo de Neurociências, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Grace S Pereira
- Núcleo de Neurociências, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
| |
Collapse
|
32
|
Brain Metabolic Correlates of Persistent Olfactory Dysfunction after SARS-Cov2 Infection. Biomedicines 2021; 9:biomedicines9030287. [PMID: 33808956 PMCID: PMC7998481 DOI: 10.3390/biomedicines9030287] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 03/04/2021] [Accepted: 03/09/2021] [Indexed: 12/20/2022] Open
Abstract
We aimed to evaluate the brain hypometabolic signature of persistent isolated olfactory dysfunction after SARS-CoV-2 infection. Twenty-two patients underwent whole-body [18F]-FDG PET, including a dedicated brain acquisition at our institution between May and December 2020 following their recovery after SARS-Cov2 infection. Fourteen of these patients presented isolated persistent hyposmia (smell diskettes olfaction test was used). A voxel-wise analysis (using Statistical Parametric Mapping software version 8 (SPM8)) was performed to identify brain regions of relative hypometabolism in patients with hyposmia with respect to controls. Structural connectivity of these regions was assessed (BCB toolkit). Relative hypometabolism was demonstrated in bilateral parahippocampal and fusiform gyri and in left insula in patients with respect to controls. Structural connectivity maps highlighted the involvement of bilateral longitudinal fasciculi. This study provides evidence of cortical hypometabolism in patients with isolated persistent hyposmia after SARS-Cov2 infection. [18F]-FDG PET may play a role in the identification of long-term brain functional sequelae of COVID-19.
Collapse
|
33
|
Zhou G, Olofsson JK, Koubeissi MZ, Menelaou G, Rosenow J, Schuele SU, Xu P, Voss JL, Lane G, Zelano C. Human hippocampal connectivity is stronger in olfaction than other sensory systems. Prog Neurobiol 2021; 201:102027. [PMID: 33640412 DOI: 10.1016/j.pneurobio.2021.102027] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 01/20/2021] [Accepted: 02/21/2021] [Indexed: 12/17/2022]
Abstract
During mammalian evolution, primate neocortex expanded, shifting hippocampal functional networks away from primary sensory cortices, towards association cortices. Reflecting this rerouting, human resting hippocampal functional networks preferentially include higher association cortices, while those in rodents retained primary sensory cortices. Research on human visual, auditory and somatosensory systems shows evidence of this rerouting. Olfaction, however, is unique among sensory systems in its relative structural conservation throughout mammalian evolution, and it is unknown whether human primary olfactory cortex was subject to the same rerouting. We combined functional neuroimaging and intracranial electrophysiology to directly compare hippocampal functional networks across human sensory systems. We show that human primary olfactory cortex-including the anterior olfactory nucleus, olfactory tubercle and piriform cortex-has stronger functional connectivity with hippocampal networks at rest, compared to other sensory systems. This suggests that unlike other sensory systems, olfactory-hippocampal connectivity may have been retained in mammalian evolution. We further show that olfactory-hippocampal connectivity oscillates with nasal breathing. Our findings suggest olfaction might provide insight into how memory and cognition depend on hippocampal interactions.
Collapse
Affiliation(s)
- Guangyu Zhou
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
| | - Jonas K Olofsson
- Department of Psychology, Stockholm University, Stockholm, Sweden; Emotional Brain Institute, Nathan S. Kline Institute, Orangeburg, NY, USA; Department of Child and Adolescent Psychiatry, New York University School of Medicine, New York, NY, USA
| | | | | | - Joshua Rosenow
- Department of Neurosurgery, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Stephan U Schuele
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Pengfei Xu
- Beijing Key Laboratory of Applied Experimental Psychology, Faculty of Psychology, Beijing Normal University, Beijing, China; Center for Neuroimaging, Shenzhen Institute of Neuroscience, Shenzhen, China; Guangdong-Hong Kong-Macao Greater Bay Area Research Institute for Neuroscience and Neurotechnologies, Kwun Tong, Hong Kong, China
| | - Joel L Voss
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA; Department of Medical Social Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, USA; Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Gregory Lane
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Christina Zelano
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
| |
Collapse
|
34
|
Hartig R, Wolf D, Schmeisser MJ, Kelsch W. Genetic influences of autism candidate genes on circuit wiring and olfactory decoding. Cell Tissue Res 2021; 383:581-595. [PMID: 33515293 PMCID: PMC7872953 DOI: 10.1007/s00441-020-03390-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 12/10/2020] [Indexed: 12/24/2022]
Abstract
Olfaction supports a multitude of behaviors vital for social communication and interactions between conspecifics. Intact sensory processing is contingent upon proper circuit wiring. Disturbances in genetic factors controlling circuit assembly and synaptic wiring can lead to neurodevelopmental disorders, such as autism spectrum disorder (ASD), where impaired social interactions and communication are core symptoms. The variability in behavioral phenotype expression is also contingent upon the role environmental factors play in defining genetic expression. Considering the prevailing clinical diagnosis of ASD, research on therapeutic targets for autism is essential. Behavioral impairments may be identified along a range of increasingly complex social tasks. Hence, the assessment of social behavior and communication is progressing towards more ethologically relevant tasks. Garnering a more accurate understanding of social processing deficits in the sensory domain may greatly contribute to the development of therapeutic targets. With that framework, studies have found a viable link between social behaviors, circuit wiring, and altered neuronal coding related to the processing of salient social stimuli. Here, the relationship between social odor processing in rodents and humans is examined in the context of health and ASD, with special consideration for how genetic expression and neuronal connectivity may regulate behavioral phenotypes.
Collapse
Affiliation(s)
- Renée Hartig
- Department of Psychiatry & Psychotherapy, University Medical Center, Johannes Gutenberg-University, 55131, Mainz, Germany.,Focus Program Translational Neurosciences (FTN), University Medical Center, Johannes Gutenberg-University, 55131, Mainz, Germany.,Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, 68159, Mannheim, Germany.,Institute for Microscopic Anatomy and Neurobiology, University Medical Center, Johannes Gutenberg-University, 55131, Mainz, Germany
| | - David Wolf
- Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, 68159, Mannheim, Germany
| | - Michael J Schmeisser
- Focus Program Translational Neurosciences (FTN), University Medical Center, Johannes Gutenberg-University, 55131, Mainz, Germany.,Institute for Microscopic Anatomy and Neurobiology, University Medical Center, Johannes Gutenberg-University, 55131, Mainz, Germany
| | - Wolfgang Kelsch
- Department of Psychiatry & Psychotherapy, University Medical Center, Johannes Gutenberg-University, 55131, Mainz, Germany. .,Focus Program Translational Neurosciences (FTN), University Medical Center, Johannes Gutenberg-University, 55131, Mainz, Germany. .,Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, 68159, Mannheim, Germany.
| |
Collapse
|
35
|
Brunert D, Rothermel M. Extrinsic neuromodulation in the rodent olfactory bulb. Cell Tissue Res 2021; 383:507-524. [PMID: 33355709 PMCID: PMC7873007 DOI: 10.1007/s00441-020-03365-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 11/24/2020] [Indexed: 12/16/2022]
Abstract
Evolutionarily, olfaction is one of the oldest senses and pivotal for an individual's health and survival. The olfactory bulb (OB), as the first olfactory relay station in the brain, is known to heavily process sensory information. To adapt to an animal's needs, OB activity can be influenced by many factors either from within (intrinsic neuromodulation) or outside (extrinsic neuromodulation) the OB which include neurotransmitters, neuromodulators, hormones, and neuropeptides. Extrinsic sources seem to be of special importance as the OB receives massive efferent input from numerous brain centers even outweighing the sensory input from the nose. Here, we review neuromodulatory processes in the rodent OB from such extrinsic sources. We will discuss extrinsic neuromodulation according to points of origin, receptors involved, affected circuits, and changes in behavior. In the end, we give a brief outlook on potential future directions in research on neuromodulation in the OB.
Collapse
Affiliation(s)
- Daniela Brunert
- Department of Chemosensation, AG Neuromodulation, Institute for Biology II, RWTH Aachen University, 52074, Aachen, Germany
| | - Markus Rothermel
- Department of Chemosensation, AG Neuromodulation, Institute for Biology II, RWTH Aachen University, 52074, Aachen, Germany.
| |
Collapse
|
36
|
O'Reilly JA, Conway BA. Classical and controlled auditory mismatch responses to multiple physical deviances in anaesthetised and conscious mice. Eur J Neurosci 2020; 53:1839-1854. [DOI: 10.1111/ejn.15072] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 11/16/2020] [Accepted: 11/26/2020] [Indexed: 12/24/2022]
Affiliation(s)
- Jamie A. O'Reilly
- College of Biomedical Engineering Rangsit University Pathum Thani Thailand
| | - Bernard A. Conway
- Department of Biomedical Engineering University of Strathclyde Glasgow UK
| |
Collapse
|
37
|
Hwang BY, Mampre D, Penn R, Anderson WS, Kang J, Kamath V. Olfactory Testing in Temporal Lobe Epilepsy: a Systematic Review. Curr Neurol Neurosci Rep 2020; 20:65. [PMID: 33169232 DOI: 10.1007/s11910-020-01083-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/24/2020] [Indexed: 12/23/2022]
Abstract
PURPOSE OF REVIEW Olfactory testing is a potentially safe, cost-effective, bedside evaluation tool for diagnosis, monitoring, and risk assessment for surgery in temporal lobe epilepsy (TLE) patients, but testing methods and relevant olfactory domains are not standardized. We conducted a systematic review to evaluate olfactory tests in TLE and summarize the results of the literature. RECENT FINDINGS Olfactory tests varied significantly in odorant administration tools and devices, target odorants, evaluation timing, and grading scales. The Smell Threshold Test and University of Pennsylvania Smell Identification Test were the most validated single-domain tests for odor detection and odor identification, respectively. For multi-domain tests, Odor Memory/Discrimination Test and the Sniffin' Sticks test were the most validated. Results of olfactory tests in TLE are presented by domain. Rigorous validation, standardization, and comparative analysis of existing olfactory tests by domain is urgently needed to establish the utility and efficacy of olfactory testing in TLE.
Collapse
Affiliation(s)
- Brian Y Hwang
- Division of Functional Neurosurgery, Department of Neurosurgery, Johns Hopkins School of Medicine, 600 N. Wolfe Street, Meyer 8-181, Baltimore, MD, 21287, USA.
| | - David Mampre
- Division of Functional Neurosurgery, Department of Neurosurgery, Johns Hopkins School of Medicine, 600 N. Wolfe Street, Meyer 8-181, Baltimore, MD, 21287, USA
| | - Rachel Penn
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - William S Anderson
- Division of Functional Neurosurgery, Department of Neurosurgery, Johns Hopkins School of Medicine, 600 N. Wolfe Street, Meyer 8-181, Baltimore, MD, 21287, USA
| | - Joon Kang
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Vidyulata Kamath
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD, USA
| |
Collapse
|
38
|
Cleland TA, Borthakur A. A Systematic Framework for Olfactory Bulb Signal Transformations. Front Comput Neurosci 2020; 14:579143. [PMID: 33071767 PMCID: PMC7538604 DOI: 10.3389/fncom.2020.579143] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 08/17/2020] [Indexed: 11/13/2022] Open
Abstract
We describe an integrated theory of olfactory systems operation that incorporates experimental findings across scales, stages, and methods of analysis into a common framework. In particular, we consider the multiple stages of olfactory signal processing as a collective system, in which each stage samples selectively from its antecedents. We propose that, following the signal conditioning operations of the nasal epithelium and glomerular-layer circuitry, the plastic external plexiform layer of the olfactory bulb effects a process of category learning-the basis for extracting meaningful, quasi-discrete odor representations from the metric space of undifferentiated olfactory quality. Moreover, this early categorization process also resolves the foundational problem of how odors of interest can be recognized in the presence of strong competitive interference from simultaneously encountered background odorants. This problem is fundamentally constraining on early-stage olfactory encoding strategies and must be resolved if these strategies and their underlying mechanisms are to be understood. Multiscale general theories of olfactory systems operation are essential in order to leverage the analytical advantages of engineered approaches together with our expanding capacity to interrogate biological systems.
Collapse
Affiliation(s)
- Thomas A. Cleland
- Computational Physiology Laboratory, Department of Psychology, Cornell University, Ithaca, NY, United States
| | - Ayon Borthakur
- Computational Physiology Laboratory, Field of Computational Biology, Cornell University, Ithaca, NY, United States
| |
Collapse
|
39
|
Dynamic Impairment of Olfactory Behavior and Signaling Mediated by an Olfactory Corticofugal System. J Neurosci 2020; 40:7269-7285. [PMID: 32817250 DOI: 10.1523/jneurosci.2667-19.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Revised: 06/30/2020] [Accepted: 07/05/2020] [Indexed: 01/16/2023] Open
Abstract
Processing of olfactory information is modulated by centrifugal projections from cortical areas, yet their behavioral relevance and underlying neural mechanisms remain unclear in most cases. The anterior olfactory nucleus (AON) is part of the olfactory cortex, and its extensive connections to multiple upstream and downstream brain centers place it in a prime position to modulate early sensory information in the olfactory system. Here, we show that optogenetic activation of AON neurons in awake male and female mice was not perceived as an odorant equivalent cue. However, AON activation during odorant presentation reliably suppressed behavioral odor responses. This AON-mediated effect was fast and constant across odors and concentrations. Likewise, activation of glutamatergic AON projections to the olfactory bulb (OB) transiently inhibited the excitability of mitral/tufted cells (MTCs) that relay olfactory input to the cortex. Single-unit MTC recordings revealed that optogenetic activation of glutamatergic AON terminals in the OB transiently decreased sensory-evoked MTC spiking, regardless of the strength or polarity of the sensory response. The reduction in MTC firing during optogenetic stimulation was confirmed in recordings in awake mice. These findings suggest that glutamatergic AON projections to the OB impede early olfactory signaling by inhibiting OB output neurons, thereby dynamically gating sensory throughput to the cortex.SIGNIFICANCE STATEMENT The anterior olfactory nucleus (AON) as an olfactory information processing area sends extensive projections to multiple brain centers, but the behavioral consequences of its activation have been scarcely investigated. Using behavioral tests in combination with optogenetic manipulation, we show that, in contrast to what has been suggested previously, the AON does not seem to form odor percepts but instead suppresses behavioral odor responses across odorants and concentrations. Furthermore, this study shows that AON activation inhibits olfactory bulb output neurons in both anesthetized as well as awake mice, pointing to a potential mechanism by which the olfactory cortex can actively and dynamically gate sensory throughput to higher brain centers.
Collapse
|
40
|
Han AY, Mukdad L, Long JL, Lopez IA. Anosmia in COVID-19: Mechanisms and Significance. Chem Senses 2020; 45:bjaa040. [PMID: 32556089 PMCID: PMC7449368 DOI: 10.1093/chemse/bjaa040] [Citation(s) in RCA: 82] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Indexed: 12/13/2022] Open
Abstract
The global pandemic of coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 remains a challenge for prevention due to asymptomatic or paucisymptomatic patients. Anecdotal and preliminary evidence from multiple institutions shows that these patients present with a sudden onset of anosmia without rhinitis. We aim to review the pathophysiology of anosmia related to viral upper respiratory infections and the prognostic implications. Current evidence suggests that SARS-CoV-2-related anosmia may be a new viral syndrome specific to COVID-19 and can be mediated by intranasal inoculation of SARS-CoV-2 into the olfactory neural circuitry. The clinical course of neuroinvasion of SARS-CoV-2 is yet unclear, however an extended follow up of these patients to assess for neurological sequelae including encephalitis, cerebrovascular accidents and long-term neurodegenerative risk may be indicated.
Collapse
Affiliation(s)
- Albert Y Han
- Department of Head and Neck Surgery, University of California, Los Angeles, Rehabilitation Center 35–64, Los Angeles, CA, USA
| | - Laith Mukdad
- Department of Head and Neck Surgery, University of California, Los Angeles, Rehabilitation Center 35–64, Los Angeles, CA, USA
| | - Jennifer L Long
- Department of Head and Neck Surgery, University of California, Los Angeles, Rehabilitation Center 35–64, Los Angeles, CA, USA
- Greater Los Angeles VA Healthcare System, Los Angeles, CA, USA
| | - Ivan A Lopez
- Department of Head and Neck Surgery, University of California, Los Angeles, Rehabilitation Center 35–64, Los Angeles, CA, USA
| |
Collapse
|