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Audronyte E, Sutnikiene V, Pakulaite-Kazliene G, Kaubrys G. Olfactory memory in mild cognitive impairment and Alzheimer's disease. Front Neurol 2023; 14:1165594. [PMID: 37332995 PMCID: PMC10272592 DOI: 10.3389/fneur.2023.1165594] [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: 02/14/2023] [Accepted: 05/15/2023] [Indexed: 06/20/2023] Open
Abstract
Introduction Olfaction is impaired in Alzheimer's disease (AD). However, olfactory memory has rarely been examined. As the pathogenesis of AD remains largely unknown, collecting more data regarding the occurrence and progression of its symptoms would help gain more insight into the disease. Objective To investigate olfactory memory and its relationship with verbal memory and other clinical features in patients with early-stage AD. Methods Three groups of participants were enrolled in this study: patients with mild dementia due to AD (MD-AD, N = 30), patients with mild cognitive impairment due to AD (MCI-AD, N = 30), and cognitively normal older participants (CN, N = 30). All participants underwent cognitive evaluation (Clinical Dementia Rating scale, Mini Mental State Examination, Alzheimer's Disease Assessment Scale-Cognitive Subscale, delayed verbal recall, and verbal fluency tests) and assessment of olfactory immediate and delayed recognition memory. Results Olfactory immediate and delayed recognition memory scores were significantly lower in the MD-AD group than in the MCI-AD and CN groups. The MCI-AD and CN groups did not differ significantly [in both cases, Kruskal-Wallis test, p < 0.05; post hoc analysis revealed significant differences between the MD-AD and MCI-AD groups and between the MD-AD and CN groups (p < 0.05), and no significant difference between the MCI-AD and CN groups (p > 0.05)]. Verbal immediate recall, delayed recall after 5 min, and delayed recall after 30 min scores were significantly worse in the MD-AD and MCI-AD groups than in the CN group. MD-AD and MCI-AD groups did not differ significantly [in all cases Kruskal-Wallis test, p < 0.05; post hoc analysis revealed significant differences between MD-AD and CN groups, and MCI-AD and CN groups (p < 0.05) and no significant difference between MD-AD and MCI-AD groups (p > 0.05)]. Duration of AD symptoms was a strong predictor of both immediate and delayed olfactory recognition memory scores. Conclusion Olfactory memory impairment was observed in patients with AD. The changes progress during the course of the disease. However, unlike verbal memory, olfactory memory is not significantly impaired in the prodromal stage of AD.
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Swanson JL, Ortiz-Guzman J, Srivastava S, Chin PS, Dooling SW, Hanson Moss E, Kochukov MY, Hunt PJ, Patel JM, Pekarek BT, Tong Q, Arenkiel BR. Activation of basal forebrain-to-lateral habenula circuitry drives reflexive aversion and suppresses feeding behavior. Sci Rep 2022; 12:22044. [PMID: 36543829 PMCID: PMC9772215 DOI: 10.1038/s41598-022-26306-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 12/13/2022] [Indexed: 12/24/2022] Open
Abstract
Environmental cues and internal states such as mood, reward, or aversion directly influence feeding behaviors beyond homeostatic necessity. The hypothalamus has been extensively investigated for its role in homeostatic feeding. However, many of the neural circuits that drive more complex, non-homeostatic feeding that integrate valence and sensory cues (such as taste and smell) remain unknown. Here, we describe a basal forebrain (BF)-to-lateral habenula (LHb) circuit that directly modulates non-homeostatic feeding behavior. Using viral-mediated circuit mapping, we identified a population of glutamatergic neurons within the BF that project to the LHb, which responds to diverse sensory cues, including aversive and food-related odors. Optogenetic activation of BF-to-LHb circuitry drives robust, reflexive-like aversion. Furthermore, activation of this circuitry suppresses the drive to eat in a fasted state. Together, these data reveal a role of basal forebrain glutamatergic neurons in modulating LHb-associated aversion and feeding behaviors by sensing environmental cues.
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Affiliation(s)
- Jessica L Swanson
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Joshua Ortiz-Guzman
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Snigdha Srivastava
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
- Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, USA
| | - Pey-Shyuan Chin
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Sean W Dooling
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Elizabeth Hanson Moss
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Mikhail Y Kochukov
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Patrick J Hunt
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
- Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, USA
| | - Jay M Patel
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
- Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Brandon T Pekarek
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Qingchun Tong
- Center for Metabolic and Degenerative Disease, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Benjamin R Arenkiel
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA.
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA.
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Huang L, Zhang W, Han Y, Tang Y, Zhou W, Liu G, Shi W. Anti-Depressant Fluoxetine Hampers Olfaction of Goldfish by Interfering with the Initiation, Transmission, and Processing of Olfactory Signals. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:15848-15859. [PMID: 36260920 DOI: 10.1021/acs.est.2c02987] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The ubiquitous presence of fluoxetine (FLX) in aquatic environments poses great threat to fish species. However, little is known about its deleterious impacts on fish olfaction. In this study, the olfactory toxicity of FLX at environmentally realistic levels was assessed by monitoring the behavioral and electroolfactogram (EOG) responses to olfactory stimuli with goldfish (Carassius auratus), and the toxification mechanisms underlying the observed olfaction dysfunction were also investigated. Our results showed that the behavioral and EOG responses of goldfish to olfactory stimuli were significantly weakened by FLX, indicating an evident toxicity of FLX to olfaction. Moreover, FLX exposure led to significant alterations in olfactory initiation-related genes, suppression of ion pumps (Ca2+-ATPase and Na+/K+-ATPase), tissue lesions, and fewer olfactory sensory neurons in olfactory epithelium. In addition to altering the expression of olfactory transmission-related genes, comparative metabolomic analysis found that olfaction-related neurotransmitters (i.e., l-glutamate and acetylcholine) and the olfactory transduction pathway were significantly affected by FLX. Furthermore, evident tissue lesions, aggravated lipid peroxidation and apoptosis, and less neuropeptide Y were observed in the olfactory bulbs of FLX-exposed goldfish. Our findings indicate that FLX may hamper goldfish olfaction by interfering with the initiation, transmission, and processing of olfactory signals.
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Affiliation(s)
- Lin Huang
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, P. R. China
| | - Weixia Zhang
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, P. R. China
| | - Yu Han
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, P. R. China
| | - Yu Tang
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, P. R. China
| | - Weishang Zhou
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, P. R. China
| | - Guangxu Liu
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, P. R. China
| | - Wei Shi
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, P. R. China
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Characterization of social behavior in young and middle-aged ChAT-IRES-Cre mouse. PLoS One 2022; 17:e0272141. [PMID: 35925937 PMCID: PMC9352053 DOI: 10.1371/journal.pone.0272141] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 07/13/2022] [Indexed: 11/19/2022] Open
Abstract
The cholinergic system is an important modulator of brain processes. It contributes to the regulation of several cognitive functions and emotional states, hence altering behaviors. Previous works showed that cholinergic (nicotinic) receptors of the prefrontal cortex are needed for adapted social behaviors. However, these data were obtained in mutant mice that also present alterations of several neurotransmitter systems, in addition to the cholinergic system. ChAT-IRES-Cre mice, that express the Cre recombinase specifically in cholinergic neurons, are useful tools to investigate the role of the cholinergic circuits in behavior. However, their own behavioral phenotype has not yet been fully characterized, in particular social behavior. In addition, the consequences of aging on the cholinergic system of ChAT-IRES-Cre mice has never been studied, despite the fact that aging is known to compromise the cholinergic system efficiency. The aim of the current study was thus to characterize the social phenotype of ChAT-IRES-Cre mice both at young (2–3 months) and middle (10–11 months) ages. Our results reveal an alteration of the cholinergic system, evidenced by a decrease of ChAT, CHT and VAChT gene expression in the striatum of the mice, that was accompanied by mild social disturbances and a tendency towards anxiety. Aging decreased social dominance, without being amplified by the cholinergic alterations. Altogether, this study shows that ChAT-IRES-Cre mice are useful models for studying the cholinergic system‘s role in social behavior using appropriate modulating technics (optogenetic or DREADD).
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De Saint Jan D. Target-specific control of olfactory bulb periglomerular cells by GABAergic and cholinergic basal forebrain inputs. eLife 2022; 11:71965. [PMID: 35225232 PMCID: PMC8901171 DOI: 10.7554/elife.71965] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 02/16/2022] [Indexed: 11/13/2022] Open
Abstract
The olfactory bulb (OB), the first relay for odor processing in the brain, receives dense GABAergic and cholinergic long-range projections from basal forebrain (BF) nuclei that provide information about the internal state and behavioral context of the animal. However, the targets, impact, and dynamic of these afferents are still unclear. How BF synaptic inputs modulate activity in diverse subtypes of periglomerular (PG) interneurons using optogenetic stimulation and loose cell-attached or whole-cell patch-clamp recording in OB slices from adult mice were studied in this article. GABAergic BF inputs potently blocked PG cells firing except in a minority of calretinin-expressing cells in which GABA release elicited spiking. Parallel cholinergic projections excited a previously overlooked PG cell subtype via synaptic activation of M1 muscarinic receptors. Low-frequency stimulation of the cholinergic axons drove persistent firing in these PG cells, thereby increasing tonic inhibition in principal neurons. Taken together, these findings suggest that modality-specific BF inputs can orchestrate synaptic inhibition in OB glomeruli using multiple, potentially independent, inhibitory or excitatory target-specific pathways.
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Affiliation(s)
- Didier De Saint Jan
- Institut des Neurosciences Cellulaires et Intégratives, Centre National de la Recherche Scientifique, Strasbourg, France
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6
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Ahnaou A, Chave L, Manyakov NV, Drinkenburg WHIM. Odour Retrieval Processing in Mice: Cholinergic Modulation of Oscillatory Coupling in Olfactory Bulb-Piriform Networks. Neuropsychobiology 2022; 80:374-392. [PMID: 33588406 DOI: 10.1159/000513511] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 11/26/2020] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIMS Olfactory dysfunction can provide valuable insight into early pathophysiological processes of brain disorders. Olfactory processing of chemosensory and odour sensitivity relies on segregating salient odours from background odours cues. Odour-evoked fast oscillations in the olfactory bulb (OB) are hypothesized to be an important index of odour quality coding. The present preclinical work aimed at better understanding connectivity associated with odour coding and behavioural odour discrimination. METHODS Network oscillations and functional connectivity (FC) were measured in C57BL/6 mice performing the olfactory associative odour learning (OL) test, using multichannel local field potential recordings in key olfactory networks. Cholinergic modulation of odour processing was investigated using the muscarinic antagonist scopolamine. RESULTS At the behavioural level, olfactory memory, which refers to the acquisition and recollection of a reference odour by reduced exploration time, was observed in animals that correctly learned the task. Significant decrease in mean investigation and retrieval time of the associated odour-food reward was observed between trials. At the network level, the associated odour during sniffing behaviour was associated with enhanced coherence in the β and γ frequency oscillations across the olfactory pathway, with marked changes observed between the OB and anterior piriform cortex (PC). The enhanced phase-amplitude cross-frequency coupling in the OB and the weak coupling index in the hippocampal CA1 suggests a role of the OB network in olfaction encoding and processing. Scopolamine impaired behavioural and FC underlying recall and retrieval of the associated odour. CONCLUSION The results suggest that the acquisition and formation of odour reference memory rely primarily on FC at the OB-PC network and confirm the role of muscarinic receptors in olfactory retrieval processing.
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Affiliation(s)
- Abdallah Ahnaou
- Department of Neuroscience, Janssen Research & Development, a Division of Janssen Pharmaceutica NV, Beerse, Belgium,
| | - Lucile Chave
- Department of Neuroscience, Janssen Research & Development, a Division of Janssen Pharmaceutica NV, Beerse, Belgium
| | - Nikolay V Manyakov
- Department of Neuroscience, Janssen Research & Development, a Division of Janssen Pharmaceutica NV, Beerse, Belgium
| | - Wilhelmus H I M Drinkenburg
- Department of Neuroscience, Janssen Research & Development, a Division of Janssen Pharmaceutica NV, Beerse, Belgium
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Barrett MJ, Murphy JM, Zhang J, Blair JC, Flanigan JL, Nawaz H, Dalrymple WA, Sperling SA, Patrie J, Druzgal TJ. Olfaction, cholinergic basal forebrain degeneration, and cognition in early Parkinson disease. Parkinsonism Relat Disord 2021; 90:27-32. [PMID: 34348192 DOI: 10.1016/j.parkreldis.2021.07.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 07/23/2021] [Accepted: 07/23/2021] [Indexed: 12/21/2022]
Abstract
INTRODUCTION Impaired olfaction and reduced cholinergic nucleus 4 (Ch4) volume both predict greater cognitive decline in Parkinson's disease (PD). We examined the relationship between olfaction, longitudinal change in cholinergic basal forebrain nuclei and their target regions, and cognition in early PD. METHODS We analyzed a cohort of 97 PD participants from the Parkinson's Progression Markers Initiative with brain MRIs at baseline, 1 year, 2 years, and 4 years. Using probabilistic maps, regional grey matter density (GMD) was calculated for Ch4, cholinergic nuclei 1, 2, and 3 (Ch123), and their target regions. RESULTS Baseline University of Pennsylvania Smell Identification Test score correlated with change in GMD of all regions of interest (all p < 0.05). Rate of change of Ch4 GMD was correlated with rate of change of Ch123 (p = 0.034), cortex (p = 0.001), and amygdala GMD (p < 0.001), but not hippocampus GMD (p = 0.38). Rate of change of Ch123 GMD was correlated with rate of change of cortex (p = 0.001) and hippocampus (p < 0.001), but not amygdala GMD (p = 0.133). In a linear regression model including change in GMD of all regions of interest and age as predictors, change in cortex GMD (βˆslope= 38.2; 95 % CI: [0.47, 75.9]) and change in hippocampus GMD (βˆslope= 24.8; 95 % CI: [0.80, 48.8]) were significant predictors of Montreal Cognitive Assessment score change over time. CONCLUSION Impaired olfaction is associated with degeneration of the cholinergic basal forebrain and bilateral cortex, amygdala, and hippocampus in PD. The relationship between impaired olfaction and cognitive decline may be mediated by greater atrophy of the cortex and hippocampus.
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Affiliation(s)
- Matthew J Barrett
- Department of Neurology, Virginia Commonwealth University, Richmond, VA, USA.
| | - Justin M Murphy
- School of Medicine, University of Virginia, Charlottesville, VA, USA
| | - Jeffrey Zhang
- School of Medicine, University of Virginia, Charlottesville, VA, USA
| | - Jamie C Blair
- Department of Radiology and Medical Imaging, Division of Neuroradiology, University of Virginia Health System, Charlottesville, VA, USA
| | - Joseph L Flanigan
- Department of Neurology, University of Virginia, Charlottesville, VA, USA
| | - Huma Nawaz
- Department of Neurology, Virginia Commonwealth University, Richmond, VA, USA
| | - W Alex Dalrymple
- Department of Neurology, University of Virginia, Charlottesville, VA, USA
| | - Scott A Sperling
- Department of Neurology, University of Virginia, Charlottesville, VA, USA
| | - James Patrie
- Department of Public Health Sciences, University of Virginia, Charlottesville, VA, USA
| | - T Jason Druzgal
- Department of Radiology and Medical Imaging, Division of Neuroradiology, University of Virginia Health System, Charlottesville, VA, USA
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Huang Z, Tatti R, Loeven AM, Landi Conde DR, Fadool DA. Modulation of Neural Microcircuits That Control Complex Dynamics in Olfactory Networks. Front Cell Neurosci 2021; 15:662184. [PMID: 34239417 PMCID: PMC8259627 DOI: 10.3389/fncel.2021.662184] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 05/10/2021] [Indexed: 11/13/2022] Open
Abstract
Neuromodulation influences neuronal processing, conferring neuronal circuits the flexibility to integrate sensory inputs with behavioral states and the ability to adapt to a continuously changing environment. In this original research report, we broadly discuss the basis of neuromodulation that is known to regulate intrinsic firing activity, synaptic communication, and voltage-dependent channels in the olfactory bulb. Because the olfactory system is positioned to integrate sensory inputs with information regarding the internal chemical and behavioral state of an animal, how olfactory information is modulated provides flexibility in coding and behavioral output. Herein we discuss how neuronal microcircuits control complex dynamics of the olfactory networks by homing in on a special class of local interneurons as an example. While receptors for neuromodulation and metabolic peptides are widely expressed in the olfactory circuitry, centrifugal serotonergic and cholinergic inputs modulate glomerular activity and are involved in odor investigation and odor-dependent learning. Little is known about how metabolic peptides and neuromodulators control specific neuronal subpopulations. There is a microcircuit between mitral cells and interneurons that is comprised of deep-short-axon cells in the granule cell layer. These local interneurons express pre-pro-glucagon (PPG) and regulate mitral cell activity, but it is unknown what initiates this type of regulation. Our study investigates the means by which PPG neurons could be recruited by classical neuromodulators and hormonal peptides. We found that two gut hormones, leptin and cholecystokinin, differentially modulate PPG neurons. Cholecystokinin reduces or increases spike frequency, suggesting a heterogeneous signaling pathway in different PPG neurons, while leptin does not affect PPG neuronal firing. Acetylcholine modulates PPG neurons by increasing the spike frequency and eliciting bursts of action potentials, while serotonin does not affect PPG neuron excitability. The mechanisms behind this diverse modulation are not known, however, these results clearly indicate a complex interplay of metabolic signaling molecules and neuromodulators that may fine-tune neuronal microcircuits.
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Affiliation(s)
- Zhenbo Huang
- Program in Neuroscience, Florida State University, Tallahassee, FL, United States
| | - Roberta Tatti
- Program in Neuroscience, Florida State University, Tallahassee, FL, United States
| | - Ashley M Loeven
- Cell and Molecular Biology Program, Department of Biological Science, Florida State University, Tallahassee, FL, United States
| | - Daniel R Landi Conde
- Program in Neuroscience, Florida State University, Tallahassee, FL, United States
| | - Debra Ann Fadool
- Program in Neuroscience, Florida State University, Tallahassee, FL, United States.,Cell and Molecular Biology Program, Department of Biological Science, Florida State University, Tallahassee, FL, United States.,Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, United States
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Bang Y, Lim J, Choi HJ. Recent advances in the pathology of prodromal non-motor symptoms olfactory deficit and depression in Parkinson's disease: clues to early diagnosis and effective treatment. Arch Pharm Res 2021; 44:588-604. [PMID: 34145553 PMCID: PMC8254697 DOI: 10.1007/s12272-021-01337-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 06/01/2021] [Indexed: 12/14/2022]
Abstract
Parkinson’s disease (PD) is a progressive neurodegenerative disease characterized by movement dysfunction due to selective degeneration of dopaminergic neurons in the substantia nigra pars compacta. Non-motor symptoms of PD (e.g., sensory dysfunction, sleep disturbance, constipation, neuropsychiatric symptoms) precede motor symptoms, appear at all stages, and impact the quality of life, but they frequently go unrecognized and remain untreated. Even when identified, traditional dopamine replacement therapies have little effect. We discuss here the pathology of two PD-associated non-motor symptoms: olfactory dysfunction and depression. Olfactory dysfunction is one of the earliest non-motor symptoms in PD and predates the onset of motor symptoms. It is accompanied by early deposition of Lewy pathology and neurotransmitter alterations. Because of the correlation between olfactory dysfunction and an increased risk of progression to PD, olfactory testing can potentially be a specific diagnostic marker of PD in the prodromal stage. Depression is a prevalent PD-associated symptom and is often associated with reduced quality of life. Although the pathophysiology of depression in PD is unclear, studies suggest a causal relationship with abnormal neurotransmission and abnormal adult neurogenesis. Here, we summarize recent progress in the pathology of the non-motor symptoms of PD, aiming to provide better guidance for its effective management.
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Affiliation(s)
- Yeojin Bang
- College of Pharmacy and Institute of Pharmaceutical Sciences, CHA University, Pocheon, Gyeonggi-do, 11160, Republic of Korea
| | - Juhee Lim
- College of Pharmacy, Woosuk University, Wanju, Jeollabuk-do, 55338, Republic of Korea
| | - Hyun Jin Choi
- College of Pharmacy and Institute of Pharmaceutical Sciences, CHA University, Pocheon, Gyeonggi-do, 11160, Republic of Korea.
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Forest J, Chalençon L, Midroit M, Terrier C, Caillé I, Sacquet J, Benetollo C, Martin K, Richard M, Didier A, Mandairon N. Role of Adult-Born Versus Preexisting Neurons Born at P0 in Olfactory Perception in a Complex Olfactory Environment in Mice. Cereb Cortex 2021; 30:534-549. [PMID: 31216001 DOI: 10.1093/cercor/bhz105] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 03/26/2019] [Accepted: 04/21/2019] [Indexed: 12/11/2022] Open
Abstract
Olfactory perceptual learning is defined as an improvement in the discrimination of perceptually close odorants after passive exposure to these odorants. In mice, simple olfactory perceptual learning involving the discrimination of two odorants depends on an increased number of adult-born neurons in the olfactory bulb, which refines the bulbar output. However, the olfactory environment is complex, raising the question of the adjustment of the bulbar network to multiple discrimination challenges. Perceptual learning of 1 to 6 pairs of similar odorants led to discrimination of all learned odor pairs. Increasing complexity did not increase adult-born neuron survival but enhanced the number of adult-born neurons responding to learned odorants and their spine density. Moreover, only complex learning induced morphological changes in neurons of the granule cell layer born during the first day of life (P0). Selective optogenetic inactivation of either population confirmed functional involvement of adult-born neurons regardless of the enrichment complexity, while preexisting neurons were required for complex discrimination only.
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Affiliation(s)
- Jérémy Forest
- INSERM, U1028; CNRS, UMR5292; Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon, F-69000, France.,Claude Bernard University Lyon1 and University of Lyon, Lyon F-69000, France
| | - Laura Chalençon
- INSERM, U1028; CNRS, UMR5292; Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon, F-69000, France.,Claude Bernard University Lyon1 and University of Lyon, Lyon F-69000, France
| | - Maëllie Midroit
- INSERM, U1028; CNRS, UMR5292; Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon, F-69000, France.,Claude Bernard University Lyon1 and University of Lyon, Lyon F-69000, France
| | - Claire Terrier
- INSERM, U1028; CNRS, UMR5292; Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon, F-69000, France.,Claude Bernard University Lyon1 and University of Lyon, Lyon F-69000, France
| | - Isabelle Caillé
- Sorbonne Universités, Université Pierre et Marie Curie-Paris 06, Centre National de la Recherche Scientifique, UMR8246, INSERM U1130, Institut de Biologie Paris Seine, Neuroscience Paris Seine, and Sorbonne Paris Cité, Université Paris Diderot-Paris 7, Paris, France
| | - Joëlle Sacquet
- INSERM, U1028; CNRS, UMR5292; Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon, F-69000, France.,Claude Bernard University Lyon1 and University of Lyon, Lyon F-69000, France
| | - Claire Benetollo
- INSERM, U1028, CNRS, UMR5292, Lyon Neuroscience Research Center, Neurogenetic and Optogenetic Platform, University Lyon 1 and University of Lyon, Lyon F-69000, France
| | - Killian Martin
- INSERM, U1028; CNRS, UMR5292; Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon, F-69000, France.,Claude Bernard University Lyon1 and University of Lyon, Lyon F-69000, France
| | - Marion Richard
- INSERM, U1028; CNRS, UMR5292; Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon, F-69000, France.,Claude Bernard University Lyon1 and University of Lyon, Lyon F-69000, France
| | - Anne Didier
- INSERM, U1028; CNRS, UMR5292; Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon, F-69000, France.,Claude Bernard University Lyon1 and University of Lyon, Lyon F-69000, France
| | - Nathalie Mandairon
- INSERM, U1028; CNRS, UMR5292; Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon, F-69000, France.,Claude Bernard University Lyon1 and University of Lyon, Lyon F-69000, France
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11
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Suyama H, Egger V, Lukas M. Top-down acetylcholine signaling via olfactory bulb vasopressin cells contributes to social discrimination in rats. Commun Biol 2021; 4:603. [PMID: 34021245 PMCID: PMC8140101 DOI: 10.1038/s42003-021-02129-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 04/19/2021] [Indexed: 02/04/2023] Open
Abstract
Social discrimination in rats requires activation of the intrinsic bulbar vasopressin system, but it is unclear how this system comes into operation, as olfactory nerve stimulation primarily inhibits bulbar vasopressin cells (VPCs). Here we show that stimulation with a conspecific can activate bulbar VPCs, indicating that VPC activation depends on more than olfactory cues during social interaction. A series of in vitro electrophysiology, pharmacology and immunohistochemistry experiments implies that acetylcholine, probably originating from centrifugal projections, can enable olfactory nerve-evoked action potentials in VPCs. Finally, cholinergic activation of the vasopressin system contributes to vasopressin-dependent social discrimination, since recognition of a known rat was blocked by bulbar infusion of the muscarinic acetylcholine receptor antagonist atropine and rescued by additional bulbar application of vasopressin. Thus, our results implicate that top-down cholinergic modulation of bulbar VPC activity is involved in social discrimination in rats.
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Affiliation(s)
- Hajime Suyama
- Institute of Zoology, Neurophysiology, University of Regensburg, Regensburg, Germany
| | - Veronica Egger
- Institute of Zoology, Neurophysiology, University of Regensburg, Regensburg, Germany
| | - Michael Lukas
- Institute of Zoology, Neurophysiology, University of Regensburg, Regensburg, Germany.
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12
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Takahashi K, Tsuji M, Nakagawasai O, Katsuyama S, Miyagawa K, Kurokawa K, Mochida-Saito A, Iwasa M, Iwasa H, Takeda H, Tadano T. Activation of cholinergic system partially rescues olfactory dysfunction-induced learning and memory deficit in mice. Behav Brain Res 2021; 408:113283. [PMID: 33819530 DOI: 10.1016/j.bbr.2021.113283] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 03/18/2021] [Accepted: 03/30/2021] [Indexed: 02/07/2023]
Abstract
Deficits in olfaction are associated with neurodegenerative disorders such as Alzheimer's disease. A recent study reported that intranasal zinc sulfate (ZnSO4)-treated mice show olfaction and memory deficits. However, it remains unknown whether olfaction deficit-induced learning and memory impairment is associated with the cholinergic system in the brain. In this study, we evaluated olfactory function by the buried food find test, and learning and memory function by the Y-maze and passive avoidance tests in ZnSO4-treated mice. The expression of choline acetyltransferase (ChAT) protein in the olfactory bulb (OB), prefrontal cortex, hippocampus, and amygdala was assessed by western blotting. Moreover, we observed the effect of the acetylcholinesterase inhibitor physostigmine on ZnSO4-induced learning and memory deficits. We found that intranasal ZnSO4-treated mice exhibited olfactory dysfunction, while this change was recovered on day 14 after treatment. Both short-term and long-term learning and memory were impaired on days 4 and 7 after treatment with ZnSO4, whereas the former, but not the latter, was recovered on day 14 after treatment. A significant correlation was observed between olfactory function and short-term memory, but not long-term memory. Treatment with ZnSO4 decreased the ChAT level in the OB on day 4, and increased and decreased the ChAT levels in the OB and hippocampus on day 7, respectively. Physostigmine improved the ZnSO4-induced deficit in short-term, but not long-term, memory. Taken together, the present results suggest that short-term memory may be closely associated with olfactory function via the cholinergic system.
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Affiliation(s)
- Kohei Takahashi
- Department of Pharmacology, School of Pharmacy, International University of Health and Welfare, 2600-1 Kitakanemaru, Ohtawara, Tochigi 324-8501, Japan
| | - Minoru Tsuji
- Department of Pharmacology, School of Pharmacy, International University of Health and Welfare, 2600-1 Kitakanemaru, Ohtawara, Tochigi 324-8501, Japan.
| | - Osamu Nakagawasai
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai, Miyagi 981-8558, Japan
| | - Soh Katsuyama
- Division of Clinical Pharmacology and Pharmaceutics, Nihon Pharmaceutical University, 10281 Komuro, Kitaadachigun Inamachi, Saitama 362-0806, Japan
| | - Kazuya Miyagawa
- Department of Pharmacology, School of Pharmacy, International University of Health and Welfare, 2600-1 Kitakanemaru, Ohtawara, Tochigi 324-8501, Japan
| | - Kazuhiro Kurokawa
- Department of Pharmacology, School of Pharmacy, International University of Health and Welfare, 2600-1 Kitakanemaru, Ohtawara, Tochigi 324-8501, Japan
| | - Atsumi Mochida-Saito
- Department of Pharmacology, School of Pharmacy, International University of Health and Welfare, 2600-1 Kitakanemaru, Ohtawara, Tochigi 324-8501, Japan
| | - Masahiro Iwasa
- Nihon Berm Co., Ltd, 2-14-3 Nagatachou, Chiyoda-ku, Tokyo 100-0014, Japan
| | - Hiroyuki Iwasa
- Nihon Berm Co., Ltd, 2-14-3 Nagatachou, Chiyoda-ku, Tokyo 100-0014, Japan
| | - Hiroshi Takeda
- Department of Pharmacology, School of Pharmacy at Fukuoka, International University of Health and Welfare, 137-1 Enokizu, Okawa, Fukuoka 831-8501, Japan
| | - Takeshi Tadano
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai, Miyagi 981-8558, Japan; Complementary and Alternative Medicine Clinical Research and Development, Graduate School of Medicine Sciences, Kanazawa University, 13-1 Takaramachi, Kanazawa, Ishikawa 920-8640, Japan
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13
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Hanson E, Brandel-Ankrapp KL, Arenkiel BR. Dynamic Cholinergic Tone in the Basal Forebrain Reflects Reward-Seeking and Reinforcement During Olfactory Behavior. Front Cell Neurosci 2021; 15:635837. [PMID: 33603646 PMCID: PMC7884767 DOI: 10.3389/fncel.2021.635837] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 01/11/2021] [Indexed: 11/13/2022] Open
Abstract
Sensory perception underlies how we internalize and interact with the external world. In order to adapt to changing circumstances and interpret signals in a variety of contexts, sensation needs to be reliable, but perception of sensory input needs to be flexible. An important mediator of this flexibility is top-down regulation from the cholinergic basal forebrain. Basal forebrain projection neurons serve as pacemakers and gatekeepers for downstream neural networks, modulating circuit activity across diverse neuronal populations. This top-down control is necessary for sensory cue detection, learning, and memory, and is disproportionately disrupted in neurodegenerative diseases associated with cognitive decline. Intriguingly, cholinergic signaling acts locally within the basal forebrain to sculpt the activity of basal forebrain output neurons. To determine how local cholinergic signaling impacts basal forebrain output pathways that participate in top-down regulation, we sought to define the dynamics of cholinergic signaling within the basal forebrain during motivated behavior and learning. Toward this, we utilized fiber photometry and the genetically encoded acetylcholine indicator GAChR2.0 to define temporal patterns of cholinergic signaling in the basal forebrain during olfactory-guided, motivated behaviors and learning. We show that cholinergic signaling reliably increased during reward seeking behaviors, but was strongly suppressed by reward delivery in a go/no-go olfactory-cued discrimination task. The observed transient reduction in cholinergic tone was mirrored by a suppression in basal forebrain GABAergic neuronal activity. Together, these findings suggest that cholinergic tone in the basal forebrain changes rapidly to reflect reward-seeking behavior and positive reinforcement and may impact downstream circuitry that modulates olfaction.
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Affiliation(s)
- Elizabeth Hanson
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Katie L. Brandel-Ankrapp
- Postbaccalaureate Research Education Program, Baylor College of Medicine, Houston, TX, United States
| | - Benjamin R. Arenkiel
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
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14
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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: 31] [Impact Index Per Article: 7.8] [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.
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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.
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15
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Noradrenergic Activity in the Olfactory Bulb Is a Key Element for the Stability of Olfactory Memory. J Neurosci 2020; 40:9260-9271. [PMID: 33097638 DOI: 10.1523/jneurosci.1769-20.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 09/04/2020] [Accepted: 10/13/2020] [Indexed: 02/07/2023] Open
Abstract
Memory stability is essential for animal survival when environment and behavioral state change over short or long time spans. The stability of a memory can be expressed by its duration, its perseverance when conditions change as well as its specificity to the learned stimulus. Using optogenetic and pharmacological manipulations in male mice, we show that the presence of noradrenaline in the olfactory bulb during acquisition renders olfactory memories more stable. We show that while inhibition of noradrenaline transmission during an odor-reward acquisition has no acute effects, it alters perseverance, duration, and specificity of the memory. We use a computational approach to propose a proof of concept model showing that a single, simple network effect of noradrenaline on olfactory bulb dynamics can underlie these seemingly different behavioral effects. Our results show that acute changes in network dynamics can have long-term effects that extend beyond the network that was manipulated.SIGNIFICANCE STATEMENT Olfaction guides the behavior of animals. For successful survival, animals have to remember previously learned information and at the same time be able to acquire new memories. We show here that noradrenaline in the olfactory bulb, the first cortical relay of the olfactory information, is important for creating stable and specific olfactory memories. Memory stability, as expressed in perseverance, duration and specificity of the memory, is enhanced when noradrenergic inputs to the olfactory bulb are unaltered. We show that, computationally, our diverse behavioral results can be ascribed to noradrenaline-driven changes in neural dynamics. These results shed light on how very temporary changes in neuromodulation can have a variety of long-lasting effects on neural processing and behavior.
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16
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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: 2.0] [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.
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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
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17
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Böhm E, Brunert D, Rothermel M. Input dependent modulation of olfactory bulb activity by HDB GABAergic projections. Sci Rep 2020; 10:10696. [PMID: 32612119 PMCID: PMC7329849 DOI: 10.1038/s41598-020-67276-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 05/27/2020] [Indexed: 12/16/2022] Open
Abstract
Basal forebrain modulation of central circuits is associated with active sensation, attention, and learning. While cholinergic modulations have been studied extensively the effect of non-cholinergic basal forebrain subpopulations on sensory processing remains largely unclear. Here, we directly compare optogenetic manipulation effects of two major basal forebrain subpopulations on principal neuron activity in an early sensory processing area, i.e. mitral/tufted cells (MTCs) in the olfactory bulb. In contrast to cholinergic projections, which consistently increased MTC firing, activation of GABAergic fibers from basal forebrain to the olfactory bulb leads to differential modulation effects: while spontaneous MTC activity is mainly inhibited, odor-evoked firing is predominantly enhanced. Moreover, sniff-triggered averages revealed an enhancement of maximal sniff evoked firing amplitude and an inhibition of firing rates outside the maximal sniff phase. These findings demonstrate that GABAergic neuromodulation affects MTC firing in a bimodal, sensory-input dependent way, suggesting that GABAergic basal forebrain modulation could be an important factor in attention mediated filtering of sensory information to the brain.
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Affiliation(s)
- Erik Böhm
- Department of Chemosensation, AG Neuromodulation, Institute for Biology II, RWTH Aachen University, Aachen, 52074, Germany
| | - Daniela Brunert
- Department of Chemosensation, AG Neuromodulation, Institute for Biology II, RWTH Aachen University, Aachen, 52074, Germany
| | - Markus Rothermel
- Department of Chemosensation, AG Neuromodulation, Institute for Biology II, RWTH Aachen University, Aachen, 52074, Germany.
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18
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Imam N, Cleland TA. Rapid online learning and robust recall in a neuromorphic olfactory circuit. NAT MACH INTELL 2020; 2:181-191. [PMID: 38650843 PMCID: PMC11034913 DOI: 10.1038/s42256-020-0159-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Accepted: 02/07/2020] [Indexed: 01/02/2023]
Abstract
We present a neural algorithm for the rapid online learning and identification of odourant samples under noise, based on the architecture of the mammalian olfactory bulb and implemented on the Intel Loihi neuromorphic system. As with biological olfaction, the spike timing-based algorithm utilizes distributed, event-driven computations and rapid (one-shot) online learning. Spike timing-dependent plasticity rules operate iteratively over sequential gamma-frequency packets to construct odour representations from the activity of chemosensor arrays mounted in a wind tunnel. Learned odourants then are reliably identified despite strong destructive interference. Noise resistance is further enhanced by neuromodulation and contextual priming. Lifelong learning capabilities are enabled by adult neurogenesis. The algorithm is applicable to any signal identification problem in which high-dimensional signals are embedded in unknown backgrounds.
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Affiliation(s)
- Nabil Imam
- Neuromorphic Computing Laboratory, Intel Corporation, San Francisco, CA 94111, USA
| | - Thomas A. Cleland
- Computational Physiology Laboratory, Dept. Psychology, Cornell University, Ithaca, NY 14853, USA
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19
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Schilit Nitenson A, Manzano Nieves G, Poeta DL, Bahar R, Rachofsky C, Mandairon N, Bath KG. Acetylcholine Regulates Olfactory Perceptual Learning through Effects on Adult Neurogenesis. iScience 2019; 22:544-556. [PMID: 31855767 PMCID: PMC6926271 DOI: 10.1016/j.isci.2019.11.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 09/23/2019] [Accepted: 11/06/2019] [Indexed: 01/27/2023] Open
Abstract
Learning to perceptually discriminate between chemical signals in the environment (olfactory perceptual learning [OPL]) is critical for survival. Multiple mechanisms have been implicated in OPL, including modulation of neurogenesis and manipulation of cholinergic activity. However, whether these represent distinct processes regulating OPL or if cholinergic effects on OPL depend upon neurogenesis has remained an unresolved question. Using a combination of pharmacological and optogenetic approaches, cholinergic activity was shown to be both necessary and sufficient to drive OPL, and this process was dependent on the presence of newly born cells in the olfactory bulb (OB). This study is the first to directly demonstrate that cholinergic effects on OPL require adult OB neurogenesis. Acetylcholine modulates olfactory perceptual learning Cholinergic modulation alters olfactory bulb neurogenesis Cholinergic effects on olfactory perceptual learning require adult neurogenesis Cholinergic excitation does not alter the phenotype of newborn olfactory bulb cells
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Affiliation(s)
| | | | - Devon Lynn Poeta
- Department of Cognitive, Linguistic and Psychological Sciences, Brown University, 190 Thayer St., Box 1821, Providence, RI 02912, USA
| | - Ryan Bahar
- Department of Neuroscience, Brown University, Providence, RI 02912, USA
| | - Carolyn Rachofsky
- Department of Neuroscience, Brown University, Providence, RI 02912, USA
| | - Nathalie Mandairon
- INSERM, U1028, CNRS, UMR5292, Lyon Neuroscience Research Center, Lyon 69000, France
| | - Kevin G Bath
- Department of Cognitive, Linguistic and Psychological Sciences, Brown University, 190 Thayer St., Box 1821, Providence, RI 02912, USA.
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20
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Ross JM, Bendahmane M, Fletcher ML. Olfactory Bulb Muscarinic Acetylcholine Type 1 Receptors Are Required for Acquisition of Olfactory Fear Learning. Front Behav Neurosci 2019; 13:164. [PMID: 31379534 PMCID: PMC6659260 DOI: 10.3389/fnbeh.2019.00164] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 07/08/2019] [Indexed: 11/13/2022] Open
Abstract
The olfactory bulb (OB) receives significant cholinergic innervation and widely expresses cholinergic receptors. While acetylcholine (ACh) is essential for olfactory learning, the exact mechanisms by which ACh modulates olfactory learning and whether it is specifically required in the OB remains unknown. Using behavioral pharmacology and optogenetics, we investigated the role of OB ACh in a simple olfactory fear learning paradigm. We find that antagonizing muscarinic ACh receptors (mAChRs) in the OB during fear conditioning but not testing significantly reduces freezing to the conditioned odor, without altering olfactory abilities. Additionally, we demonstrate that m1 mAChRs, rather than m2, are required for acquisition of olfactory fear. Finally, using mice expressing channelrhodopsin in cholinergic neurons, we show that stimulating ACh release specifically in the OB during odor-shock pairing can strengthen olfactory fear learning. Together these results define a role for ACh in olfactory associative learning and OB glomerular plasticity.
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Affiliation(s)
- Jordan M. Ross
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center (UTHSC), Memphis, TN, United States
| | - Mounir Bendahmane
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, United States
| | - Max L. Fletcher
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center (UTHSC), Memphis, TN, United States
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21
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22
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Zhou FW, Puche AC, Shipley MT. Short-Term Plasticity at Olfactory Cortex to Granule Cell Synapses Requires Ca V2.1 Activation. Front Cell Neurosci 2018; 12:387. [PMID: 30416429 PMCID: PMC6212651 DOI: 10.3389/fncel.2018.00387] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 10/09/2018] [Indexed: 11/30/2022] Open
Abstract
Output projections of the olfactory bulb (OB) to the olfactory cortex (OCX) and reciprocal feedback projections from OCX provide rapid regulation of OB circuit dynamics and odor processing. Short-term synaptic plasticity (STP), a feature of many synaptic connections in the brain, can modulate the strength of feedback based on preceding network activity. We used light-gated cation channel channelrhodopsin-2 (ChR2) to investigate plasticity of excitatory synaptic currents (EPSCs) evoked at the OCX to granule cell (GC) synapse in the OB. Selective activation of OCX glutamatergic axons/terminals in OB generates strong, frequency-dependent STP in GCs. This plasticity was critically dependent on activation of CaV2.1 channels. As acetylcholine (ACh) modulates CaV2.1 channels in other brain regions and as cholinergic projections from the basal forebrain heavily target the GC layer (GCL) in OB, we investigated whether ACh modulates STP at the OCX→GC synapse. ACh decreases OCX→GC evoked EPSCs, it had no effect on STP. Thus, ACh impact on cortical feedback is independent of CaV2.1-mediated STP. Modulation of OCX feedback to the bulb by modulatory transmitters, such as ACh, or by frequency-dependent STP could regulate the precise balance of excitation and inhibition of GCs. As GCs are a major inhibitory source for OB output neurons, plasticity at the cortical feedback synapse can differentially impact OB output to higher-order networks in situations where ACh inputs are activated or by active sniff sampling of odors.
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Affiliation(s)
- Fu-Wen Zhou
- Department of Anatomy and Neurobiology, Program in Neurosciences, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Adam C Puche
- Department of Anatomy and Neurobiology, Program in Neurosciences, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Michael T Shipley
- Department of Anatomy and Neurobiology, Program in Neurosciences, University of Maryland School of Medicine, Baltimore, MD, United States
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23
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Spindle MS, Parsa PV, Bowles SG, D'Souza RD, Vijayaraghavan S. A dominant role for the beta 4 nicotinic receptor subunit in nicotinic modulation of glomerular microcircuits in the mouse olfactory bulb. J Neurophysiol 2018; 120:2036-2048. [PMID: 30089021 DOI: 10.1152/jn.00925.2017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Nicotinic acetylcholine receptors (nAChRs) regulate information transfer across the main olfactory bulb by instituting a high-pass intensity filter allowing for the filtering out of weak inputs. Excitation-driven inhibition of the glomerular microcircuit via GABA release from periglomerular cells appears to underlie this effect of nAChR activation. The multiplicity of nAChR subtypes and cellular locations raises questions about their respective roles in mediating their effects on the glomerular output. In this study, we address this issue by targeting heteromeric nAChRs using receptor knockouts (KOs) for the two dominant nAChR β-subunit genes known to be expressed in the central nervous system. KOs of the β2-nAChR subunit did not affect nAChR currents from mitral cells (MCs) but attenuated those from the external tufted (ET) cells. In slices from these animals, activation of nAChRs still effectively inhibited excitatory postsynaptic currents (EPSCs) and firing on MCs evoked by the olfactory nerve (ON) stimulation, thereby indicating that the filter mechanism was intact. On the other hand, recordings from β4-KOs showed that nAChR responses from MCs were abolished and those from ET cells were attenuated. Excitation-driven feedback was abolished as was the effect of nAChR activation on ON-evoked EPSCs. Experiments using calcium imaging showed that one possible consequence of the β2-subunit activation might be to alter the time course of calcium transients in juxtaglomerular neurons suggesting a role for these receptors in calcium signaling. Our results indicate that nAChRs containing the β4-subunit are critical in the filtering of odor inputs and play a determinant role in the cholinergic modulation of glomerular output. NEW & NOTEWORTHY In this study, using receptor gene knockouts we examine the relative contributions of heteromeric nAChR subtypes located on different cell types to this effect of receptor activation. Our results demonstrate that nAChRs containing the β4-subunit activate MCs resulting in feedback inhibition from glomerular interneurons. This period of inhibition results in the selective filtering of weak odor inputs providing one mechanism by which nAChRs can enhance discrimination between two closely related odors.
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Affiliation(s)
- Michael S Spindle
- Department of Physiology and Biophysics and the Neuroscience Program, University of Colorado, School of Medicine , Aurora, Colorado
| | - Pirooz V Parsa
- Department of Physiology and Biophysics and the Neuroscience Program, University of Colorado, School of Medicine , Aurora, Colorado
| | - Spencer G Bowles
- Department of Physiology and Biophysics and the Neuroscience Program, University of Colorado, School of Medicine , Aurora, Colorado
| | - Rinaldo D D'Souza
- Department of Physiology and Biophysics and the Neuroscience Program, University of Colorado, School of Medicine , Aurora, Colorado
| | - Sukumar Vijayaraghavan
- Department of Physiology and Biophysics and the Neuroscience Program, University of Colorado, School of Medicine , Aurora, Colorado
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24
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Osinski BL, Kim A, Xiao W, Mehta NM, Kay LM. Pharmacological manipulation of the olfactory bulb modulates beta oscillations: testing model predictions. J Neurophysiol 2018; 120:1090-1106. [PMID: 29847235 DOI: 10.1152/jn.00090.2018] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The mammalian olfactory bulb (OB) generates gamma (40-100 Hz) and beta (15-30 Hz) local field potential (LFP) oscillations. Gamma oscillations arise at the peak of inhalation supported by dendrodendritic interactions between glutamatergic mitral cells (MCs) and GABAergic granule cells (GCs). Beta oscillations are induced by odorants in learning or odor sensitization paradigms, but their mechanism and function are still poorly understood. When centrifugal OB inputs are blocked, beta oscillations disappear, but gamma oscillations persist. Centrifugal inputs target primarily GABAergic interneurons in the GC layer (GCL) and regulate GC excitability, suggesting a causal link between beta oscillations and GC excitability. Our previous modeling work predicted that convergence of excitatory/inhibitory inputs onto MCs and centrifugal inputs onto GCs increase GC excitability sufficiently to produce beta oscillations primarily through voltage dependent calcium channel-mediated GABA release, independently of NMDA channels. We test some of the predictions of this model by examining the influence of NMDA and muscarinic acetylcholine (ACh) receptors, which affect GC excitability in different ways, on beta oscillations. A few minutes after intrabulbar infusion, scopolamine (muscarinic antagonist) suppressed odor-evoked beta in response to a strong stimulus but increased beta power in response to a weak stimulus, as predicted by our model. Pyriform cortex (PC) beta power was unchanged. Oxotremorine (muscarinic agonist) suppressed all oscillations, likely from overinhibition. APV, an NMDA receptor antagonist, suppressed gamma oscillations selectively (in OB and PC), lending support to the model's prediction that beta oscillations can be supported independently of NMDA receptors. NEW & NOTEWORTHY Olfactory bulb local field potential beta oscillations appear to be gated by GABAergic granule cell excitability. Reducing excitability with scopolamine reduces beta induced by strong odors but increases beta induced by weak odors. Beta oscillations rely on the same synapse as gamma oscillations but, unlike gamma, can persist in the absence of NMDA receptor activation. Pyriform cortex beta oscillations maintain power when olfactory bulb beta power is low, and the system maintains beta band coherence.
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Affiliation(s)
- Bolesław L Osinski
- Graduate Program in Biophysical Sciences, The University of Chicago , Chicago, Illinois.,Institute for Mind and Biology, The University of Chicago , Chicago, Illinois
| | - Alex Kim
- The College, The University of Chicago , Chicago, Illinois
| | - Wenxi Xiao
- Masters Program in Computational Social Sciences, The University of Chicago , Chicago, Illinois
| | - Nisarg M Mehta
- Institute for Mind and Biology, The University of Chicago , Chicago, Illinois
| | - Leslie M Kay
- Institute for Mind and Biology, The University of Chicago , Chicago, Illinois.,Department of Psychology, The University of Chicago , Chicago, Illinois
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25
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Olfactory bulb acetylcholine release dishabituates odor responses and reinstates odor investigation. Nat Commun 2018; 9:1868. [PMID: 29760390 PMCID: PMC5951802 DOI: 10.1038/s41467-018-04371-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 04/25/2018] [Indexed: 11/08/2022] Open
Abstract
Habituation and dishabituation modulate the neural resources and behavioral significance allocated to incoming stimuli across the sensory systems. We characterize these processes in the mouse olfactory bulb (OB) and uncover a role for OB acetylcholine (ACh) in physiological and behavioral olfactory dishabituation. We use calcium imaging in both awake and anesthetized mice to determine the time course and magnitude of OB glomerular habituation during a prolonged odor presentation. In addition, we develop a novel behavioral investigation paradigm to determine how prolonged odor input affects odor salience. We find that manipulating OB ACh release during prolonged odor presentations using electrical or optogenetic stimulation rapidly modulates habituated glomerular odor responses and odor salience, causing mice to suddenly investigate a previously ignored odor. To demonstrate the ethological validity of this effect, we show that changing the visual context can lead to dishabituation of odor investigation behavior, which is blocked by cholinergic antagonists in the OB.
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26
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Tong MT, Kim TYP, Cleland TA. Kinase activity in the olfactory bulb is required for odor memory consolidation. ACTA ACUST UNITED AC 2018; 25:198-205. [PMID: 29661832 PMCID: PMC5903401 DOI: 10.1101/lm.046615.117] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 02/05/2018] [Indexed: 12/25/2022]
Abstract
Long-term fear memory formation in the hippocampus and neocortex depends upon brain-derived neurotrophic factor (BDNF) signaling after acquisition. Incremental, appetitive odor discrimination learning is thought to depend substantially on the differentiation of adult-born neurons within the olfactory bulb (OB)—a process that is closely associated with BDNF signaling. We sought to elucidate the role of neurotrophin signaling within the OB on odor memory consolidation. Male mice were trained on odor–reward associative discriminations after bilateral infusion of the kinase inhibitor K252a, or vehicle control, into the OB. K252a is a partially selective inhibitor of tyrosine kinase (Trk) receptors, including the TrkB receptor for BDNF, though it also inhibits other plasticity-related kinases such as PKC and CaMKII/IV. K252a infusion into the OB did not impair odor acquisition or short-term (2 h) memory for the learned discriminations, but significantly impaired long-term (48 h) odor memory (LTM). This LTM deficit also was associated with reduced selectivity for the conditioned odorant in a reward-seeking digging task. Infusions of K252a immediately prior to testing did not impair LTM recall. These results indicate that kinase activation in the OB is required for the consolidation of odor memory of incrementally acquired information.
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Affiliation(s)
- Michelle T Tong
- Department of Psychology, Cornell University, Ithaca, New York 14853, USA .,Department of Psychology, Earlham College, Richmond, Indiana 47374, USA
| | - Tae-Young P Kim
- Department of Psychology, Cornell University, Ithaca, New York 14853, USA
| | - Thomas A Cleland
- Department of Psychology, Cornell University, Ithaca, New York 14853, USA
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27
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Rountree-Harrison D, Burton TJ, Leamey CA, Sawatari A. Environmental Enrichment Expedites Acquisition and Improves Flexibility on a Temporal Sequencing Task in Mice. Front Behav Neurosci 2018; 12:51. [PMID: 29599712 PMCID: PMC5862792 DOI: 10.3389/fnbeh.2018.00051] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 02/28/2018] [Indexed: 01/09/2023] Open
Abstract
Environmental enrichment (EE) via increased opportunities for voluntary exercise, sensory stimulation and social interaction, can enhance the function of and behaviours regulated by cognitive circuits. Little is known, however, as to how this intervention affects performance on complex tasks that engage multiple, definable learning and memory systems. Accordingly, we utilised the Olfactory Temporal Order Discrimination (OTOD) task which requires animals to recall and report sequence information about a series of recently encountered olfactory stimuli. This approach allowed us to compare animals raised in either enriched or standard laboratory housing conditions on a number of measures, including the acquisition of a complex discrimination task, temporal sequence recall accuracy (i.e., the ability to accurately recall a sequences of events) and acuity (i.e., the ability to resolve past events that occurred in close temporal proximity), as well as cognitive flexibility tested in the style of a rule reversal and an Intra-Dimensional Shift (IDS). We found that enrichment accelerated the acquisition of the temporal order discrimination task, although neither accuracy nor acuity was affected at asymptotic performance levels. Further, while a subtle enhancement of overall performance was detected for both rule reversal and IDS versions of the task, accelerated performance recovery could only be attributed to the shift-like contingency change. These findings suggest that EE can affect specific elements of complex, multi-faceted cognitive processes.
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Affiliation(s)
- Darius Rountree-Harrison
- Discipline of Physiology, School of Medical Sciences and the Bosch Institute, University of Sydney, Sydney, NSW, Australia
| | - Thomas J Burton
- Discipline of Physiology, School of Medical Sciences and the Bosch Institute, University of Sydney, Sydney, NSW, Australia.,Animal Behavioural Facility, School of Medical Sciences and the Bosch Institute, University of Sydney, Sydney, NSW, Australia
| | - Catherine A Leamey
- Discipline of Physiology, School of Medical Sciences and the Bosch Institute, University of Sydney, Sydney, NSW, Australia
| | - Atomu Sawatari
- Discipline of Physiology, School of Medical Sciences and the Bosch Institute, University of Sydney, Sydney, NSW, Australia
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28
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Lizbinski KM, Dacks AM. Intrinsic and Extrinsic Neuromodulation of Olfactory Processing. Front Cell Neurosci 2018; 11:424. [PMID: 29375314 PMCID: PMC5767172 DOI: 10.3389/fncel.2017.00424] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 12/18/2017] [Indexed: 12/03/2022] Open
Abstract
Neuromodulation is a ubiquitous feature of neural systems, allowing flexible, context specific control over network dynamics. Neuromodulation was first described in invertebrate motor systems and early work established a basic dichotomy for neuromodulation as having either an intrinsic origin (i.e., neurons that participate in network coding) or an extrinsic origin (i.e., neurons from independent networks). In this conceptual dichotomy, intrinsic sources of neuromodulation provide a “memory” by adjusting network dynamics based upon previous and ongoing activation of the network itself, while extrinsic neuromodulators provide the context of ongoing activity of other neural networks. Although this dichotomy has been thoroughly considered in motor systems, it has received far less attention in sensory systems. In this review, we discuss intrinsic and extrinsic modulation in the context of olfactory processing in invertebrate and vertebrate model systems. We begin by discussing presynaptic modulation of olfactory sensory neurons by local interneurons (LNs) as a mechanism for gain control based on ongoing network activation. We then discuss the cell-class specific effects of serotonergic centrifugal neurons on olfactory processing. Finally, we briefly discuss the integration of intrinsic and extrinsic neuromodulation (metamodulation) as an effective mechanism for exerting global control over olfactory network dynamics. The heterogeneous nature of neuromodulation is a recurring theme throughout this review as the effects of both intrinsic and extrinsic modulation are generally non-uniform.
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Affiliation(s)
- Kristyn M Lizbinski
- Department of Biology, West Virginia University, Morgantown, WV, United States
| | - Andrew M Dacks
- Department of Biology, West Virginia University, Morgantown, WV, United States
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29
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Abstract
Generative models are computational models designed to generate appropriate values for all of their embedded variables, thereby simulating the response properties of a complex system based on the coordinated interactions of a multitude of physical mechanisms. In systems neuroscience, generative models are generally biophysically based compartmental models of neurons and networks that are explicitly multiscale, being constrained by experimental data at multiple levels of organization from cellular membrane properties to large-scale network dynamics. As such, they are able to explain the origins of emergent properties in complex systems, and serve as tests of sufficiency and as quantitative instantiations of working hypotheses that may be too complex to simply intuit. Moreover, when adequately constrained, generative biophysical models are able to predict novel experimental outcomes, and consequently are powerful tools for experimental design. We here outline a general strategy for the iterative design and implementation of generative, multiscale biophysical models of neural systems. We illustrate this process using our ongoing, iteratively developing model of the mammalian olfactory bulb. Because the olfactory bulb exhibits diverse and interesting properties at multiple scales of organization, it is an attractive system in which to illustrate the value of generative modeling across scales.
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Affiliation(s)
- Guoshi Li
- Department of Psychology, Cornell University, Ithaca, NY, USA
- Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA
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30
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Cholinergic neurotransmission and olfactory function in obstructive sleep apnea syndrome: a TMS study. Sleep Med 2017; 37:113-118. [PMID: 28899520 DOI: 10.1016/j.sleep.2017.06.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2017] [Revised: 06/11/2017] [Accepted: 06/15/2017] [Indexed: 11/19/2022]
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31
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Cortical afferent inhibition abnormalities reveal cholinergic dysfunction in Parkinson’s disease: a reappraisal. J Neural Transm (Vienna) 2017; 124:1417-1429. [DOI: 10.1007/s00702-017-1775-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 07/31/2017] [Indexed: 12/14/2022]
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32
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Heterogeneity of odorant identification impairment in patients with Alzheimer's Disease. Sci Rep 2017; 7:4798. [PMID: 28684764 PMCID: PMC5500500 DOI: 10.1038/s41598-017-05201-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 05/24/2017] [Indexed: 02/01/2023] Open
Abstract
Alzheimer’s disease (AD) patients exhibit olfactory dysfunction. However, the olfactory declineti precise nature is not fully understood. One hundred patients (60 AD, 28 amnestic mild cognitive impairment (aMCI), 12 Normal) were enrolled. All participants underwent olfactory function testing using an odour stick identification test for Japanese (OSIT-J). OSIT-J scores were significantly correlated with recall. We classified OSIT-J odorants into three groups: Category I, odorants that were difficult for normal aged subjects to identify; Category II, odorants that became harder to accurately identify with cognitive decline; and Category III, odorants that even AD patients could identify. We defined a “cognitive subset” consisting of six Category II OSIT-J odorants (perfume, rose, Japanese cypress, curry, India ink and gas leak odour). The ability to identify “cognitive subset” odours was significantly better indicator of cognitive status than the ability to identify “non-cognitive subset”, which consisted of the six remaining items. The ability to identify the gas leak odorant was decreased early in the aMCI stage, suggesting a need to reconsider the odours used to signal gas leaks. The “cognitive subset” would provide a more convenient and effective biomarker for diagnosing dementia in clinical settings.
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33
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Versace V, Langthaler PB, Sebastianelli L, Höller Y, Brigo F, Orioli A, Saltuari L, Nardone R. Impaired cholinergic transmission in patients with Parkinson's disease and olfactory dysfunction. J Neurol Sci 2017; 377:55-61. [PMID: 28477708 DOI: 10.1016/j.jns.2017.03.049] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 03/25/2017] [Accepted: 03/29/2017] [Indexed: 10/19/2022]
Abstract
Olfactory dysfunction represents a frequent and disturbing non-motor manifestation of Parkinson's disease (PD). The pathophysiology of olfactory dysfunction in PD is still poorly understood. Experimental evidence suggests that olfactory impairment could be related to central cholinergic dysfunction. Short latency afferent inhibition (SAI) technique gives the opportunity to test an inhibitory cholinergic circuit in the human cerebral motor cortex. The objective of the study was to assess the cholinergic function, as measured by SAI, in PD patients with different degrees of olfactory dysfunction. We applied SAI technique in 31 patients with PD. These patients also underwent Olfactory Event-Related Potentials (OERPs) studies to objectively evaluate the olfactory system and a battery of neuropsychological tests to assess the cognitive functions. Absent OERPs indicated a severe olfactory dysfunction in 13 subjects. The presence of OERPs with an alteration in latency and/or amplitude can be considered as a borderline condition of slight alteration of smell and was found in other 15 patients. Only 3 patients showed normal OERPs. SAI was significantly reduced in the PD patients with absent OERPs compared with those with present but abnormal OERPs. Neuropsychological examination showed a mild cognitive impairment in 12 out of 13 PD patients with severe olfactory dysfunction, and in 3 out of the 15 patients with borderline olfactory dysfunction. SAI abnormalities and presence of severe olfactory impairment strongly support the hypothesis of cholinergic dysfunction in some patients with PD, who will probably develop a dementia. Longitudinal studies are required to verify whether SAI abnormalities in PD patients with olfactory dysfunction can predict a future severe cognitive decline.
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Affiliation(s)
- Viviana Versace
- Department of Neurorehabilitation, Hospital of Vipiteno, Italy; Research Unit for Neurorehabilitation of South Tyrol, Italy
| | - Patrick B Langthaler
- Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria; Department of Mathematics, Paris Lodron University of Salzburg, Austria
| | - Luca Sebastianelli
- Department of Neurorehabilitation, Hospital of Vipiteno, Italy; Research Unit for Neurorehabilitation of South Tyrol, Italy
| | - Yvonne Höller
- Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria
| | - Francesco Brigo
- Department of Neurology, Franz Tappeiner Hospital, Merano, Italy; Department of Neurological and Movement Sciences, University of Verona, Italy
| | - Andrea Orioli
- Department of Neurology, Franz Tappeiner Hospital, Merano, Italy
| | - Leopold Saltuari
- Department of Neurology, Hochzirl Hospital, Zirl, Austria; Research Unit for Neurorehabilitation of South Tyrol, Italy
| | - Raffaele Nardone
- Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria; Department of Neurology, Franz Tappeiner Hospital, Merano, Italy.
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34
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Chan W, Singh S, Keshav T, Dewan R, Eberly C, Maurer R, Nunez-Parra A, Araneda RC. Mice Lacking M1 and M3 Muscarinic Acetylcholine Receptors Have Impaired Odor Discrimination and Learning. Front Synaptic Neurosci 2017; 9:4. [PMID: 28210219 PMCID: PMC5288360 DOI: 10.3389/fnsyn.2017.00004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 01/18/2017] [Indexed: 01/27/2023] Open
Abstract
The cholinergic system has extensive projections to the olfactory bulb (OB) where it produces a state-dependent regulation of sensory gating. Previous work has shown a prominent role of muscarinic acetylcholine (ACh) receptors (mAChRs) in regulating the excitability of OB neurons, in particular the M1 receptor. Here, we examined the contribution of M1 and M3 mAChR subtypes to olfactory processing using mice with a genetic deletion of these receptors, the M1−/− and the M1/M3−/− knockout (KO) mice. Genetic ablation of the M1 and M3 mAChRs resulted in a significant deficit in odor discrimination of closely related molecules, including stereoisomers. However, the discrimination of dissimilar molecules, social odors (e.g., urine) and novel object recognition was not affected. In addition the KO mice showed impaired learning in an associative odor-learning task, learning to discriminate odors at a slower rate, indicating that both short and long-term memory is disrupted by mAChR dysfunction. Interestingly, the KO mice exhibited decreased olfactory neurogenesis at younger ages, a deficit that was not maintained in older animals. In older animals, the olfactory deficit could be restored by increasing the number of new born neurons integrated into the OB after exposing them to an olfactory enriched environment, suggesting that muscarinic modulation and adult neurogenesis could be two different mechanism used by the olfactory system to improve olfactory processing.
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Affiliation(s)
- Wilson Chan
- Department of Biology, University of Maryland College Park, MD, USA
| | - Sanmeet Singh
- Department of Biology, University of Maryland College Park, MD, USA
| | - Taj Keshav
- Department of Biology, University of Maryland College Park, MD, USA
| | - Ramita Dewan
- Department of Biology, University of Maryland College Park, MD, USA
| | - Christian Eberly
- Department of Biology, University of Maryland College Park, MD, USA
| | - Robert Maurer
- Department of Biology, University of Maryland College Park, MD, USA
| | - Alexia Nunez-Parra
- Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile Santiago, Chile
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35
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de Almeida L, Idiart M, Dean O, Devore S, Smith DM, Linster C. Internal Cholinergic Regulation of Learning and Recall in a Model of Olfactory Processing. Front Cell Neurosci 2016; 10:256. [PMID: 27877112 PMCID: PMC5099168 DOI: 10.3389/fncel.2016.00256] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 10/18/2016] [Indexed: 12/02/2022] Open
Abstract
In the olfactory system, cholinergic modulation has been associated with contrast modulation and changes in receptive fields in the olfactory bulb, as well the learning of odor associations in olfactory cortex. Computational modeling and behavioral studies suggest that cholinergic modulation could improve sensory processing and learning while preventing pro-active interference when task demands are high. However, how sensory inputs and/or learning regulate incoming modulation has not yet been elucidated. We here use a computational model of the olfactory bulb, piriform cortex (PC) and horizontal limb of the diagonal band of Broca (HDB) to explore how olfactory learning could regulate cholinergic inputs to the system in a closed feedback loop. In our model, the novelty of an odor is reflected in firing rates and sparseness of cortical neurons in response to that odor and these firing rates can directly regulate learning in the system by modifying cholinergic inputs to the system. In the model, cholinergic neurons reduce their firing in response to familiar odors—reducing plasticity in the PC, but increase their firing in response to novel odor—increasing PC plasticity. Recordings from HDB neurons in awake behaving rats reflect predictions from the model by showing that a subset of neurons decrease their firing as an odor becomes familiar.
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Affiliation(s)
- Licurgo de Almeida
- Computational Physiology Lab, Department of Neurobiology and Behavior, Cornell University Ithaca, NY, USA
| | - Marco Idiart
- Physics Institute Federal University of Rio Grande do Sul (UFRGS) Porto Alegre, Brazil
| | - Owen Dean
- Computational Physiology Lab, Department of Neurobiology and Behavior, Cornell University Ithaca, NY, USA
| | - Sasha Devore
- Computational Physiology Lab, Department of Neurobiology and Behavior, Cornell University Ithaca, NY, USA
| | - David M Smith
- Department of Psychology, Cornell University Ithaca, NY, USA
| | - Christiane Linster
- Computational Physiology Lab, Department of Neurobiology and Behavior, Cornell University Ithaca, NY, USA
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36
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Carlson KS, Whitney MS, Gadziola MA, Deneris ES, Wesson DW. Preservation of Essential Odor-Guided Behaviors and Odor-Based Reversal Learning after Targeting Adult Brain Serotonin Synthesis. eNeuro 2016; 3:ENEURO.0257-16.2016. [PMID: 27896310 PMCID: PMC5112565 DOI: 10.1523/eneuro.0257-16.2016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2016] [Revised: 10/18/2016] [Accepted: 10/24/2016] [Indexed: 01/02/2023] Open
Abstract
The neurotransmitter serotonin (5-HT) is considered a powerful modulator of sensory system organization and function in a wide range of animals. The olfactory system is innervated by midbrain 5-HT neurons into both its primary and secondary odor-processing stages. Facilitated by this circuitry, 5-HT and its receptors modulate olfactory system function, including odor information input to the olfactory bulb. It is unknown, however, whether the olfactory system requires 5-HT for even its most basic behavioral functions. To address this question, we established a conditional genetic approach to specifically target adult brain tryptophan hydroxylase 2 (Tph2), encoding the rate-limiting enzyme in brain 5-HT synthesis, and nearly eliminate 5-HT from the mouse forebrain. Using this novel model, we investigated the behavior of 5-HT-depleted mice during performance in an olfactory go/no-go task. Surprisingly, the near elimination of 5-HT from the forebrain, including the olfactory bulbs, had no detectable effect on the ability of mice to perform the odor-based task. Tph2-targeted mice not only were able to learn the task, but also had levels of odor acuity similar to those of control mice when performing coarse odor discrimination. Both groups of mice spent similar amounts of time sampling odors during decision-making. Furthermore, odor reversal learning was identical between 5-HT-depleted and control mice. These results suggest that 5-HT neurotransmission is not necessary for the most essential aspects of olfaction, including odor learning, discrimination, and certain forms of cognitive flexibility.
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Affiliation(s)
| | | | - Marie A. Gadziola
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH, 44106
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37
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Hamamoto M, Kiyokage E, Sohn J, Hioki H, Harada T, Toida K. Structural basis for cholinergic regulation of neural circuits in the mouse olfactory bulb. J Comp Neurol 2016; 525:574-591. [PMID: 27491021 DOI: 10.1002/cne.24088] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 06/30/2016] [Accepted: 07/08/2016] [Indexed: 01/10/2023]
Abstract
Odor information is regulated by olfactory inputs, bulbar interneurons, and centrifugal inputs in the olfactory bulb (OB). Cholinergic neurons projecting from the nucleus of the horizontal limb of the diagonal band of Broca and the magnocellular preoptic nucleus are one of the primary centrifugal inputs to the OB. In this study, we focused on cholinergic regulation of the OB and analyzed neural morphology with a particular emphasis on the projection pathways of cholinergic neurons. Single-cell imaging of a specific neuron within dense fibers is critical to evaluate the structure and function of the neural circuits. We labeled cholinergic neurons by infection with virus vector and then reconstructed them three-dimensionally. We also examined the ultramicrostructure of synapses by electron microscopy tomography. To further clarify the function of cholinergic neurons, we performed confocal laser scanning microscopy to investigate whether other neurotransmitters are present within cholinergic axons in the OB. Our results showed the first visualization of complete cholinergic neurons, including axons projecting to the OB, and also revealed frequent axonal branching within the OB where it innervated multiple glomeruli in different areas. Furthermore, electron tomography demonstrated that cholinergic axons formed asymmetrical synapses with a morphological variety of thicknesses of the postsynaptic density. Although we have not yet detected the presence of other neurotransmitters, the range of synaptic morphology suggests multiple modes of transmission. The present study elucidates the ways that cholinergic neurons could contribute to the elaborate mechanisms involved in olfactory processing in the OB. J. Comp. Neurol. 525:574-591, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Masakazu Hamamoto
- Department of Anatomy, Kawasaki Medical School, Okayama, 701-0192, Japan.,Department of Otolaryngology, Kawasaki Medical School, Okayama, 701-0192, Japan
| | - Emi Kiyokage
- Department of Anatomy, Kawasaki Medical School, Okayama, 701-0192, Japan
| | - Jaerin Sohn
- Department of Morphological Brain Science, Graduate School of Medicine, Kyoto University, Kyoto, 606-8501, Japan.,Division of Cerebral Circuitry, National Institute for Physiological Sciences, Aichi, 444-8787, Japan
| | - Hiroyuki Hioki
- Department of Morphological Brain Science, Graduate School of Medicine, Kyoto University, Kyoto, 606-8501, Japan
| | - Tamotsu Harada
- Department of Otolaryngology, Kawasaki Medical School, Okayama, 701-0192, Japan
| | - Kazunori Toida
- Department of Anatomy, Kawasaki Medical School, Okayama, 701-0192, Japan.,Research Center for Ultra-High Voltage Electron Microscopy, Osaka University, Osaka, 567-0047, Japan
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38
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Neuromodulation of olfactory transformations. Curr Opin Neurobiol 2016; 40:170-177. [PMID: 27564660 DOI: 10.1016/j.conb.2016.07.006] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 07/12/2016] [Accepted: 07/13/2016] [Indexed: 12/26/2022]
Abstract
The olfactory bulb and piriform cortex are the best studied structures of the mammalian olfactory system and are heavily innervated by extrinsic neuromodulatory inputs. The state-dependent release of acetylcholine, norepinephrine, serotonin, and other neuromodulators into these olfactory structures alters a constellation of physiological parameters in neurons and synapses that together modify the computations performed on sensory signals. These modifications affect the specificity, detectability, discriminability, and other properties of odor representations and thereby govern perceptual performance. Whereas different neuromodulators have distinct cellular effects, and tend to be associated with nominally different functions, it also is clear that these purported functions overlap substantially, and that ad hoc hypotheses regarding the roles of particular neuromodulators may have reached the limits of their usefulness.
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39
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Fractal analysis reveals subclasses of neurons and suggests an explanation of their spontaneous activity. Neurosci Lett 2016; 626:54-8. [PMID: 27189719 DOI: 10.1016/j.neulet.2016.05.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Revised: 05/06/2016] [Accepted: 05/10/2016] [Indexed: 01/27/2023]
Abstract
The present work used fractal time series analysis (detrended fluctuation analysis; DFA) to examine the spontaneous activity of single neurons in an anesthetized animal model, specifically, the mitral cells in the rat main olfactory bulb. DFA bolstered previous research in suggesting two subclasses of mitral cells. Although there was no difference in the fractal scaling of the interspike interval series at the shorter timescales, there was a significant difference at longer timescales. Neurons in Group B exhibited fractal, power-law scaled interspike intervals, whereas neurons in Group A exhibited random variation. These results raise questions about the role of these different cells within the olfactory bulb and potential explanations of their dynamics. Specifically, self-organized criticality has been proposed as an explanation of fractal scaling in many natural systems, including neural systems. However, this theory is based on certain assumptions that do not clearly hold in the case of spontaneous neural activity, which likely reflects intrinsic cell dynamics rather than activity driven by external stimulation. Moreover, it is unclear how self-organized criticality might account for the random dynamics observed in Group A, and how these random dynamics might serve some functional role when embedded in the typical activity of the olfactory bulb. These theoretical considerations provide direction for additional experimental work.
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40
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Bendahmane M, Ogg MC, Ennis M, Fletcher ML. Increased olfactory bulb acetylcholine bi-directionally modulates glomerular odor sensitivity. Sci Rep 2016; 6:25808. [PMID: 27165547 PMCID: PMC4863144 DOI: 10.1038/srep25808] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 04/20/2016] [Indexed: 11/09/2022] Open
Abstract
The glomerular layer of the olfactory bulb (OB) receives heavy cholinergic input from the horizontal limb of the diagonal band of Broca (HDB) and expresses both muscarinic and nicotinic acetylcholine (ACh) receptors. However, the effects of ACh on OB glomerular odor responses remain unknown. Using calcium imaging in transgenic mice expressing the calcium indicator GCaMP2 in the mitral/tufted cells, we investigated the effect of ACh on the glomerular responses to increasing odor concentrations. Using HDB electrical stimulation and in vivo pharmacology, we find that increased OB ACh leads to dynamic, activity-dependent bi-directional modulation of glomerular odor response due to the combinatorial effects of both muscarinic and nicotinic activation. Using pharmacological manipulation to reveal the individual receptor type contributions, we find that m2 muscarinic receptor activation increases glomerular sensitivity to weak odor input whereas nicotinic receptor activation decreases sensitivity to strong input. Overall, we found that ACh in the OB increases glomerular sensitivity to odors and decreases activation thresholds. This effect, along with the decreased responses to strong odor input, reduces the response intensity range of individual glomeruli to increasing concentration making them more similar across the entire concentration range. As a result, odor representations are more similar as concentration increases.
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Affiliation(s)
- Mounir Bendahmane
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - M Cameron Ogg
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Matthew Ennis
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Max L Fletcher
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
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Bradley SP, Chapman PD, Lizbinski KM, Daly KC, Dacks AM. A Flight Sensory-Motor to Olfactory Processing Circuit in the Moth Manduca sexta. Front Neural Circuits 2016; 10:5. [PMID: 26909026 PMCID: PMC4754697 DOI: 10.3389/fncir.2016.00005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 01/25/2016] [Indexed: 12/02/2022] Open
Abstract
Neural circuits projecting information from motor to sensory pathways are common across sensory domains. These circuits typically modify sensory function as a result of motor pattern activation; this is particularly so in cases where the resultant behavior affects the sensory experience or its processing. However, such circuits have not been observed projecting to an olfactory pathway in any species despite well characterized active sampling behaviors that produce reafferent mechanical stimuli, such as sniffing in mammals and wing beating in the moth Manduca sexta. In this study we characterize a circuit that connects a flight sensory-motor center to an olfactory center in Manduca. This circuit consists of a single pair of histamine immunoreactive (HA-ir) neurons that project from the mesothoracic ganglion to innervate a subset of ventral antennal lobe (AL) glomeruli. Furthermore, within the AL we show that the M. sexta histamine B receptor (MsHisClB) is exclusively expressed by a subset of GABAergic and peptidergic LNs, which broadly project to all olfactory glomeruli. Finally, the HA-ir cell pair is present in fifth stage instar larvae; however, the absence of MsHisClB-ir in the larval antennal center indicates that the circuit is incomplete prior to metamorphosis and importantly prior to the expression of flight behavior. Although the functional consequences of this circuit remain unknown, these results provide the first detailed description of a circuit that interconnects an olfactory system with motor centers driving flight behaviors including odor-guided flight.
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Affiliation(s)
- Samual P Bradley
- Department of Biology, West Virginia University, Morgantown WV, USA
| | | | | | - Kevin C Daly
- Department of Biology, West Virginia University, Morgantown WV, USA
| | - Andrew M Dacks
- Department of Biology, West Virginia University, Morgantown WV, USA
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Devore S, Pender-Morris N, Dean O, Smith D, Linster C. Basal forebrain dynamics during nonassociative and associative olfactory learning. J Neurophysiol 2015; 115:423-33. [PMID: 26561601 DOI: 10.1152/jn.00572.2015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 11/10/2015] [Indexed: 12/28/2022] Open
Abstract
Cholinergic and GABAergic projections from the horizontal diagonal band (HDB) and medial preoptic area (MCPO) of the basal forebrain to the olfactory system are associated with odor discrimination and odor learning, as well as modulation of neural responses in olfactory structures. Whereas pharmacological and lesion studies give insights into the functional role of these modulatory inputs on a slow timescale, the response dynamics of neurons in the HDB/MCPO during olfactory behaviors have not been investigated. In this study we examined how these neurons respond during two olfactory behaviors: spontaneous investigation of odorants and odor-reward association learning. We observe rich heterogeneity in the response dynamics of individual HDB/MCPO neurons, with a substantial fraction of neurons exhibiting task-related modulation. HDB/MCPO neurons show both rapid and transient responses during bouts of odor investigation and slow, long-lasting modulation of overall response rate based on behavioral demands. Specifically, baseline rates were higher during the acquisition phase of an odor-reward association than during spontaneous investigation or the recall phase of an odor reward association. Our results suggest that modulatory projections from the HDB/MCPO are poised to influence olfactory processing on multiple timescales, from hundreds of milliseconds to minutes, and are therefore capable of rapidly setting olfactory network dynamics during odor processing and learning.
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Affiliation(s)
- Sasha Devore
- Department of Neurobiology and Behavior, Cornell University, Ithaca, New York; and
| | | | - Owen Dean
- Department of Neurobiology and Behavior, Cornell University, Ithaca, New York; and
| | - David Smith
- Department of Psychology, Cornell University, Ithaca, New York
| | - Christiane Linster
- Department of Neurobiology and Behavior, Cornell University, Ithaca, New York; and
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Kass MD, Guang SA, Moberly AH, McGann JP. Changes in Olfactory Sensory Neuron Physiology and Olfactory Perceptual Learning After Odorant Exposure in Adult Mice. Chem Senses 2015; 41:123-33. [PMID: 26514410 DOI: 10.1093/chemse/bjv065] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The adult olfactory system undergoes experience-dependent plasticity to adapt to the olfactory environment. This plasticity may be accompanied by perceptual changes, including improved olfactory discrimination. Here, we assessed experience-dependent changes in the perception of a homologous aldehyde pair by testing mice in a cross-habituation/dishabituation behavioral paradigm before and after a week-long ester-odorant exposure protocol. In a parallel experiment, we used optical neurophysiology to observe neurotransmitter release from olfactory sensory neuron (OSN) terminals in vivo, and thus compared primary sensory representations of the aldehydes before and after the week-long ester-odorant exposure in individual animals. Mice could not discriminate between the aldehydes during pre-exposure testing, but ester-exposed subjects spontaneously discriminated between the homologous pair after exposure, whereas home cage control mice cross-habituated. Ester exposure did not alter the spatial pattern, peak magnitude, or odorant-selectivity of aldehyde-evoked OSN input to olfactory bulb glomeruli, but did alter the temporal dynamics of that input to make the time course of OSN input more dissimilar between odorants. Together, these findings demonstrate that odor exposure can induce both physiological and perceptual changes in odor processing, and suggest that changes in the temporal patterns of OSN input to olfactory bulb glomeruli could induce differences in odor quality.
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Affiliation(s)
- Marley D Kass
- Behavioral & Systems Neuroscience Section, Department of Psychology, Rutgers University, 152 Frelinghuysen Road, Piscataway, NJ 08854, USA
| | - Stephanie A Guang
- Behavioral & Systems Neuroscience Section, Department of Psychology, Rutgers University, 152 Frelinghuysen Road, Piscataway, NJ 08854, USA
| | - Andrew H Moberly
- Behavioral & Systems Neuroscience Section, Department of Psychology, Rutgers University, 152 Frelinghuysen Road, Piscataway, NJ 08854, USA
| | - John P McGann
- Behavioral & Systems Neuroscience Section, Department of Psychology, Rutgers University, 152 Frelinghuysen Road, Piscataway, NJ 08854, USA
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Abstract
UNLABELLED Neuromodulation of olfactory circuits by acetylcholine (ACh) plays an important role in odor discrimination and learning. Early processing of chemosensory signals occurs in two functionally and anatomically distinct regions, the main and accessory olfactory bulbs (MOB and AOB), which receive extensive cholinergic input from the basal forebrain. Here, we explore the regulation of AOB and MOB circuits by ACh, and how cholinergic modulation influences olfactory-mediated behaviors in mice. Surprisingly, despite the presence of a conserved circuit, activation of muscarinic ACh receptors revealed marked differences in cholinergic modulation of output neurons: excitation in the AOB and inhibition in the MOB. Granule cells (GCs), the most abundant intrinsic neuron in the OB, also exhibited a complex muscarinic response. While GCs in the AOB were excited, MOB GCs exhibited a dual muscarinic action in the form of a hyperpolarization and an increase in excitability uncovered by cell depolarization. Furthermore, ACh influenced the input-output relationship of mitral cells in the AOB and MOB differently showing a net effect on gain in mitral cells of the MOB, but not in the AOB. Interestingly, despite the striking differences in neuromodulatory actions on output neurons, chemogenetic inhibition of cholinergic neurons produced similar perturbations in olfactory behaviors mediated by these two regions. Decreasing ACh in the OB disrupted the natural discrimination of molecularly related odors and the natural investigation of odors associated with social behaviors. Thus, the distinct neuromodulation by ACh in these circuits could underlie different solutions to the processing of general odors and semiochemicals, and the diverse olfactory behaviors they trigger. SIGNIFICANCE STATEMENT State-dependent cholinergic modulation of brain circuits is critical for several high-level cognitive functions, including attention and memory. Here, we provide new evidence that cholinergic modulation differentially regulates two parallel circuits that process chemosensory information, the accessory and main olfactory bulb (AOB and MOB, respectively). These circuits consist of remarkably similar synaptic arrangement and neuronal types, yet cholinergic regulation produced strikingly opposing effects in output and intrinsic neurons. Despite these differences, the chemogenetic reduction of cholinergic activity in freely behaving animals disrupted odor discrimination of simple odors, and the investigation of social odors associated with behaviors signaled by the Vomeronasal system.
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Leon-Sarmiento FE, Leon-Ariza JS, Prada DG, Leon-Ariza DS. Chemosensory disturbances-associated nanocholinergic dysfunction: The case of, not only, myasthenia gravis. J Neurol Sci 2015; 356:5-6. [PMID: 26139340 DOI: 10.1016/j.jns.2015.06.052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 06/24/2015] [Indexed: 11/27/2022]
Affiliation(s)
- Fidias E Leon-Sarmiento
- Smell & Taste Center, Department of Otorhinolaryngology, Perelman School of Medicine, Philadelphia, PA, USA.
| | - Juan S Leon-Ariza
- Mediciencias Research Group, Unicolciencias/Universidad Nacional, Bogota, Colombia; Visiting Scholar, Department of Radiology, Perelman School of Medicine, Philadelphia, PA, USA
| | - Diddier G Prada
- Department of Environmental Health, Harvard T. H. Chan School of Public Health, Boston, MA, USA
| | - Daniel S Leon-Ariza
- Mediciencias Research Group, Unicolciencias/Universidad Nacional, Bogota, Colombia; Faculty of Health Sciences, UDES, Bucaramanga, Colombia
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Li G, Linster C, Cleland TA. Functional differentiation of cholinergic and noradrenergic modulation in a biophysical model of olfactory bulb granule cells. J Neurophysiol 2015; 114:3177-200. [PMID: 26334007 DOI: 10.1152/jn.00324.2015] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 09/01/2015] [Indexed: 01/19/2023] Open
Abstract
Olfactory bulb granule cells are modulated by both acetylcholine (ACh) and norepinephrine (NE), but the effects of these neuromodulators have not been clearly distinguished. We used detailed biophysical simulations of granule cells, both alone and embedded in a microcircuit with mitral cells, to measure and distinguish the effects of ACh and NE on cellular and microcircuit function. Cholinergic and noradrenergic modulatory effects on granule cells were based on data obtained from slice experiments; specifically, ACh reduced the conductance densities of the potassium M current and the calcium-dependent potassium current, whereas NE nonmonotonically regulated the conductance density of an ohmic potassium current. We report that the effects of ACh and NE on granule cell physiology are distinct and functionally complementary to one another. ACh strongly regulates granule cell firing rates and afterpotentials, whereas NE bidirectionally regulates subthreshold membrane potentials. When combined, NE can regulate the ACh-induced expression of afterdepolarizing potentials and persistent firing. In a microcircuit simulation developed to investigate the effects of granule cell neuromodulation on mitral cell firing properties, ACh increased spike synchronization among mitral cells, whereas NE modulated the signal-to-noise ratio. Coapplication of ACh and NE both functionally improved the signal-to-noise ratio and enhanced spike synchronization among mitral cells. In summary, our computational results support distinct and complementary roles for ACh and NE in modulating olfactory bulb circuitry and suggest that NE may play a role in the regulation of cholinergic function.
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Affiliation(s)
- Guoshi Li
- Department of Psychology, Cornell University, Ithaca, New York;
| | - Christiane Linster
- Department of Neurobiology and Behavior, Cornell University, Ithaca, New York
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Zoli M, Pistillo F, Gotti C. Diversity of native nicotinic receptor subtypes in mammalian brain. Neuropharmacology 2015; 96:302-11. [DOI: 10.1016/j.neuropharm.2014.11.003] [Citation(s) in RCA: 167] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 10/11/2014] [Accepted: 11/08/2014] [Indexed: 01/01/2023]
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Abstract
Cholinergic [acetylcholine (ACh)] axons from the basal forebrain innervate olfactory bulb glomeruli, the initial site of synaptic integration in the olfactory system. Both nicotinic acetylcholine receptors (nAChRs) and muscarinic acetylcholine receptors (mAChRs) are expressed in glomeruli. The activation of nAChRs directly excites both mitral/tufted cells (MTCs) and external tufted cells (ETCs), the two major excitatory neurons that transmit glomerular output. The functional roles of mAChRs in glomerular circuits are unknown. We show that the restricted glomerular application of ACh causes rapid, brief nAChR-mediated excitation of both MTCs and ETCs in the mouse olfactory bulb. This excitation is followed by mAChR-mediated inhibition, which is blocked by GABAA receptor antagonists, indicating the engagement of periglomerular cells (PGCs) and/or short axon cells (SACs), the two major glomerular inhibitory neurons. Indeed, selective activation of glomerular mAChRs, with ionotropic GluRs and nAChRs blocked, increased IPSCs in MTCs and ETCs, indicating that mAChRs recruit glomerular inhibitory circuits. Selective activation of glomerular mAChRs in the presence of tetrodotoxin increased IPSCs in all glomerular neurons, indicating action potential-independent enhancement of GABA release from PGC and/or SAC dendrodendritic synapses. mAChR-mediated enhancement of GABA release also presynaptically suppressed the first synapse of the olfactory system via GABAB receptors on sensory terminals. Together, these results indicate that cholinergic modulation of glomerular circuits is biphasic, involving an initial excitation of MTC/ETCs mediated by nAChRs followed by inhibition mediated directly by mAChRs on PGCs/SACs. This may phasically enhance the sensitivity of glomerular outputs to odorants, an action that is consistent with recent in vivo findings.
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Hackett C, Choi C, O'Brien B, Shin P, Linster C. Odor Memory and Discrimination Covary as a Function of Delay between Encoding and Recall in Rats. Chem Senses 2015; 40:315-23. [PMID: 25899806 DOI: 10.1093/chemse/bjv013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Nonassociative odor learning paradigms are often used to assess memory, social recognition and neuromodulation of olfactory pathways. We here use a modified object recognition paradigm to investigate how an important task parameter, delay between encoding and recall trials, affects the properties of this memory. We show that both memory for a previously investigated odorant and discrimination of a novel odorant decay with delay time and that rats can remember an odorant for up to 45min after a single trial encoding event. The number of odorants that can be encoded, as well as the specificity of the encoded memory, decrease with increased delay and also depend on stimulus concentration. Memory for an odorant and discrimination of a novel odorant decay at approximately the same rate, whereas the specificity of the formed memory decays faster than the memory itself. These results have important implications for the interpretation of behavioral data obtained with this paradigm.
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Affiliation(s)
- Chelsea Hackett
- Computational Physiology Lab, Department of Neurobiology and Behavior, Cornell University, W249 Seeley G. Mudd Hall, Ithaca, NY 14853, USA
| | - Christina Choi
- Computational Physiology Lab, Department of Neurobiology and Behavior, Cornell University, W249 Seeley G. Mudd Hall, Ithaca, NY 14853, USA
| | - Brenna O'Brien
- Computational Physiology Lab, Department of Neurobiology and Behavior, Cornell University, W249 Seeley G. Mudd Hall, Ithaca, NY 14853, USA
| | - Philip Shin
- Computational Physiology Lab, Department of Neurobiology and Behavior, Cornell University, W249 Seeley G. Mudd Hall, Ithaca, NY 14853, USA
| | - Christiane Linster
- Computational Physiology Lab, Department of Neurobiology and Behavior, Cornell University, W249 Seeley G. Mudd Hall, Ithaca, NY 14853, USA
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50
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Zhang S, Xiao Q, Le W. Olfactory dysfunction and neurotransmitter disturbance in olfactory bulb of transgenic mice expressing human A53T mutant α-synuclein. PLoS One 2015; 10:e0119928. [PMID: 25799501 PMCID: PMC4370499 DOI: 10.1371/journal.pone.0119928] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 01/17/2015] [Indexed: 12/26/2022] Open
Abstract
Parkinson disease is a multi-system neurodegenerative disease characterized by both motor and non-motor symptoms. Hyposmia is one of the early non-motor symptoms occurring in more than 90% of Parkinson disease cases, which can precede motor symptoms even several years. Up to now, the relationship between hyposmia and Parkinson disease remains elusive. Lack of proper animal models of hyposmia restricts the investigation. In this study we assessed olfactory function in Prp-A53T-α-synuclein transgenic (αSynA53T) mice which had been reported to show age-dependent motor impairments and intracytoplasmic inclusions. We also examined cholinergic and dopaminergic systems in olfactory bulb of αSynA53T mice by immunofluorescent staining, enzyme linked immunosorbent assay and western blot. We found that compared to wild type littermates, αSynA53T mice at 6 months or older displayed a deficit of odor discrimination and odor detection. No significant changes were found in olfactory memory and odor habituation. Furthermore compared to wildtype littermates, in olfactory bulb of αSynA53T mice at 10 months old we detected a marked decrease of cholinergic neurons in mitral cell layer and a decrease of acetylcholinesterase activity, while dopaminergic neurons were found increased in glomerular layer, accompanied with an increase of tyrosine hydroxylase protein. Our studies indicate that αSynA53T mice have olfactory dysfunction before motor deficits occur, and the cholinergic and dopaminergic disturbance might be responsible for the Parkinson disease-related olfactory dysfunction.
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Affiliation(s)
- Sufang Zhang
- Institute of Neurology, RuiJin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qian Xiao
- Institute of Neurology, RuiJin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Weidong Le
- Institute of Neurology, RuiJin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- State Key Laboratory of Stem Cell Biology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences and Shanghai Jiao Tong University School of Medicine, Shanghai, China
- * E-mail:
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