1
|
Hu Y, Li H. Changes in Craniofacial Morphology Induced by Unilateral Nasal Obstruction in Mice of Different Ages. J Oral Rehabil 2024. [PMID: 39209766 DOI: 10.1111/joor.13849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 07/30/2024] [Accepted: 08/13/2024] [Indexed: 09/04/2024]
Abstract
BACKGROUND Nasal obstruction in humans leads to mouth breathing and subsequent hypoxia in the entire body. Furthermore, nasal obstruction in growing children affects craniofacial growth and development. OBJECTIVE To investigate the effects of unilateral nasal obstruction (UNO) on craniofacial growth in mice of different ages, particularly on the morphology of the nasomaxillary complex and mandible. METHODS Mice aged 3, 6 and 12 weeks were selected as representatives of juvenile, adolescent and adult stages, respectively. A total of 30 male C57BL/6J mice (10 mice each at the ages of 3, 6 and 12 weeks) were used in this study for a 3-week experiment. The mice in each age stage were randomly and evenly assigned to either the control group (C3+3, C6+3 and C12+3) or the experimental group (E3+3, E6+3 and E12+3). The UNO model in experimental group was constructed by plugging the mouse's left nostril, thereby disrupting its normal nasal breathing pattern and inducing hypoxia. The control group underwent the sham procedure. After 3 weeks, the length, width and height of the cranium, nasomaxillary complex and mandible of each group were measured on two-dimensional images constructed by micro-computed tomography. Furthermore, the impact of UNO on mouse growth was evaluated through the measurement of femoral length. RESULTS In juvenile mice, UNO inhibited the growth of cranial width, cranial height and mandibular length. In adolescent mice, UNO impeded the growth of the femoral length, cranial length, nasomaxillary length and mandibular length. In adult mice, no significant negative effects of UNO on craniofacial growth were found. CONCLUSION Referring to the experimental results, in addition to actively treating nasal obstruction in patients, it is important to monitor the growth of the mandible in juveniles, as well as the nasomaxillary and mandibular growth in adolescents during orthodontic clinical practice.
Collapse
Affiliation(s)
- Yun Hu
- Department of Orthodontics, Stomatological Hospital, School of Stomatology, Southern Medical University, Guangzhou, China
| | - Hegang Li
- Department of Orthodontics, Stomatological Hospital, School of Stomatology, Southern Medical University, Guangzhou, China
| |
Collapse
|
2
|
Kunkhyen T, Brechbill TR, Berg SPR, Pothuri P, Rangel AN, Gupta A, Cheetham CEJ. Cell type- and layer-specific plasticity of olfactory bulb interneurons following olfactory sensory neuron ablation. Sci Rep 2024; 14:17771. [PMID: 39090136 PMCID: PMC11294461 DOI: 10.1038/s41598-024-68649-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2024] [Accepted: 07/26/2024] [Indexed: 08/04/2024] Open
Abstract
Lifelong neurogenesis endows the mouse olfactory system with a capacity for regeneration that is unique in the mammalian nervous system. Throughout life, olfactory sensory neurons (OSNs) are generated from olfactory epithelium (OE) stem cells in the nose, while the subventricular zone generates neuroblasts that migrate to the olfactory bulb (OB) and differentiate into multiple populations of inhibitory interneurons. Methimazole (MMZ) selectively ablates OSNs, but OE neurogenesis enables OSN repopulation and gradual recovery of OSN input to the OB within 6 weeks. However, it is not known how OB interneurons are affected by this loss and subsequent regeneration of OSN input following MMZ treatment. We found that dopaminergic neuron density was significantly reduced 7-14 days post-MMZ but recovered substantially at 35 days. The density of parvalbumin-expressing interneurons was unaffected by MMZ; however, their soma size was significantly reduced at 7-14 days post-MMZ, recovering by 35 days. Surprisingly, we found a transient increase in the density of calretinin-expressing neurons in the glomerular and external plexiform layers, but not the granule cell layer, 7 days post-MMZ. This could not be accounted for by increased neurogenesis but may result from increased calretinin expression. Together, our data demonstrate cell type- and layer-specific changes in OB interneuron density and morphology after MMZ treatment, providing new insight into the range of plasticity mechanisms employed by OB circuits during loss and regeneration of sensory input.
Collapse
Affiliation(s)
- Tenzin Kunkhyen
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Taryn R Brechbill
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Sarah P R Berg
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Pranitha Pothuri
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Alexander N Rangel
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Ashna Gupta
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Claire E J Cheetham
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, 15213, USA.
| |
Collapse
|
3
|
Jiang X, Huang T, Chang F, Song Y, Wu D. Effects of Endoscopic Sinus Surgery on Olfactory Bulb Volume among Patients with Chronic Rhinosinusitis: A Systematic Review and Meta-Analysis. Am J Rhinol Allergy 2024; 38:251-257. [PMID: 38549395 DOI: 10.1177/19458924241241874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2024]
Abstract
BACKGROUND Endoscopic sinus surgery (ESS) could significantly improve olfactory function among patients with chronic rhinosinusitis (CRS). This study aimed to perform a meta-analysis to evaluate the effect of ESS on the olfactory bulb volume (OBV) among patients with CRS. METHODS A systemic search of PubMed, Medline, Embase, Web of Science, and other databases was conducted to identify studies assessing OBV changes in patients with CRS after ESS utilizing magnetic resonance imaging. RESULTS A total of four studies with 168 participants were included. Comparing the changes in OBV of patients with CRS before and after surgery within 3-6 months, the ESS significantly improved the overall OBV (P = 0.005, I2 = 66%), with the left OBV increased by 5.57mm3 (P = 0.84, I2 = 0%), and the right OBV increased by 8.63mm3 (P = 0.09, I2 = 53%). A difference in OBV persists between healthy controls and patients with CRS 3-6 months after ESS. The overall OBV of patients with CRS after ESS was significantly smaller than controls (mean difference = -3.84, P = 0.04), with a mean difference of 4.13mm3 on the left side (P = 0.72, I2 = 0%), and a mean difference of 3.22mm3 on the right side (P = 0.0001, I2 = 89%). CONCLUSIONS ESS significantly increases the OBV among patients with CRS.
Collapse
Affiliation(s)
- Xincen Jiang
- Department of Otolaryngology-Head and Neck Surgery, Peking University Third Hospital, Beijing, PR China
- Department of Medicine, Peking University, Beijing, China
| | - Tianhao Huang
- Department of Otolaryngology Head and Neck Surgery, The First Affiliated Hospital of Wenzhou Medical University, Zhejiang, People's Republic of China
| | - Feifan Chang
- Beijing Institute of Heart Lung and Blood Vessel Diseases, Beijing, China
| | - Yu Song
- Department of Otolaryngology-Head and Neck Surgery, Peking University Third Hospital, Beijing, PR China
| | - Dawei Wu
- Department of Otolaryngology-Head and Neck Surgery, Peking University Third Hospital, Beijing, PR China
| |
Collapse
|
4
|
Rufenacht KE, Asson AJ, Hossain K, Santoro SW. The influence of olfactory experience on the birthrates of olfactory sensory neurons with specific odorant receptor identities. Genesis 2024; 62:e23611. [PMID: 38888221 PMCID: PMC11189617 DOI: 10.1002/dvg.23611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Revised: 05/31/2024] [Accepted: 06/03/2024] [Indexed: 06/20/2024]
Abstract
Olfactory sensory neurons (OSNs) are one of a few neuron types that are generated continuously throughout life in mammals. The persistence of olfactory sensory neurogenesis beyond early development has long been thought to function simply to replace neurons that are lost or damaged through exposure to environmental insults. The possibility that olfactory sensory neurogenesis may also serve an adaptive function has received relatively little consideration, largely due to the assumption that the generation of new OSNs is stochastic with respect to OSN subtype, as defined by the single odorant receptor gene that each neural precursor stochastically chooses for expression out of hundreds of possibilities. Accordingly, the relative birthrates of different OSN subtypes are predicted to be constant and impervious to olfactory experience. This assumption has been called into question, however, by evidence that the birthrates of specific OSN subtypes can be selectively altered by manipulating olfactory experience through olfactory deprivation, enrichment, and conditioning paradigms. Moreover, studies of recovery of the OSN population following injury provide further evidence that olfactory sensory neurogenesis may not be strictly stochastic with respect to subtype. Here we review this evidence and consider mechanistic and functional implications of the prospect that specific olfactory experiences can regulate olfactory sensory neurogenesis rates in a subtype-selective manner.
Collapse
Affiliation(s)
- Karlin E Rufenacht
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Alexa J Asson
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Kawsar Hossain
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Stephen W Santoro
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado, USA
| |
Collapse
|
5
|
Ferreira A, Constantinescu VS, Malvaut S, Saghatelyan A, Hardy SV. Distinct forms of structural plasticity of adult-born interneuron spines in the mouse olfactory bulb induced by different odor learning paradigms. Commun Biol 2024; 7:420. [PMID: 38582915 PMCID: PMC10998910 DOI: 10.1038/s42003-024-06115-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 03/27/2024] [Indexed: 04/08/2024] Open
Abstract
The morpho-functional properties of neural networks constantly adapt in response to environmental stimuli. The olfactory bulb is particularly prone to constant reshaping of neural networks because of ongoing neurogenesis. It remains unclear whether the complexity of distinct odor-induced learning paradigms and sensory stimulation induces different forms of structural plasticity. In the present study, we automatically reconstructed spines in 3D from confocal images and performed unsupervised clustering based on morphometric features. We show that while sensory deprivation decreased the spine density of adult-born neurons without affecting the morphometric properties of these spines, simple and complex odor learning paradigms triggered distinct forms of structural plasticity. A simple odor learning task affected the morphometric properties of the spines, whereas a complex odor learning task induced changes in spine density. Our work reveals distinct forms of structural plasticity in the olfactory bulb tailored to the complexity of odor-learning paradigms and sensory inputs.
Collapse
Affiliation(s)
- Aymeric Ferreira
- CERVO Brain Research Center, Quebec City, QC, G1J 2G3, Canada
- Department of Biochemistry, Microbiology, and Bioinformatics, Université Laval, Quebec City, QC, G1V 0A6, Canada
| | - Vlad-Stefan Constantinescu
- CERVO Brain Research Center, Quebec City, QC, G1J 2G3, Canada
- Department of Psychiatry and Neuroscience, Université Laval, Quebec City, QC, G1V 0A6, Canada
| | - Sarah Malvaut
- CERVO Brain Research Center, Quebec City, QC, G1J 2G3, Canada
- Department of Psychiatry and Neuroscience, Université Laval, Quebec City, QC, G1V 0A6, Canada
| | - Armen Saghatelyan
- CERVO Brain Research Center, Quebec City, QC, G1J 2G3, Canada.
- Department of Psychiatry and Neuroscience, Université Laval, Quebec City, QC, G1V 0A6, Canada.
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, K1N 6N5, Canada.
| | - Simon V Hardy
- CERVO Brain Research Center, Quebec City, QC, G1J 2G3, Canada.
- Department of Biochemistry, Microbiology, and Bioinformatics, Université Laval, Quebec City, QC, G1V 0A6, Canada.
- Department of Computer Science and Software Engineering, Université Laval, Quebec City, QC, G1V 0A6, Canada.
| |
Collapse
|
6
|
Hossain K, Smith M, Santoro SW. A histological protocol for quantifying the birthrates of specific subtypes of olfactory sensory neurons in mice. STAR Protoc 2023; 4:102432. [PMID: 37436902 PMCID: PMC10511921 DOI: 10.1016/j.xpro.2023.102432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/16/2023] [Accepted: 06/12/2023] [Indexed: 07/14/2023] Open
Abstract
Mammals typically have hundreds of distinct olfactory sensory neuron subtypes, each defined by expression of a specific odorant receptor gene, which undergo neurogenesis throughout life at rates that can depend on olfactory experience. Here, we present a protocol to quantify the birthrates of specific neuron subtypes via the simultaneous detection of corresponding receptor mRNAs and 5-ethynyl-2'-deoxyuridine. For preparation prior to beginning the protocol, we detail procedures for generating odorant receptor-specific riboprobes and experimental mouse olfactory epithelial tissue sections. For complete details on the use and execution of this protocol, please refer to van der Linden et al. (2020).1.
Collapse
Affiliation(s)
- Kawsar Hossain
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Aurora, CO 80045, USA; Molecular and Cellular Life Sciences Program, University of Wyoming, Laramie, WY 82071, USA
| | - Madeline Smith
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Stephen W Santoro
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Aurora, CO 80045, USA.
| |
Collapse
|
7
|
Angelova A, Tiveron MC, Loizeau MD, Cremer H, Platel JC. Effects of sensory deprivation on glomerular interneurons in the mouse olfactory bulb: differences in mortality and phenotypic adjustment of dopaminergic neurons. Front Cell Neurosci 2023; 17:1170170. [PMID: 37377778 PMCID: PMC10291083 DOI: 10.3389/fncel.2023.1170170] [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: 02/20/2023] [Accepted: 05/26/2023] [Indexed: 06/29/2023] Open
Abstract
Neurogenesis persists in the mammalian subventricular zone after birth, producing various populations of olfactory bulb (OB) interneurons, including GABAergic and mixed dopaminergic/GABAergic (DA) neurons for the glomerular layer. While olfactory sensory activity is a major factor controlling the integration of new neurons, its impact on specific subtypes is not well understood. In this study we used genetic labeling of defined neuron subsets, in combination with reversible unilateral sensory deprivation and longitudinal in vivo imaging, to examine the behavior of postnatally born glomerular neurons. We find that a small fraction of GABAergic and of DA neurons die after 4 weeks of sensory deprivation while surviving DA-neurons exhibit a substantial decrease in tyrosine hydroxylase (TH) expression levels. Importantly, after reopening of the naris, cell death is arrested and TH levels go back to normal levels, indicating a specific adaptation to the level of sensory activity. We conclude that sensory deprivation induces adjustments in the population of glomerular neurons, involving both, cell death and adaptation of neurotransmitter use in specific neuron types. Our study highlights the dynamic nature of glomerular neurons in response to sensory deprivation and provide valuable insights into the plasticity and adaptability of the olfactory system.
Collapse
|
8
|
Murray HC, Saar G, Bai L, Bouraoud N, Dodd S, Highet B, Ryan B, Curtis MA, Koretsky A, Belluscio L. Progressive Spread of Beta-amyloid Pathology in an Olfactory-driven Amyloid Precursor Protein Mouse Model. Neuroscience 2023; 516:113-124. [PMID: 36716914 PMCID: PMC10065898 DOI: 10.1016/j.neuroscience.2023.01.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 12/04/2022] [Accepted: 01/13/2023] [Indexed: 01/29/2023]
Abstract
Years before Alzheimer's disease (AD) is diagnosed, patients experience an impaired sense of smell, and β-amyloid plaques accumulate within the olfactory mucosa and olfactory bulb (OB). The olfactory vector hypothesis proposes that external agents cause β-amyloid to aggregate and spread from the OB to connected downstream brain regions. To reproduce the slow accumulation of β-amyloid that occurs in human AD, we investigated the progressive accumulation of β-amyloid across the brain using a conditional mouse model that overexpresses a humanized mutant form of the amyloid precursor protein (hAPP) in olfactory sensory neurons. Using design-based stereology, we show the progressive accumulation of β-amyloid plaques within the OB and cortical olfactory regions with age. We also observe reduced OB volumes in these mice when hAPP expression begins prior-to but not post-weaning which we tracked using manganese-enhanced MRI. We therefore conclude that the reduced OB volume does not represent progressive degeneration but rather disrupted OB development. Overall, our data demonstrate that hAPP expression in the olfactory epithelium can lead to the accumulation and spread of β-amyloid through the olfactory system into the hippocampus, consistent with an olfactory system role in the early stages of β-amyloid-related AD progression.
Collapse
Affiliation(s)
- Helen C Murray
- Department of Anatomy and Medical Imaging and Centre for Brain Research, Faculty of Medical and Health Science, University of Auckland, Auckland 1023, New Zealand; Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Galit Saar
- Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Li Bai
- Circuits, Synapses and Molecular Signaling Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Nadia Bouraoud
- Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Stephen Dodd
- Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Blake Highet
- Department of Anatomy and Medical Imaging and Centre for Brain Research, Faculty of Medical and Health Science, University of Auckland, Auckland 1023, New Zealand.
| | - Brigid Ryan
- Department of Anatomy and Medical Imaging and Centre for Brain Research, Faculty of Medical and Health Science, University of Auckland, Auckland 1023, New Zealand.
| | - Maurice A Curtis
- Department of Anatomy and Medical Imaging and Centre for Brain Research, Faculty of Medical and Health Science, University of Auckland, Auckland 1023, New Zealand.
| | - Alan Koretsky
- Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.
| | | |
Collapse
|
9
|
Byrne DJ, Lipovsek M, Crespo A, Grubb MS. Brief sensory deprivation triggers plasticity of dopamine-synthesising enzyme expression in genetically labelled olfactory bulb dopaminergic neurons. Eur J Neurosci 2022; 56:3591-3612. [PMID: 35510299 PMCID: PMC9540594 DOI: 10.1111/ejn.15684] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 04/25/2022] [Indexed: 11/30/2022]
Abstract
In the glomerular layer of the olfactory bulb, local dopaminergic interneurons play a key role in regulating the flow of sensory information from nose to cortex. These dual dopamine- and GABA-releasing cells are capable of marked experience-dependent changes in the expression of neurotransmitter-synthesising enzymes, including tyrosine hydroxylase (TH). However, such plasticity has most commonly been studied in cell populations identified by their expression of the enzyme being studied and after long periods of sensory deprivation. Here, instead, we used brief 1- or 3-day manipulations of olfactory experience in juvenile mice, coupled with a conditional genetic approach that labelled neurons contingent upon their expression of the dopamine transporter (DAT-tdTomato). This enabled us to evaluate the potential for rapid changes in neurotransmitter-synthesising enzyme expression in an independently identified neuronal population. Our labelling strategy showed good specificity for olfactory bulb dopaminergic neurons, while revealing a minority sub-population of non-dopaminergic DAT-tdTomato cells that expressed the calcium-binding protein calretinin. Crucially, the proportions of these neuronal subtypes were not affected by brief alterations in sensory experience. Short-term olfactory manipulations also produced no significant changes in immunofluorescence or whole-bulb mRNA for the GABA-synthesising enzyme GAD67/Gad1. However, in bulbar DAT-tdTomato neurons, brief sensory deprivation was accompanied by a transient, small drop in immunofluorescence for the dopamine-synthesising enzyme dopa decarboxylase (DDC) and a sustained decrease for TH. Deprivation also produced a sustained decrease in whole-bulb Th mRNA. Careful characterisation of an independently identified, genetically labelled neuronal population therefore enabled us to uncover rapid experience-dependent changes in dopamine-synthesising enzyme expression.
Collapse
Affiliation(s)
- Darren J. Byrne
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience (IoPPN)King's College LondonLondonUK
| | - Marcela Lipovsek
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience (IoPPN)King's College LondonLondonUK
- Ear InstituteUniversity College LondonLondonUK
| | - Andres Crespo
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience (IoPPN)King's College LondonLondonUK
| | - Matthew S. Grubb
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience (IoPPN)King's College LondonLondonUK
| |
Collapse
|
10
|
Poessel M, Breuer N, Joshi A, Pampel A, Villringer A, Hummel T, Horstmann A. Reduced Olfactory Bulb Volume in Obesity and Its Relation to Metabolic Health Status. Front Hum Neurosci 2020; 14:586998. [PMID: 33328935 PMCID: PMC7729134 DOI: 10.3389/fnhum.2020.586998] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 11/03/2020] [Indexed: 12/12/2022] Open
Abstract
Smell perception plays an important role in eating behavior and might be involved in body weight gain. Since a body of literature implies that olfactory perception and function is hampered in obesity, we here investigate neuroanatomical correlates of this phenomenon. We assessed olfactory bulb (OB) volume with magnetic resonance imaging in 67 healthy participants with a body mass index (BMI) from 18.9 to 45.4 kg/m2 (mean = 28.58 ± 6.64). Moreover, we obtained psychophysiological data on olfactory ability (Sniffin' Sticks, Food associated odor test) and self-report measurements on eating behavior. Additionally, we collected parameters associated with metabolic health in obesity (waist-hip ratio, waist-height ratio, leptin levels, body fat percentage, fat mass index, insulin resistance) to investigate recently proposed mechanistic explanatory models of why olfaction may be altered in obesity. We showed that OB volume was significantly lower in participants with obesity when compared to those of normal weight. Moreover, we found weak to moderate negative correlations between OB volume and BMI and related measures of metabolic health, especially leptin, body fat percentage, waist-height ratio and insulin resistance. However, neither OB volume nor BMI were related to olfactory function in our young and healthy sample. Nevertheless, our results provide first indications that obesity is associated with brain anatomical changes in the OBs.
Collapse
Affiliation(s)
- Maria Poessel
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Integriertes Forschungs- und Behandlungszentrum (IFB) Adiposity Diseases, Leipzig University Medical Center, Leipzig, Germany
| | - Nora Breuer
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Integriertes Forschungs- und Behandlungszentrum (IFB) Adiposity Diseases, Leipzig University Medical Center, Leipzig, Germany
| | - Akshita Joshi
- Smell and Taste Clinic, Department of Otorhinolaryngology, University of Dresden Medical School, Dresden, Germany
| | - André Pampel
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Arno Villringer
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Day Clinic for Cognitive Neurology, University Hospital at the University of Leipzig, Leipzig, Germany
- Berlin School of Mind and Brain, Mind Brain Body Institute, Humboldt-Universität zu Berlin, Berlin, German
- Charité – Universitätsmedizin Berlin, Berlin, Germany
- International Max Planck Research School on the Life Course, Max Planck Institute for Human Development, Berlin, Germany
- International Max Planck Research School on the Neuroscience of Communication, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Thomas Hummel
- Smell and Taste Clinic, Department of Otorhinolaryngology, University of Dresden Medical School, Dresden, Germany
| | - Annette Horstmann
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Integriertes Forschungs- und Behandlungszentrum (IFB) Adiposity Diseases, Leipzig University Medical Center, Leipzig, Germany
- Department of Psychology and Logopedics, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Leipzig University Medical Center, Collaborative Research Council (CRC) 1052A5 ‘Obesity Mechanisms’, Leipzig, Germany
| |
Collapse
|
11
|
Nasal respiration is necessary for ketamine-dependent high frequency network oscillations and behavioral hyperactivity in rats. Sci Rep 2020; 10:18981. [PMID: 33149202 PMCID: PMC7642442 DOI: 10.1038/s41598-020-75641-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 10/05/2020] [Indexed: 12/12/2022] Open
Abstract
Changes in oscillatory activity are widely reported after subanesthetic ketamine, however their mechanisms of generation are unclear. Here, we tested the hypothesis that nasal respiration underlies the emergence of high-frequency oscillations (130–180 Hz, HFO) and behavioral activation after ketamine in freely moving rats. We found ketamine 20 mg/kg provoked “fast” theta sniffing in rodents which correlated with increased locomotor activity and HFO power in the OB. Bursts of ketamine-dependent HFO were coupled to “fast” theta frequency sniffing. Theta coupling of HFO bursts were also found in the prefrontal cortex and ventral striatum which, although of smaller amplitude, were coherent with OB activity. Haloperidol 1 mg/kg pretreatment prevented ketamine-dependent increases in fast sniffing and instead HFO coupling to slower basal respiration. Consistent with ketamine-dependent HFO being driven by nasal respiration, unilateral naris blockade led to an ipsilateral reduction in ketamine-dependent HFO power compared to the control side. Bilateral nares blockade reduced ketamine-induced hyperactivity and HFO power and frequency. These findings suggest that nasal airflow entrains ketamine-dependent HFO in diverse brain regions, and that the OB plays an important role in the broadcast of this rhythm.
Collapse
|
12
|
Fitzwater E, Coppola DM. Olfactory Deprivation and Enrichment: An Identity of Opposites? Chem Senses 2020; 46:5939855. [PMID: 33103187 DOI: 10.1093/chemse/bjaa071] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The effects of deprivation and enrichment on the electroolfactogram of mice were studied through the paradigms of unilateral naris occlusion and odor induction, respectively. Deprivation was shown to cause an increase in electroolfactogram amplitudes after 7 days. We also show that unilateral naris occlusion is not detrimental to the gross anatomical appearance or electroolfactogram of either the ipsilateral or contralateral olfactory epithelium even after year-long survival periods, consistent with our previous assumptions. Turning to induction, the increase in olfactory responses after a period of odor enrichment, could not be shown in CD-1 outbred mice for any odorant tried. However, consistent with classical studies, it was evident in C57BL/6J inbred mice, which are initially insensitive to isovaleric acid. As is the case for deprivation, enriching C57BL/6J mice with isovaleric acid causes an increase in their electroolfactogram response to this odorant over time. In several experiments on C57BL/6J mice, the odorant specificity, onset timing, recovery timing, and magnitude of the induction effect were studied. Considered together, the current findings and previous work from the laboratory support the counterintuitive conclusion that both compensatory plasticity in response to deprivation and induction in response to odor enrichment are caused by the same underlying homeostatic mechanism, the purpose of which is to preserve sensory information flow no matter the odorant milieu. This hypothesis, the detailed evidence supporting it, and speculations concerning human odor induction are discussed.
Collapse
Affiliation(s)
- Emily Fitzwater
- Department of Biology, Randolph-Macon College, Ashland, VA, USA
| | - David M Coppola
- Department of Biology, Randolph-Macon College, Ashland, VA, USA
| |
Collapse
|
13
|
Nartey MN, Peña-Castillo L, LeGrow M, Doré J, Bhattacharya S, Darby-King A, Carew SJ, Yuan Q, Harley CW, McLean JH. Learning-induced mRNA alterations in olfactory bulb mitral cells in neonatal rats. ACTA ACUST UNITED AC 2020; 27:209-221. [PMID: 32295841 PMCID: PMC7164515 DOI: 10.1101/lm.051177.119] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Accepted: 02/11/2020] [Indexed: 12/20/2022]
Abstract
In the olfactory bulb, a cAMP/PKA/CREB-dependent form of learning occurs in the first week of life that provides a unique mammalian model for defining the epigenetic role of this evolutionarily ancient plasticity cascade. Odor preference learning in the week-old rat pup is rapidly induced by a 10-min pairing of odor and stroking. Memory is demonstrable at 24 h, but not 48 h, posttraining. Using this paradigm, pups that showed peppermint preference 30 min posttraining were sacrificed 20 min later for laser microdissection of odor-encoding mitral cells. Controls were given odor only. Microarray analysis revealed that 13 nonprotein-coding mRNAs linked to mRNA translation and splicing and 11 protein-coding mRNAs linked to transcription differed with odor preference training. MicroRNA23b, a translation inhibitor of multiple plasticity-related mRNAs, was down-regulated. Protein-coding transcription was up-regulated for Sec23b, Clic2, Rpp14, Dcbld1, Magee2, Mstn, Fam229b, RGD1566265, and Mgst2. Gng12 and Srcg1 mRNAs were down-regulated. Increases in Sec23b, Clic2, and Dcbld1 proteins were confirmed in mitral cells in situ at the same time point following training. The protein-coding changes are consistent with extracellular matrix remodeling and ryanodine receptor involvement in odor preference learning. A role for CREB and AP1 as triggers of memory-related mRNA regulation is supported. The small number of gene changes identified in the mitral cell input/output link for 24 h memory will facilitate investigation of the nature, and reversibility, of changes supporting temporally restricted long-term memory.
Collapse
Affiliation(s)
- Michaelina N Nartey
- Divison of Biomedical Sciences, Memorial University of Newfoundland, St. John's, Newfoundland A1B3V6, Canada
| | - Lourdes Peña-Castillo
- Department of Computer Science, Memorial University of Newfoundland, St. John's, Newfoundland A1B3X5, Canada
| | - Megan LeGrow
- Divison of Biomedical Sciences, Memorial University of Newfoundland, St. John's, Newfoundland A1B3V6, Canada
| | - Jules Doré
- Divison of Biomedical Sciences, Memorial University of Newfoundland, St. John's, Newfoundland A1B3V6, Canada
| | - Sriya Bhattacharya
- Divison of Biomedical Sciences, Memorial University of Newfoundland, St. John's, Newfoundland A1B3V6, Canada
| | - Andrea Darby-King
- Divison of Biomedical Sciences, Memorial University of Newfoundland, St. John's, Newfoundland A1B3V6, Canada
| | - Samantha J Carew
- Divison of Biomedical Sciences, Memorial University of Newfoundland, St. John's, Newfoundland A1B3V6, Canada
| | - Qi Yuan
- Divison of Biomedical Sciences, Memorial University of Newfoundland, St. John's, Newfoundland A1B3V6, Canada
| | - Carolyn W Harley
- Department of Psychology, Memorial University of Newfoundland, St. John's, Newfoundland A1B3X9, Canada
| | - John H McLean
- Divison of Biomedical Sciences, Memorial University of Newfoundland, St. John's, Newfoundland A1B3V6, Canada
| |
Collapse
|
14
|
McDole B, Berger R, Guthrie K. Genetic Increases in Olfactory Bulb BDNF Do Not Enhance Survival of Adult-Born Granule Cells. Chem Senses 2020; 45:3-13. [PMID: 31562506 PMCID: PMC6923167 DOI: 10.1093/chemse/bjz058] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Adult-born neurons produced in the dentate gyrus subgranular zone (SGZ) develop as excitatory hippocampal granule cells (GCs), while those from the subventricular zone (SVZ) migrate to the olfactory bulb (OB), where most develop as GABAergic olfactory GCs. Both types of neurons express TrkB as they mature. Normally ~50% of new olfactory GCs survive, but survival declines if sensory drive is reduced. Increases in endogenous brain-derived neurotrophic factor (BDNF) in hippocampus, particularly with wheel running, enhance dentate GC survival. Whether survival of new olfactory GCs is impacted by augmenting BDNF in the OB, where they mature and integrate, is not known. Here, we determined if increasing OB BDNF expression enhances survival of new GCs, and if it counters their loss under conditions of reduced sensory activity. Neurogenesis was assessed under normal conditions, and following unilateral naris occlusion, in mice overexpressing BDNF in the granule cell layer (GCL). OB BDNF levels were significantly higher in transgenic mice compared to controls, and this was maintained following sensory deprivation. Bromodeoxyuridine (BrdU) cell birth dating showed that at 12-14 days post-BrdU, numbers of new GCs did not differ between genotypes, indicating normal recruitment to the OB. At later intervals, transgenic and control mice showed levels of GC loss in deprived and nondeprived animals that were indistinguishable, as was the incidence of apoptotic cells in the GCL. These results demonstrate that, in contrast to new dentate GCs, elevations in endogenous BDNF do not enhance survival of adult-born olfactory GCs.
Collapse
Affiliation(s)
- Brittnee McDole
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA
| | - Rachel Berger
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA
| | - Kathleen Guthrie
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA
| |
Collapse
|
15
|
Tepe B, Hill MC, Pekarek BT, Hunt PJ, Martin TJ, Martin JF, Arenkiel BR. Single-Cell RNA-Seq of Mouse Olfactory Bulb Reveals Cellular Heterogeneity and Activity-Dependent Molecular Census of Adult-Born Neurons. Cell Rep 2019; 25:2689-2703.e3. [PMID: 30517858 PMCID: PMC6342206 DOI: 10.1016/j.celrep.2018.11.034] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 09/18/2018] [Accepted: 11/07/2018] [Indexed: 12/19/2022] Open
Abstract
Cellular heterogeneity within the mammalian brain poses a challenge
toward understanding its complex functions. Within the olfactory bulb, odor
information is processed by subtypes of inhibitory interneurons whose
heterogeneity and functionality are influenced by ongoing adult neurogenesis. To
investigate this cellular heterogeneity and better understand adult-born neuron
development, we utilized single-cell RNA sequencing and computational modeling
to reveal diverse and transcriptionally distinct neuronal and nonneuronal cell
types. We also analyzed molecular changes during adult-born interneuron
maturation and uncovered developmental programs within their gene expression
profiles. Finally, we identified that distinct neuronal subtypes are
differentially affected by sensory experience. Together, these data provide a
transcriptome-based foundation for investigating subtype-specific neuronal
function in the olfactory bulb (OB), charting the molecular profiles that arise
during the maturation and integration of adult-born neurons and how they
dynamically change in an activity-dependent manner. Using single-cell sequencing, Tepe et al. describe cellular heterogeneity
in the mouse olfactory bulb, uncover markers for each cell type, and reveal
differentially regulated genes in adult-born neurons. These findings provide a
framework for studying cell-type-specific functions and circuit integration in
the mammalian brain.
Collapse
Affiliation(s)
- Burak Tepe
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Matthew C Hill
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Brandon T Pekarek
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Patrick J Hunt
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Medical Scientist Training Program, Baylor College of Medicine, Houston, TX 77030, USA
| | - Thomas J Martin
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - James F Martin
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA; The Texas Heart Institute, 6770 Bertner Avenue, Houston, TX 77030, USA; Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Benjamin R Arenkiel
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA; McNair Medical Institute, Baylor College of Medicine, Houston, TX 77030, USA.
| |
Collapse
|
16
|
Platel JC, Angelova A, Bugeon S, Wallace J, Ganay T, Chudotvorova I, Deloulme JC, Béclin C, Tiveron MC, Coré N, Murthy VN, Cremer H. Neuronal integration in the adult mouse olfactory bulb is a non-selective addition process. eLife 2019; 8:44830. [PMID: 31294694 PMCID: PMC6634973 DOI: 10.7554/elife.44830] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 07/07/2019] [Indexed: 12/25/2022] Open
Abstract
Adult neurogenesis in the olfactory bulb (OB) is considered as a competition in which neurons scramble during a critical selection period for integration and survival. Moreover, newborn neurons are thought to replace pre-existing ones that die. Despite indirect evidence supporting this model, systematic in vivo observations are still scarce. We used two-photon in vivo imaging to study neuronal integration and survival. We show that loss of new neurons in the OB after arrival at terminal positions occurs only at low levels. Moreover, long-term observations showed that no substantial cell death occurred at later stages. Neuronal death was induced by standard doses of thymidine analogs, but disappeared when low doses were used. Finally, we demonstrate that the OB grows throughout life. This shows that neuronal selection during OB-neurogenesis does not occur after neurons reached stable positions. Moreover, this suggests that OB neurogenesis does not represent neuronal turnover but lifelong neuronal addition.
Collapse
Affiliation(s)
| | | | - Stephane Bugeon
- Aix-Marseille University, CNRS, IBDM, UMR 7288, Marseille, France
| | - Jenelle Wallace
- Department of Molecular & Cellular Biology, Harvard University, Cambridge, United States
| | - Thibault Ganay
- Aix-Marseille University, CNRS, IBDM, UMR 7288, Marseille, France
| | | | | | | | | | - Nathalie Coré
- Aix-Marseille University, CNRS, IBDM, UMR 7288, Marseille, France
| | - Venkatesh N Murthy
- Department of Molecular & Cellular Biology, Harvard University, Cambridge, United States
| | - Harold Cremer
- Aix-Marseille University, CNRS, IBDM, UMR 7288, Marseille, France
| |
Collapse
|
17
|
Strauch C, Manahan-Vaughan D. In the Piriform Cortex, the Primary Impetus for Information Encoding through Synaptic Plasticity Is Provided by Descending Rather than Ascending Olfactory Inputs. Cereb Cortex 2019; 28:764-776. [PMID: 29186359 DOI: 10.1093/cercor/bhx315] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Indexed: 12/27/2022] Open
Abstract
Information encoding by means of persistent changes in synaptic strength supports long-term information storage and memory in structures such as the hippocampus. In the piriform cortex (PC), that engages in the processing of associative memory, only short-term synaptic plasticity has been described to date, both in vitro and in anesthetized rodents in vivo. Whether the PC maintains changes in synaptic strength for longer periods of time is unknown: Such a property would indicate that it can serve as a repository for long-term memories. Here, we report that in freely behaving animals, frequency-dependent synaptic plasticity does not occur in the anterior PC (aPC) following patterned stimulation of the olfactory bulb (OB). Naris closure changed action potential properties of aPC neurons and enabled expression of long-term potentiation (LTP) by OB stimulation, indicating that an intrinsic ability to express synaptic plasticity is present. Odor discrimination and categorization in the aPC is supported by descending inputs from the orbitofrontal cortex (OFC). Here, OFC stimulation resulted in LTP (>4 h), suggesting that this structure plays an important role in promoting information encoding through synaptic plasticity in the aPC. These persistent changes in synaptic strength are likely to comprise a means through which long-term memories are encoded and/or retained in the PC.
Collapse
Affiliation(s)
- Christina Strauch
- Department of Neurophysiology, Medical Faculty.,International Graduate School for Neuroscience, Ruhr University Bochum, Universitaetsstr. 150, 44780 Bochum, Germany
| | - Denise Manahan-Vaughan
- Department of Neurophysiology, Medical Faculty.,International Graduate School for Neuroscience, Ruhr University Bochum, Universitaetsstr. 150, 44780 Bochum, Germany
| |
Collapse
|
18
|
Angelova A, Platel JC, Béclin C, Cremer H, Coré N. Characterization of perinatally born glutamatergic neurons of the mouse olfactory bulb based on NeuroD6 expression reveals their resistance to sensory deprivation. J Comp Neurol 2019; 527:1245-1260. [PMID: 30592042 DOI: 10.1002/cne.24621] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 12/21/2018] [Accepted: 12/21/2018] [Indexed: 11/10/2022]
Abstract
During postnatal olfactory bulb (OB) neurogenesis, predetermined stem cells residing in the ventricular-subventricular zone continuously generate progenitors that migrate in the rostral migratory stream and integrate into the OB. Although the vast majority of these postnatally generated interneurons are inhibitory, a sub-fraction represents glutamatergic neurons that integrate into the superficial glomerular layer. In the present work, we demonstrate that the bHLH transcription factor NeuroD6 is specifically and transitorily expressed in the dorsal neurogenic lineage that generates glutamatergic juxtaglomerular cells (JGCs) for the OB. Using lineage tracing combined with whole brain clearing, we provide new insight into timing of generation, morphology, and connectivity of glutamatergic JGCs. Specifically, we show that all glutamatergic JGCs send complex axons with varying projection patterns into different layers of the OB. Moreover, we find that, contrary to GABAergic OB interneurons, glutamatergic JGCs survive under sensory deprivation, indicating that inhibitory and excitatory populations are differentially susceptible to environmental stimulation.
Collapse
Affiliation(s)
- Alexandra Angelova
- Aix Marseille Univ, CNRS UMR 7288, Developmental Biology Institute of Marseille (IBDM), Parc scientifique de Luminy, Marseille, France
| | - Jean-Claude Platel
- Aix Marseille Univ, CNRS UMR 7288, Developmental Biology Institute of Marseille (IBDM), Parc scientifique de Luminy, Marseille, France
| | - Christophe Béclin
- Aix Marseille Univ, CNRS UMR 7288, Developmental Biology Institute of Marseille (IBDM), Parc scientifique de Luminy, Marseille, France
| | - Harold Cremer
- Aix Marseille Univ, CNRS UMR 7288, Developmental Biology Institute of Marseille (IBDM), Parc scientifique de Luminy, Marseille, France
| | - Nathalie Coré
- Aix Marseille Univ, CNRS UMR 7288, Developmental Biology Institute of Marseille (IBDM), Parc scientifique de Luminy, Marseille, France
| |
Collapse
|
19
|
Pellegrino R, Han P, Reither N, Hummel T. Effectiveness of olfactory training on different severities of posttraumatic loss of smell. Laryngoscope 2019; 129:1737-1743. [DOI: 10.1002/lary.27832] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 12/18/2018] [Accepted: 01/07/2019] [Indexed: 11/09/2022]
Affiliation(s)
- Robert Pellegrino
- Smell and Taste Clinic, Department of Otorhinolaryngology; Dresden University of Technology; Dresden Germany
- Department of Food Science; Institute of Agriculture, University of Tennessee; Knoxville Tennessee U.S.A
| | - Pengfei Han
- Smell and Taste Clinic, Department of Otorhinolaryngology; Dresden University of Technology; Dresden Germany
| | - Nicole Reither
- Smell and Taste Clinic, Department of Otorhinolaryngology; Dresden University of Technology; Dresden Germany
| | - Thomas Hummel
- Smell and Taste Clinic, Department of Otorhinolaryngology; Dresden University of Technology; Dresden Germany
| |
Collapse
|
20
|
Tseng CS, Chou SJ, Huang YS. CPEB4-Dependent Neonate-Born Granule Cells Are Required for Olfactory Discrimination. Front Behav Neurosci 2019; 13:5. [PMID: 30728769 PMCID: PMC6351472 DOI: 10.3389/fnbeh.2019.00005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 01/08/2019] [Indexed: 11/23/2022] Open
Abstract
The rodent olfactory bulb (OB) contains two distinct populations of postnatally born interneurons, mainly granule cells (GCs), to support local circuits throughout life. During the early postnatal period (i.e., 2 weeks after birth), GCs are mostly produced locally from progenitor cells in the OB with a proportion of them deriving from proliferating cells in the rostral migratory stream (RMS). Afterward, the replenishment of GCs involves differentiated neuroblasts from the subventricular zone (SVZ) in a process known as adult neurogenesis. Although numerous studies have addressed the role of SVZ-born GCs in olfactory behaviors, the function of GCs produced early postnatally in the OB remains elusive. Our previous study demonstrated that the translational regulator, cytoplasmic polyadenylation element-binding protein 4 (CPEB4), is a survival factor exclusively for neonate-born but not SVZ/adult-derived GCs, so CPEB4-knockout (KO) mice provide unique leverage to study early postnatal-born GC-regulated olfactory functions. CPEB4-KO mice with hypoplastic OBs showed normal olfactory sensitivity and short-term memory, but impaired ability to spontaneously discriminate two odors. Such olfactory dysfunction was recapitulated in specific ablation of Cpeb4 gene in inhibitory interneurons but not in excitatory projection neurons or SVZ-derived interneurons. The continuous supply of GCs from adult neurogenesis eventually restored the OB size but not the discrimination function in 6-month-old KO mice. Hence, in the early postnatal OB, whose function cannot be replaced by adult-born GCs, construct critical circuits for odor discrimination.
Collapse
Affiliation(s)
- Ching-San Tseng
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Shen-Ju Chou
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Yi-Shuian Huang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| |
Collapse
|
21
|
Negoias S, Pietsch K, Hummel T. Changes in olfactory bulb volume following lateralized olfactory training. Brain Imaging Behav 2018; 11:998-1005. [PMID: 27448159 DOI: 10.1007/s11682-016-9567-9] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Repeated exposure to odors modifies olfactory function. Consequently, "olfactory training" plays a significant role in hyposmia treatment. In addition, numerous studies show that the olfactory bulb (OB) volume changes in disorders associated with olfactory dysfunction. Aim of this study was to investigate whether and how olfactory bulb volume changes in relation to lateralized olfactory training in healthy people. Over a period of 4 months, 97 healthy participants (63 females and 34 males, mean age: 23.74 ± 4.16 years, age range: 19-43 years) performed olfactory training by exposing the same nostril twice a day to 4 odors (lemon, rose, eucalyptus and cloves) while closing the other nostril. Before and after olfactory training, magnetic resonance imaging (MRI) scans were performed to measure OB volume. Furthermore, participants underwent lateralized odor threshold and odor identification testing using the "Sniffin' Sticks" test battery.OB volume increased significantly after olfactory training (11.3 % and 13.1 % respectively) for both trained and untrained nostril. No significant effects of sex, duration and frequency of training or age of the subjects were seen. Interestingly, PEA odor thresholds worsened after training, while olfactory identification remained unchanged.These data show for the first time in humans that olfactory training may involve top-down process, which ultimately lead to a bilateral increase in olfactory bulb volume.
Collapse
Affiliation(s)
- S Negoias
- Smell & Taste Clinic, Department of Otorhinolaryngology, Head and Neck Surgery, Technical University Dresden, Fetscherstr. 74, 01307, Dresden, Germany. .,Department of Otorhinolaryngology, Head and Neck Surgery, Inselspital, Bern University Hospital, University of Bern, Freiburgstrasse, 3010, Bern, Switzerland.
| | - K Pietsch
- Smell & Taste Clinic, Department of Otorhinolaryngology, Head and Neck Surgery, Technical University Dresden, Fetscherstr. 74, 01307, Dresden, Germany
| | - T Hummel
- Smell & Taste Clinic, Department of Otorhinolaryngology, Head and Neck Surgery, Technical University Dresden, Fetscherstr. 74, 01307, Dresden, Germany
| |
Collapse
|
22
|
Abstract
It is commonly believed that humans have a poor sense of smell compared to other mammalian species. However, this idea derives not from empirical studies of human olfaction but from a famous 19th-century anatomist's hypothesis that the evolution of human free will required a reduction in the proportional size of the brain's olfactory bulb. The human olfactory bulb is actually quite large in absolute terms and contains a similar number of neurons to that of other mammals. Moreover, humans have excellent olfactory abilities. We can detect and discriminate an extraordinary range of odors, we are more sensitive than rodents and dogs for some odors, we are capable of tracking odor trails, and our behavioral and affective states are influenced by our sense of smell.
Collapse
Affiliation(s)
- John P McGann
- Behavioral and Systems Neuroscience, Psychology Department, Rutgers University, 152 Frelinghuysen Road, Piscataway, NJ 08854, USA.
| |
Collapse
|
23
|
|
24
|
Yoo SJ, Lee JH, Kim SY, Son G, Kim JY, Cho B, Yu SW, Chang KA, Suh YH, Moon C. Differential spatial expression of peripheral olfactory neuron-derived BACE1 induces olfactory impairment by region-specific accumulation of β-amyloid oligomer. Cell Death Dis 2017; 8:e2977. [PMID: 28796251 PMCID: PMC5596540 DOI: 10.1038/cddis.2017.349] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 05/14/2017] [Accepted: 06/05/2017] [Indexed: 12/27/2022]
Abstract
Olfactory dysfunction is a common symptom associated with neurodegenerative diseases including Alzheimer's disease (AD). Although evidence exists to suggest that peripheral olfactory organs are involved in the olfactory dysfunction that accompanies AD pathology, the underlying mechanisms are not fully understood. As confirmed using behavioral tests, transgenic mice overexpressing a Swedish mutant form of human amyloid precursor proteins exhibited olfactory impairments prior to evidence of cognitive impairment. By measuring the expression of tyrosine hydroxylase, we observed that specific regions of the olfactory bulb (OB) in Tg2576 mice, specifically the ventral portion exhibited significant decreases in the number of dopaminergic neurons in the periglomerular regions from the early stage of AD. To confirm the direct linkage between these olfactory impairments and AD-related pathology, β-site amyloid precursor protein cleaving enzyme 1 (BACE1)-the initiating enzyme in Aβ genesis-and β-amyloid peptide (Aβ), hallmarks of AD were analyzed. We found that an increase in BACE1 expression coincided with an elevation of amyloid-β (Aβ) oligomers in the ventral region of OB. Moreover, olfactory epithelium (OE), in particular the ectoturbinate in which axons of olfactory sensory neurons (OSNs) have direct connections with the dendrites of mitral/tufted cells in the ventral part of OB, exhibited significant decreases in both thickness and cell number even at early stages. This result suggests that Aβ oligomer toxicity in the OE may have induced a decline in the number of OSNs and functional impairment of the olfactory system. We first demonstrated that disproportionate levels of regional damage in the peripheral olfactory system may be a specific symptom of AD with Aβ oligomer accumulation occurring prior to damage within the CNS. This regional damage in the olfactory system early in the progression of AD may be closely related to AD-related pathological abnormality and olfactory dysfunction found in AD patients.
Collapse
Affiliation(s)
- Seung-Jun Yoo
- Department of Brain and Cognitive Sciences, Graduate School, Daegu Gyeungbuk Institute of Science and Technology, Daegu, Korea
| | - Ji-Hye Lee
- Department of Brain and Cognitive Sciences, Graduate School, Daegu Gyeungbuk Institute of Science and Technology, Daegu, Korea
| | - So Yeun Kim
- Department of Brain and Cognitive Sciences, Graduate School, Daegu Gyeungbuk Institute of Science and Technology, Daegu, Korea
- Convergence Research Advanced Centre for Olfaction, Daegu Gyeungbuk Institute of Science and Technology, Daegu, Korea
| | - Gowoon Son
- Department of Brain and Cognitive Sciences, Graduate School, Daegu Gyeungbuk Institute of Science and Technology, Daegu, Korea
| | - Jae Yeon Kim
- Department of Brain and Cognitive Sciences, Graduate School, Daegu Gyeungbuk Institute of Science and Technology, Daegu, Korea
| | - Bongki Cho
- Department of Brain and Cognitive Sciences, Graduate School, Daegu Gyeungbuk Institute of Science and Technology, Daegu, Korea
- Convergence Research Advanced Centre for Olfaction, Daegu Gyeungbuk Institute of Science and Technology, Daegu, Korea
| | - Seong-Woon Yu
- Department of Brain and Cognitive Sciences, Graduate School, Daegu Gyeungbuk Institute of Science and Technology, Daegu, Korea
| | - Keun-A Chang
- Department of Pharmacology, School of Medicine, Gachon Medical School, Incheon, Korea
| | - Yoo-Hun Suh
- Department of Pharmacology, School of Medicine, Gachon Medical School, Incheon, Korea
| | - Cheil Moon
- Department of Brain and Cognitive Sciences, Graduate School, Daegu Gyeungbuk Institute of Science and Technology, Daegu, Korea
- Convergence Research Advanced Centre for Olfaction, Daegu Gyeungbuk Institute of Science and Technology, Daegu, Korea
| |
Collapse
|
25
|
Pothayee N, Cummings DM, Schoenfeld TJ, Dodd S, Cameron HA, Belluscio L, Koretsky AP. Magnetic resonance imaging of odorant activity-dependent migration of neural precursor cells and olfactory bulb growth. Neuroimage 2017; 158:232-241. [PMID: 28669915 DOI: 10.1016/j.neuroimage.2017.06.060] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 06/03/2017] [Accepted: 06/22/2017] [Indexed: 02/06/2023] Open
Abstract
Neural progenitors or neuroblasts are produced by precursor cells in the subventricular zone (SVZ) and migrate along the rostral migratory stream (RMS) to the olfactory bulbs (OB) throughout life. In the OB, these adult born neurons either die or replace existing olfactory interneurons, playing a critical role in the stabilization of OB circuitry. Although several aspects of the addition of new neurons into the OB have been studied, it is unclear whether long-distance activity from the OB can regulate the influx of migrating neuroblasts along the RMS. In this study, iron oxide-assisted MRI was used to track the migration of neuroblasts in combination with reversible naris occlusion to manipulate odorant-induced activity. It was found that decreasing olfactory activity led to a decrease in the rate of neuroblast migration along the RMS. Removal of the naris occlusion led to an increase in migratory rate back to control levels, indicating that olfactory activity has regulatory function on neuroblast migration in the RMS. Blocking odorant activity also led to an arrest in OB growth and re-opening the block led to a rapid re-growth returning the bulb size to control levels. Furthermore, pharmacogenetic elimination of the neuroblasts demonstrated that they were required for re-growth of the bulb following sensory deprivation. Together, these results show that sensory activity, neural migration and OB growth are tightly coupled in an interdependent manner.
Collapse
Affiliation(s)
- Nikorn Pothayee
- Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Diana M Cummings
- Developmental Neural Plasticity Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Timothy J Schoenfeld
- Section on Neuroplasticity, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
| | - Stephen Dodd
- Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Heather A Cameron
- Section on Neuroplasticity, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
| | - Leonardo Belluscio
- Developmental Neural Plasticity Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Alan P Koretsky
- Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.
| |
Collapse
|
26
|
Taalman H, Wallace C, Milev R. Olfactory Functioning and Depression: A Systematic Review. Front Psychiatry 2017; 8:190. [PMID: 29033860 PMCID: PMC5627007 DOI: 10.3389/fpsyt.2017.00190] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 09/15/2017] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Research has demonstrated a reduction in olfactory functioning in patients with schizophrenia. This research has led to examination of olfactory functioning in other mental disorders, such as depression. There is a great deal of variation in the results generated from such research, and it remains unclear as to how olfactory functioning is associated with or impacted by depression. METHOD The current review examined the literature in accordance with PRISMA guidelines in order to generate a better understanding of this relationship and to identify if and what aspects of olfactory processing are altered. Through examination of the available literature from the databases PubMed, Ovid Medline, CINAL, and PsychINFO, 15 manuscripts were selected to determine if there was a difference in olfactory processing-specifically central and peripheral processing-between depressed individuals and non-depressed controls. RESULTS The comparison of the 15 studies showed that the majority of studies (9/15, 60%) found a difference in overall olfactory functioning between depressed individuals and non-depressed controls (p < 0.05). LIMITATIONS There is still a lack of definitive conclusions due to variation of which olfactory process was altered. CONCLUSION Given the differences in the methodology and design of these studies, a possible solution that could eliminate the lack of clarity and reduce variation would be to adhere to a single, thorough methodology that examines and separates central and peripheral olfactory processing. Future research employing a uniform and validated methodology could provide more definitive conclusions as to how and if olfactory functioning is related depression.
Collapse
Affiliation(s)
- Hannah Taalman
- Centre for Neuroscience Studies, Queen's University, Kingston, ON, Canada
| | - Caroline Wallace
- Centre for Neuroscience Studies, Queen's University, Kingston, ON, Canada
| | - Roumen Milev
- Department of Psychiatry, Queen's University, Kingston, ON, Canada
| |
Collapse
|
27
|
Quast KB, Ung K, Froudarakis E, Huang L, Herman I, Addison AP, Ortiz-Guzman J, Cordiner K, Saggau P, Tolias AS, Arenkiel BR. Developmental broadening of inhibitory sensory maps. Nat Neurosci 2016; 20:189-199. [PMID: 28024159 DOI: 10.1038/nn.4467] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 11/18/2016] [Indexed: 12/14/2022]
Abstract
Sensory maps are created by networks of neuronal responses that vary with their anatomical position, such that representations of the external world are systematically and topographically organized in the brain. Current understanding from studying excitatory maps is that maps are sculpted and refined throughout development and/or through sensory experience. Investigating the mouse olfactory bulb, where ongoing neurogenesis continually supplies new inhibitory granule cells into existing circuitry, we isolated the development of sensory maps formed by inhibitory networks. Using in vivo calcium imaging of odor responses, we compared functional responses of both maturing and established granule cells. We found that, in contrast to the refinement observed for excitatory maps, inhibitory sensory maps became broader with maturation. However, like excitatory maps, inhibitory sensory maps are sensitive to experience. These data describe the development of an inhibitory sensory map as a network, highlighting the differences from previously described excitatory maps.
Collapse
Affiliation(s)
- Kathleen B Quast
- Department of Molecular &Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Kevin Ung
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, USA
| | | | - Longwen Huang
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA
| | - Isabella Herman
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, USA.,Medical Scientist Training Program, Baylor College of Medicine, Houston, Texas, USA
| | - Angela P Addison
- SMART Program, Baylor College of Medicine, Houston, Texas, USA.,University of St. Thomas, Houston, Texas, USA
| | - Joshua Ortiz-Guzman
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, USA
| | - Keith Cordiner
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA
| | - Peter Saggau
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA.,Allen Institute for Brain Science, Seattle, Washington, USA
| | - Andreas S Tolias
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA.,Department of Electrical and Computer Engineering, Rice University, Houston, Texas, USA
| | - Benjamin R Arenkiel
- Department of Molecular &Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, USA.,Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA.,Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas, USA
| |
Collapse
|
28
|
Longer latency of sensory response to intravenous odor injection predicts olfactory neural disorder. Sci Rep 2016; 6:35361. [PMID: 27734933 PMCID: PMC5062120 DOI: 10.1038/srep35361] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 09/28/2016] [Indexed: 11/08/2022] Open
Abstract
A near loss of smell may result from conductive and/or neural olfactory disorders. However, an olfactory test to selectively detect neural disorders has not been established. We investigated whether onset latency of sensory response to intravenous odor injection can detect neural disorders in humans and mice. We showed that longer preoperative onset latency of odor recognition to intravenous odor in patients with chronic rhinosinusitis predicted worse recovery of olfactory symptoms following sinus surgery. The onset latency of the olfactory sensory neuron (OSN) response to intravenous odor using synaptopHluorin signals from OSN axon terminals was delayed in mice with reduced numbers of OSNs (neural disorder) but not with increased mucus or blocked orthonasal pathways (conductive disorders). Moreover, the increase in onset latency correlated with the decrease in mature OSN numbers. Longer onset latency to intravenous odor injection is a useful biomarker for presence and severity of olfactory disorders with neural etiology.
Collapse
|
29
|
The olfactory bulbectomized rat as a model of depression: The hippocampal pathway. Behav Brain Res 2016; 317:562-575. [PMID: 27633561 DOI: 10.1016/j.bbr.2016.09.029] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 09/05/2016] [Accepted: 09/11/2016] [Indexed: 01/07/2023]
Abstract
In rodents, the removal of the olfactory bulbs (OBs), i.e. olfactory bulbectomy (OBX), results in numerous alterations in neurotransmitter, endocrine and immune systems, as well as behavioral changes, similar to those observed in depressed patients. Because the behavioral deficits induced in OBX animals are reversed after repeated administration of antidepressants, this is a model often used to test the effectiveness of putative antidepressant agents. Recent evidence suggests that OBX results in the dysfunction of various cellular processes within the hippocampus, including decreases in dentate gyrus neurogenesis, disruption in long-term potentiation in CA1 and CA3 subregions and neuronal atrophy in the CA1 subregion, along with downstream markers, all of which are consistent with abnormal neuronal activity in the hippocampus of clinically depressed populations. Moreover, repeated administration of novel natural and synthetic antidepressant compounds can improve certain aspects of depression-like behavior and hippocampal function. In an effort to bring together the existing literature, this review will focus on the mechanisms by which proposed pharmaceuticals impact hippocampal-dependent processes and behavior.
Collapse
|
30
|
Grier BD, Belluscio L, Cheetham CEJ. Olfactory Sensory Activity Modulates Microglial-Neuronal Interactions during Dopaminergic Cell Loss in the Olfactory Bulb. Front Cell Neurosci 2016; 10:178. [PMID: 27471450 PMCID: PMC4945633 DOI: 10.3389/fncel.2016.00178] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 06/30/2016] [Indexed: 12/02/2022] Open
Abstract
The mammalian olfactory bulb (OB) displays robust activity-dependent plasticity throughout life. Dopaminergic (DA) neurons in the glomerular layer (GL) of the OB are particularly plastic, with loss of sensory input rapidly reducing tyrosine hydroxylase (TH) expression and dopamine production, followed by a substantial reduction in DA neuron number. Here, we asked whether microglia participate in activity-dependent elimination of DA neurons in the mouse OB. Interestingly, we found a significant reduction in the number of both DA neurons and their synapses in the OB ipsilateral to the occluded naris (occluded OB) within just 7 days of sensory deprivation. Concomitantly, the volume of the occluded OB decreased, resulting in an increase in microglial density. Microglia in the occluded OB also adopted morphologies consistent with activation. Using in vivo 2-photon imaging and histological analysis we then showed that loss of olfactory input markedly altered microglial-neuronal interactions during the time that DA neurons are being eliminated: both microglial process motility and the frequency of wrapping of DA neuron somata by activated microglia increased significantly in the occluded OB. Furthermore, we found microglia in the occluded OB that had completely engulfed components of DA neurons. Together, our data provide evidence that loss of olfactory input modulates microglial-DA neuron interactions in the OB, thereby suggesting an important role for microglia in the activity-dependent elimination of DA neurons and their synapses.
Collapse
Affiliation(s)
- Bryce D Grier
- Developmental Neural Plasticity Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health Bethesda, MD, USA
| | - Leonardo Belluscio
- Developmental Neural Plasticity Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health Bethesda, MD, USA
| | - Claire E J Cheetham
- Developmental Neural Plasticity Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health Bethesda, MD, USA
| |
Collapse
|
31
|
Trimpe DM, Byrd-Jacobs CA. Patterns of olfactory bulb neurogenesis in the adult zebrafish are altered following reversible deafferentation. Neuroscience 2016; 331:134-47. [PMID: 27343831 DOI: 10.1016/j.neuroscience.2016.06.026] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 06/13/2016] [Accepted: 06/14/2016] [Indexed: 11/17/2022]
Abstract
Adult brain plasticity can be investigated using reversible methods that remove afferent innervation but allow return of sensory input. Repeated intranasal irrigation with Triton X-100 in adult zebrafish diminishes innervation to the olfactory bulb, resulting in a number of alterations in bulb structure and function, and cessation of the treatment allows for reinnervation and recovery. Using bromodeoxyuridine, Hu, and caspase-3 immunoreactivity we examined cell proliferation, differentiation, migration, and survival under conditions of acute and chronic deafferentation and reafferentation. Cell proliferation within the olfactory bulb was not influenced by acute or chronic deafferentation or reafferentation, but cell fate (including differentiation, migration, and/or survival of newly formed cells) was affected. We found that chronic deafferentation caused a bilateral increase in the number of newly formed cells that migrated into the bulb, although the amount of cell death of these new cells was significantly increased compared to untreated fish. Reafferentation also increased the number of newly formed cells migrating into both bulbs, suggesting that the deafferentation effect on cell fate was maintained. Reafferentation resulted in a decrease in newly formed cells that became neurons and, although death of newly formed cells was not altered from control levels, survival was reduced in relation to that seen in chronically deafferented fish. The potential effect of age on cell genesis was also examined. While the amount of cell migration into the olfactory bulbs was not affected by fish age, more of the newly formed cells became neurons in older fish. Younger fish displayed more cell death under conditions of chronic deafferentation. In sum, our results show that reversible deafferentation affects several aspects of cell fate, including cell differentiation, migration, and survival, and age of the fish influences the response to deafferentation.
Collapse
Affiliation(s)
- Darcy M Trimpe
- Department of Biological Sciences, Western Michigan University, 1903 W Michigan Ave, Kalamazoo, MI 49008-5410, USA.
| | - Christine A Byrd-Jacobs
- Department of Biological Sciences, Western Michigan University, 1903 W Michigan Ave, Kalamazoo, MI 49008-5410, USA.
| |
Collapse
|
32
|
Alarabawy RA, Eltomey MA, Shehata EM. Volumetric study of the olfactory bulb in patients with chronic rhinonasal sinusitis using MRI. THE EGYPTIAN JOURNAL OF RADIOLOGY AND NUCLEAR MEDICINE 2016. [DOI: 10.1016/j.ejrnm.2016.02.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
33
|
Bonzano S, Bovetti S, Gendusa C, Peretto P, De Marchis S. Adult Born Olfactory Bulb Dopaminergic Interneurons: Molecular Determinants and Experience-Dependent Plasticity. Front Neurosci 2016; 10:189. [PMID: 27199651 PMCID: PMC4858532 DOI: 10.3389/fnins.2016.00189] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 04/18/2016] [Indexed: 12/31/2022] Open
Abstract
The olfactory bulb (OB) is a highly plastic brain region involved in the early processing of olfactory information. A remarkably feature of the OB circuits in rodents is the constitutive integration of new neurons that takes place during adulthood. Newborn cells in the adult OB are mostly inhibitory interneurons belonging to chemically, morphologically and functionally heterogeneous types. Although there is general agreement that adult neurogenesis in the OB plays a key role in sensory information processing and olfaction-related plasticity, the contribution of each interneuron subtype to such functions is far to be elucidated. Here, we focus on the dopaminergic (DA) interneurons: we highlight recent findings about their morphological features and then describe the molecular factors required for the specification/differentiation and maintenance of the DA phenotype in adult born neurons. We also discuss dynamic changes of the DA interneuron population related to age, environmental stimuli and lesions, and their possible functional implications.
Collapse
Affiliation(s)
- Sara Bonzano
- Department of Life Sciences and Systems Biology, University of TurinTorino, Italy; Neuroscience Institute Cavalieri Ottolenghi, University of TurinOrbassano, Italy
| | - Serena Bovetti
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia Genova, Italy
| | - Claudio Gendusa
- Department of Life Sciences and Systems Biology, University of Turin Torino, Italy
| | - Paolo Peretto
- Department of Life Sciences and Systems Biology, University of TurinTorino, Italy; Neuroscience Institute Cavalieri Ottolenghi, University of TurinOrbassano, Italy
| | - Silvia De Marchis
- Department of Life Sciences and Systems Biology, University of TurinTorino, Italy; Neuroscience Institute Cavalieri Ottolenghi, University of TurinOrbassano, Italy
| |
Collapse
|
34
|
Barber CN, Coppola DM. Compensatory plasticity in the olfactory epithelium: age, timing, and reversibility. J Neurophysiol 2015; 114:2023-32. [PMID: 26269548 DOI: 10.1152/jn.00076.2015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 08/02/2015] [Indexed: 11/22/2022] Open
Abstract
Like other biological systems, olfaction responds "homeostatically" to enduring change in the stimulus environment. This adaptive mechanism, referred to as compensatory plasticity, has been studied almost exclusively in developing animals. Thus it is unknown if this phenomenon is limited to ontogenesis and irreversible, characteristics common to some other forms of plasticity. Here we explore the effects of odor deprivation on the adult mouse olfactory epithelium (OE) using nasal plugs to eliminate nasal airflow unilaterally. Plugs were in place for 2-6 wk after which electroolfactograms (EOGs) were recorded from the occluded and open sides of the nasal cavity. Mean EOG amplitudes were significantly greater on the occluded than on the open side. The duration of plugging did not affect the results, suggesting that maximal compensation occurs within 2 wk or less. The magnitude of the EOG difference between the open and occluded side in plugged mice was comparable to adults that had undergone surgical naris occlusion as neonates. When plugs were removed after 4 wk followed by 2 wk of recovery, mean EOG amplitudes were not significantly different between the always-open and previously plugged sides of the nasal cavity suggesting that this form of plasticity is reversible. Taken together, these results suggest that compensatory plasticity is a constitutive mechanism of olfactory receptor neurons that allows these cells to recalibrate their stimulus-response relationship to fit the statistics of their current odor environment.
Collapse
Affiliation(s)
- Casey N Barber
- Department of Biology, Randolph-Macon College, Ashland, Virginia
| | - David M Coppola
- Department of Biology, Randolph-Macon College, Ashland, Virginia
| |
Collapse
|
35
|
Luo J, Chen X, Pan YW, Lu S, Xia Z, Storm DR. The type 3 adenylyl cyclase is required for the survival and maturation of newly generated granule cells in the olfactory bulb. PLoS One 2015; 10:e0122057. [PMID: 25807252 PMCID: PMC4373939 DOI: 10.1371/journal.pone.0122057] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 02/06/2015] [Indexed: 01/14/2023] Open
Abstract
The type 3 adenylyl cyclase (AC3) is localized to olfactory cilia in the main olfactory epithelium (MOE) and primary cilia in the adult mouse brain. Although AC3 has been strongly implicated in odor perception and olfactory sensory neuron (OSN) targeting, its role in granule cells (GCs), the most abundant interneurons in the main olfactory bulb (MOB), remains largely unknown. Here, we report that the deletion of AC3 leads to a significant reduction in the size of the MOB as well as the level of adult neurogenesis. The cell proliferation and cell cycle in the subventricular zone (SVZ), however, are not suppressed in AC3-/- mice. Furthermore, AC3 deletion elevates the apoptosis of GCs and disrupts the maturation of newly formed GCs. Collectively, our results identify a fundamental role for AC3 in the development of adult-born GCs in the MOB.
Collapse
Affiliation(s)
- Jie Luo
- Department of Pharmacology, University of Washington, Seattle, Washington, United States of America
- College of Life Sciences, Wuhan University, Wuhan, Hubei, China
| | - Xuanmao Chen
- Department of Pharmacology, University of Washington, Seattle, Washington, United States of America
| | - Yung-Wei Pan
- Toxicology Program in the Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, United States of America
| | - Song Lu
- Toxicology Program in the Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, United States of America
| | - Zhengui Xia
- Toxicology Program in the Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, United States of America
| | - Daniel R. Storm
- Department of Pharmacology, University of Washington, Seattle, Washington, United States of America
- * E-mail:
| |
Collapse
|
36
|
Brunjes PC, Collins LN, Osterberg SK, Phillips AM. The mouse olfactory peduncle. 3. Development of neurons, glia, and centrifugal afferents. Front Neuroanat 2014; 8:44. [PMID: 24926238 PMCID: PMC4046489 DOI: 10.3389/fnana.2014.00044] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 05/19/2014] [Indexed: 11/14/2022] Open
Abstract
The present series of studies was designed to provide a general overview of the development of the region connecting the olfactory bulb to the forebrain. The olfactory peduncle (OP) contains several structures involved in processing odor information with the anterior olfactory nucleus (cortex) being the largest and most studied. Results indicate that considerable growth occurs in the peduncle from postnatal day (P)10–P20, with reduced expansion from P20 to P30. No evidence was found for the addition of new projection or interneurons during the postnatal period. GABAergic cells decreased in both number and density after P10. Glial populations exhibited different patterns of development, with astrocytes declining in density from P10 to P30, and both oligodendrocytes and microglia increasing through the interval. Myelination in the anterior commissure emerged between P11 and P14. Dense cholinergic innervation was observed at P10 and remained relatively stable through P30, while considerable maturation of serotonergic innervation occurred through the period. Unilateral naris occlusion from P1 to P30 resulted in about a 30% reduction in the size of the ipsilateral peduncle but few changes were observed on the contralateral side. The ipsilateral peduncle also exhibited higher densities of GAD67-containing interneurons and cholinergic fibers suggesting a delay in normal developmental pruning. Lower densities of interneurons expressing CCK, somatostatin, and NPY and in myelin basic protein staining were also observed. Understanding variations in developmental trajectories within the OP may be an important tool for unraveling the functions of the region.
Collapse
Affiliation(s)
- Peter C Brunjes
- Department of Psychology, University of Virginia, Charlottesville VA, USA
| | - Lindsay N Collins
- Department of Psychology, University of Virginia, Charlottesville VA, USA
| | | | - Adriana M Phillips
- Department of Psychology, University of Virginia, Charlottesville VA, USA
| |
Collapse
|
37
|
Oboti L, Peretto P. How neurogenesis finds its place in a hardwired sensory system. Front Neurosci 2014; 8:102. [PMID: 24847202 PMCID: PMC4023038 DOI: 10.3389/fnins.2014.00102] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 04/18/2014] [Indexed: 02/05/2023] Open
Abstract
So far most studies on adult neurogenesis aimed to unravel mechanisms and molecules regulating the integration of newly generated neurons in the mature brain parenchyma. The exceedingly abundant amount of results that followed, rather than being beneficial in the perspective of brain repair, provided a clear evidence that adult neurogenesis constitutes a necessary feature to the correct functioning of the hosting brain regions. In particular, the rodent olfactory system represents a privileged model to study how neuronal plasticity and neurogenesis interact with sensory functions. Until recently, the vomeronasal system (VNS) has been commonly described as being specialized in the detection of innate chemosignals. Accordingly, its circuitry has been considered necessarily stable, if not hard-wired, in order to allow stereotyped behavioral responses. However, both first and second order projections of the rodent VNS continuously change their synaptic connectivity due to ongoing postnatal and adult neurogenesis. How the functional integrity of a neuronal circuit is maintained while newborn neurons are continuously added—or lost—is a fundamental question for both basic and applied neuroscience. The VNS is proposed as an alternative model to answer such question. Hereby the underlying motivations will be reviewed.
Collapse
Affiliation(s)
- Livio Oboti
- Children's National Health System, Center for Neuroscience Research Washington, DC, USA
| | - Paolo Peretto
- Department of Life Sciences and Systems Biology, Neuroscience Institute Cavalieri Ottolenghi, University of Torino Orbassano, Italy
| |
Collapse
|
38
|
Croy I, Negoias S, Symmank A, Schellong J, Joraschky P, Hummel T. Reduced olfactory bulb volume in adults with a history of childhood maltreatment. Chem Senses 2014; 38:679-84. [PMID: 24051351 DOI: 10.1093/chemse/bjt037] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The human olfactory bulb (OB) is the first relay station of the olfactory pathway and may have the potential for postnatal neurogenesis in early childhood. In animals, chronic stress affects the OB and olfactory functioning. For humans, it has been shown that major depressive disorder is accompanied by reduced OB volume and reduced olfactory function. However, it is not clear if major stress in childhood development also affects olfactory functioning and OB volume in humans. OB volume was measured and olfactory function was tested in 17 depressive patients with and 10 without a history of severe childhood maltreatment (CM). CM patients exhibited a significantly reduced olfactory threshold and identification ability. The OB volume of the CM patients was significantly reduced to 80% of the non-CM patients. In conclusion, postnatal neurogenesis might be by reduced in CM, which may affect olfactory function of the brain in later life. Alternatively, a reduced OB volume may enhance psychological vulnerability in the presence of adverse childhood conditions although other areas not analyzed in this study may also be involved.
Collapse
Affiliation(s)
- Ilona Croy
- Department of Occupational and Environmental Medicine, University of Gothenburg, Medicinaregatan 16, 405 30 Gothenburg, Sweden.
| | | | | | | | | | | |
Collapse
|
39
|
Abraham NM, Vincis R, Lagier S, Rodriguez I, Carleton A. Long term functional plasticity of sensory inputs mediated by olfactory learning. eLife 2014; 3:e02109. [PMID: 24642413 PMCID: PMC3953949 DOI: 10.7554/elife.02109] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Sensory inputs are remarkably organized along all sensory pathways. While sensory representations are known to undergo plasticity at the higher levels of sensory pathways following peripheral lesions or sensory experience, less is known about the functional plasticity of peripheral inputs induced by learning. We addressed this question in the adult mouse olfactory system by combining odor discrimination studies with functional imaging of sensory input activity in awake mice. Here we show that associative learning, but not passive odor exposure, potentiates the strength of sensory inputs up to several weeks after the end of training. We conclude that experience-dependent plasticity can occur in the periphery of adult mouse olfactory system, which should improve odor detection and contribute towards accurate and fast odor discriminations. DOI:http://dx.doi.org/10.7554/eLife.02109.001 The mammalian brain is not static, but instead retains a significant degree of plasticity throughout an animal’s life. It is this plasticity that enables adults to learn new things, adjust to new environments and, to some degree, regain functions they have lost as a result of brain damage. However, information about the environment must first be detected and encoded by the senses. Odors, for example, activate specific receptors in the nose, and these in turn project to structures called glomeruli in a region of the brain known as the olfactory bulb. Each odor activates a unique combination of glomeruli, and the information contained within this ‘odor fingerprint’ is relayed via olfactory bulb neurons to the olfactory cortex. Now, Abraham et al. have revealed that the earliest stages of odor processing also show plasticity in adult animals. Two groups of mice were exposed to the same two odors: however, the first group was trained to discriminate between the odors to obtain a reward, whereas the second group was passively exposed to them. When both groups of mice were subsequently re-exposed to the odors, the trained group activated more glomeruli, more strongly, than a control group that had never encountered the odors before. By contrast, the responses of mice in the passively exposed group did not differ from those of a control group. Given that the response of glomeruli correlates with the ability of mice to discriminate between odors, these results suggest that trained animals would now be able to discriminate between the odors more easily than other mice. In other words, sensory plasticity ensures that stimuli that have been associatively learned with or without reward will be easier to detect should they be encountered again in the future. DOI:http://dx.doi.org/10.7554/eLife.02109.002
Collapse
Affiliation(s)
- Nixon M Abraham
- Department of Basic Neurosciences, School of Medicine, University of Geneva, Geneva, Switzerland
| | | | | | | | | |
Collapse
|
40
|
Neonatal olfactory bulbectomy enhances locomotor activity, exploratory behavior and binding of NMDA receptors in pre-pubertal rats. Neuroscience 2013; 259:84-93. [PMID: 24295633 DOI: 10.1016/j.neuroscience.2013.11.047] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 11/20/2013] [Accepted: 11/23/2013] [Indexed: 12/21/2022]
Abstract
In this study, we investigated the effect of neonatal olfactory bulbectomy (nOBX) on behavioral paradigms related to olfaction such as exploratory behavior, locomotor activity in a novel environment and social interaction. We also studied the effect of nOBX on the activity of the N-methyl-d-aspartate (NMDA) subtype of glutamate receptors during development. The behavioral effects of nOBX (postnatal day 7, PD7) were investigated in pre- (PD30) and post-pubertal (PD60) Wistar rats. NMDA receptor activity was measured with [(125)I]MK-801 in the brain regions associated with the olfactory circuitry. A significant increase in the novelty-induced locomotion was seen in the pre-pubertal nOBX rats. Although the locomotor effect was less marked than in pre-pubertal rats, the nOBX rats tested post-pubertally failed to habituate to the novel situation as quickly as the sham- and normal- controls. Pre-pubertally, the head-dipping behavior was enhanced in nOBX rats compared with sham-operated and normal controls, while normal exploratory behavior was observed between groups in adulthood. In contrast, social interaction was increased in post-pubertal animals that underwent nOBX. Both pre- and post-pubertal nOBX rats recovered olfaction. Interestingly, pre-pubertal rats showed a significant increase in the [(125)I]MK-801 binding in the piriform cortex, dorsal hippocampus, inner and outer layers of the frontal cortex and outer layer of the cingulate cortex. At post-pubertal age, no significant differences in [(125)I]MK-801 binding were observed between groups at any of the brain regions analyzed. These results suggest that nOBX produces pre-pubertal behavioral disturbances and NMDA receptor changes that are transitory with recovery of olfaction early in adulthood.
Collapse
|
41
|
A Dysfunctional Sense of Smell: The Irreversibility of Olfactory Evolution in Free-Living Pigs. Evol Biol 2013. [DOI: 10.1007/s11692-013-9262-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
|
42
|
Lötsch J, Schaeffeler E, Mittelbronn M, Winter S, Gudziol V, Schwarzacher SW, Hummel T, Doehring A, Schwab M, Ultsch A. Functional genomics suggest neurogenesis in the adult human olfactory bulb. Brain Struct Funct 2013; 219:1991-2000. [PMID: 23928746 DOI: 10.1007/s00429-013-0618-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 07/23/2013] [Indexed: 01/18/2023]
Abstract
The human olfactory bulb displays high morphologic dynamics changing its volume with olfactory function, which has been explained by active neurogenetic processes. Discussion continues whether the human olfactory bulb hosts a continuous turnover of neurons. We analyzed the transcriptome via RNA quantification of adult human olfactory bulbs and intersected the set of expressed transcriptomic genes with independently available proteomic expression data. To obtain a functional genomic perspective, this intersection was analyzed for higher-level organization of gene products into biological pathways established in the gene ontology database. We report that a fifth of genes expressed in adult human olfactory bulbs serve functions of nervous system or neuron development, half of them functionally converging to axonogenesis but no other non-neurogenetic biological processes. Other genes were expectedly involved in signal transmission and response to chemical stimuli. This provides a novel, functional genomics perspective supporting the existence of neurogenesis in the adult human olfactory bulb.
Collapse
Affiliation(s)
- Jörn Lötsch
- Institute of Clinical Pharmacology, Goethe-University, Theodor Stern Kai 7, 60590, Frankfurt am Main, Germany,
| | | | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Díaz D, Gómez C, Muñoz-Castañeda R, Baltanás F, Alonso JR, Weruaga E. The Olfactory System as a Puzzle: Playing With Its Pieces. Anat Rec (Hoboken) 2013; 296:1383-400. [DOI: 10.1002/ar.22748] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- D. Díaz
- Laboratory of Neuronal Plasticity and Neurorepair; Institute for Neuroscience of Castile and Leon (INCyL), Universidad de Salamanca; Salamanca Spain
- Area of Gene and Cell Therapy; Institute of Biomedical Research of Salamanca, IBSAL; Salamanca Spain
| | - C. Gómez
- Laboratory of Neuronal Plasticity and Neurorepair; Institute for Neuroscience of Castile and Leon (INCyL), Universidad de Salamanca; Salamanca Spain
- Institute for Molecular and Cell Biology of the Cancer, IBMCC, CSIC-Universidad de Salamanca; Salamanca Spain
| | - R. Muñoz-Castañeda
- Laboratory of Neuronal Plasticity and Neurorepair; Institute for Neuroscience of Castile and Leon (INCyL), Universidad de Salamanca; Salamanca Spain
- Area of Gene and Cell Therapy; Institute of Biomedical Research of Salamanca, IBSAL; Salamanca Spain
| | - F. Baltanás
- Laboratory of Neuronal Plasticity and Neurorepair; Institute for Neuroscience of Castile and Leon (INCyL), Universidad de Salamanca; Salamanca Spain
- Institute for Molecular and Cell Biology of the Cancer, IBMCC, CSIC-Universidad de Salamanca; Salamanca Spain
| | - J. R. Alonso
- Laboratory of Neuronal Plasticity and Neurorepair; Institute for Neuroscience of Castile and Leon (INCyL), Universidad de Salamanca; Salamanca Spain
- Area of Gene and Cell Therapy; Institute of Biomedical Research of Salamanca, IBSAL; Salamanca Spain
- Institute for High Research, Universidad de Tarapacá; Arica Chile
| | - E. Weruaga
- Laboratory of Neuronal Plasticity and Neurorepair; Institute for Neuroscience of Castile and Leon (INCyL), Universidad de Salamanca; Salamanca Spain
- Area of Gene and Cell Therapy; Institute of Biomedical Research of Salamanca, IBSAL; Salamanca Spain
| |
Collapse
|
44
|
Morrison GL, Fontaine CJ, Harley CW, Yuan Q. A role for the anterior piriform cortex in early odor preference learning: evidence for multiple olfactory learning structures in the rat pup. J Neurophysiol 2013; 110:141-52. [PMID: 23576704 DOI: 10.1152/jn.00072.2013] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
cFos activation in the anterior piriform cortex (aPC) occurs in early odor preference learning in rat pups (Roth and Sullivan 2005). Here we provide evidence that the pairing of odor as a conditioned stimulus and β-adrenergic activation in the aPC as an unconditioned stimulus generates early odor preference learning. β-Adrenergic blockade in the aPC prevents normal preference learning. Enhancement of aPC cAMP response element-binding protein (CREB) phosphorylation in trained hemispheres is consistent with a role for this cascade in early odor preference learning in the aPC. In vitro experiments suggested theta-burst-mediated long-term potentiation (LTP) at the lateral olfactory tract (LOT) to aPC synapse depends on N-methyl-D-aspartate (NMDA) receptors and can be significantly enhanced by β-adrenoceptor activation, which causes increased glutamate release from LOT synapses during LTP induction. NMDA receptors in aPC are also shown to be critical for the acquisition, but not expression, of odor preference learning, as would be predicted if they mediate initial β-adrenoceptor-promoted aPC plasticity. Ex vivo experiments 3 and 24 h after odor preference training reveal an enhanced LOT-aPC field excitatory postsynaptic potential (EPSP). At 3 h both presynaptic and postsynaptic potentiations support EPSP enhancement while at 24 h only postsynaptic potentiation is seen. LOT-LTP in aPC is excluded by odor preference training. Taken together with earlier work on the role of the olfactory bulb in early odor preference learning, these outcomes suggest early odor preference learning is normally supported by and requires multiple plastic changes at least at two levels of olfactory circuitry.
Collapse
Affiliation(s)
- Gillian L Morrison
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
| | | | | | | |
Collapse
|
45
|
Gribaudo S, Bovetti S, Friard O, Denorme M, Oboti L, Fasolo A, De Marchis S. Transitory and activity-dependent expression of neurogranin in olfactory bulb tufted cells during mouse postnatal development. J Comp Neurol 2013; 520:3055-69. [PMID: 22592880 DOI: 10.1002/cne.23150] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Neurogranin (Ng) is a brain-specific postsynaptic calmodulin-binding protein involved in synaptic activity-dependent plasticity. In the adult olfactory bulb (OB), Ng is expressed by a large population of GABAergic interneurons in the granule cell layer. We show here that, during postnatal development, Ng is also expressed by OB neurons in the superficial external plexiform layer (sEPL) and glomerular layer (GL). These Ng-positive neurons display morphological and neurochemical features of superficial and external tufted cells. Ng expression in these cells is transient during OB development: few elements express Ng at postnatal day (P) 5, increasing in number and reaching a peak at P10, then progressively decreasing. At P30, Ng is rarely detectable in these neurons. Ng expression in developing tufted cells is also modulated at the cellular level: at earlier stages, Ng labeling is distributed throughout the cell body and dendritic arborization in the GL, but, at P20, when the glomerular circuits are fully matured, Ng becomes restricted to the soma and proximal portion of tufted cell apical dendrites. We show that olfactory deprivation at early postnatal stages induces a strong increase in Ng-positive tufted cells from P10 to P20, whereas no changes have been observed following olfactory deprivation in adult mice. These findings demonstrate that Ng expression in sEPL-GL is restricted to developmental stages and indicate its activity-dependent regulation in a time window critical for glomerular circuit development, suggesting a role for Ng in maturation and dendritic remodeling of tufted cells.
Collapse
Affiliation(s)
- S Gribaudo
- Department of Life Sciences and Systems Biology, University of Turin, 10123 Turin, Italy.
| | | | | | | | | | | | | |
Collapse
|
46
|
Liu H, Lu M, Guthrie KM. Anterograde trafficking of neurotrophin-3 in the adult olfactory system in vivo. Exp Neurol 2012; 241:125-37. [PMID: 23261763 DOI: 10.1016/j.expneurol.2012.12.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Revised: 12/04/2012] [Accepted: 12/13/2012] [Indexed: 12/12/2022]
Abstract
The olfactory system continuously incorporates new neurons into functional circuits throughout life. Axons from olfactory sensory neurons (OSNs) in the nasal cavity synapse on mitral, tufted and periglomerular (PG) cells in the main olfactory bulb, and low levels of turnover within the OSN population results in ingrowth of new axons under normal physiological conditions. Subpopulations of bulb interneurons are continually eliminated by apoptosis, and are replaced by new neurons derived from progenitors in the adult forebrain subventricular zone. Integration of new neurons, including PG cells that are contacted by sensory axons, leads to ongoing reorganization of adult olfactory bulb circuits. The mechanisms regulating this adaptive structural plasticity are not all known, but the process is reminiscent of early nervous system development. Neurotrophic factors have well-established roles in controlling neuronal survival and connectivity during development, leading to speculation that trophic interactions between OSNs and their target bulb neurons may mediate some of these same processes in adults. A number of different trophic factors and their cognate receptors are expressed in the adult olfactory pathway. Neurotrophin-3 (NT3) is among these, as reflected by beta-galactosidase expression in transgenic reporter mice expressing lacZ under the NT3 promoter. Using a combination of approaches, including immunocytochemistry, real-time PCR of laser-captured RNA, and adenovirus-mediated gene transfer of NT3 fusion peptides in vivo, we demonstrate that OSNs express and anterogradely transport NT3 to the olfactory bulb. We additionally observe that in mice treated with adenovirus encoding NT3 tagged with hemagglutinin (HA), a subset of bulb neurons expressing the TrkC neurotrophin receptor are immunoreactive for HA, suggesting their acquisition of the fusion peptide from infected sensory neurons. Our results therefore provide evidence that OSNs may serve as an afferent source of trophic signals for the adult mouse olfactory bulb.
Collapse
Affiliation(s)
- Huan Liu
- Department of Basic Biomedical Science, College of Medicine, Florida Atlantic University, Boca Raton, FL 33431, USA
| | | | | |
Collapse
|
47
|
Abstract
The study aimed to investigate the volume of the olfactory bulb in smokers. Specifically, we wanted to see whether environmental influences may exert a negative influence on OB structure. Twenty-one smokers and 59 non-smokers, matched for age and sex, underwent olfactory testing by means of the Sniffin' Sticks testing device (measurement of odor threshold and identification abilities). In addition, they underwent an MR scan with 2-mm-thick T2-weighted fast spin-echo images without interslice gap in the coronal plane covering the anterior and middle segments of the base of the skull. Olfactory function was not different between the 2 groups; however, olfactory bulb volumes were smaller in smokers than in non-smokers (p = 0.006). The deficit seen at the level of the OB did not correlate with the duration of smoking. The current data indicate that smoking may have a negative effect on the olfactory system before this becomes obvious in terms of a decreased olfactory function.
Collapse
|
48
|
Kass MD, Pottackal J, Turkel DJ, McGann JP. Changes in the neural representation of odorants after olfactory deprivation in the adult mouse olfactory bulb. Chem Senses 2012; 38:77-89. [PMID: 23125347 DOI: 10.1093/chemse/bjs081] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Olfactory sensory deprivation during development has been shown to induce significant alterations in the neurophysiology of olfactory receptor neurons (ORNs), the primary sensory inputs to the brain's olfactory bulb. Deprivation has also been shown to alter the neurochemistry of the adult olfactory system, but the physiological consequences of these changes are poorly understood. Here we used in vivo synaptopHluorin (spH) imaging to visualize odorant-evoked neurotransmitter release from ORNs in adult transgenic mice that underwent 4 weeks of unilateral olfactory deprivation. Deprivation reduced odorant-evoked spH signals compared with sham-occluded mice. Unexpectedly, this reduction was equivalent between ORNs on the open and plugged sides. Changes in odorant selectivity of glomerular subpopulations of ORNs were also observed, but only in ORNs on the open side of deprived mice. These results suggest that naris occlusion in adult mice produces substantial changes in primary olfactory processing which may reflect not only the decrease in olfactory stimulation on the occluded side but also the alteration of response properties on the intact side. We also observed a modest effect of true sham occlusions that included noseplug insertion and removal, suggesting that conventional noseplug techniques may have physiological effects independent of deprivation per se and thus require more careful controls than has been previously appreciated.
Collapse
Affiliation(s)
- Marley D Kass
- Behavioral and Systems Neuroscience Section, Department of Psychology, Rutgers, The State University of New Jersey, USA
| | | | | | | |
Collapse
|
49
|
Kato Y, Kaneko N, Sawada M, Ito K, Arakawa S, Murakami S, Sawamoto K. A subtype-specific critical period for neurogenesis in the postnatal development of mouse olfactory glomeruli. PLoS One 2012; 7:e48431. [PMID: 23133633 PMCID: PMC3486849 DOI: 10.1371/journal.pone.0048431] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Accepted: 09/25/2012] [Indexed: 11/25/2022] Open
Abstract
Sensory input is essential for the normal development of sensory centers in the brain, such as the somatosensory, visual, auditory, and olfactory systems. Visual deprivation during a specific developmental stage, called the critical period, results in severe and irreversible functional impairments in the primary visual cortex. Olfactory deprivation in the early postnatal period also causes significant developmental defects in the olfactory bulb, the primary center for olfaction. Olfactory bulb interneurons are continuously generated from neural stem cells in the ventricular-subventricular zone, suggesting that the olfactory system has plasticity even in adulthood. Here, we investigated the effect of transient neonatal olfactory deprivation on the addition of interneurons to the glomerular layer of the adult mouse olfactory bulb. We found that the addition of one subtype of interneurons was persistently inhibited even after reopening the naris. BrdU pulse-chase experiments revealed that the neonatal olfactory deprivation predominantly affected an early phase in the maturation of this neuronal subtype in the olfactory bulb. Subjecting the mice to odor stimulation for 6 weeks after naris reopening resulted in significant recovery from the histological and functional defects caused by the olfactory deprivation. These results suggest that a subtype-specific critical period exists for olfactory bulb neurogenesis, but that this period is less strict and more plastic compared with the critical periods for other systems. This study provides new insights into the mechanisms of postnatal neurogenesis and a biological basis for the therapeutic effect of olfactory training.
Collapse
Affiliation(s)
- Yasuko Kato
- Department of Developmental and Regenerative Biology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan
- Dpartment of Neuro-otolaryngology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan
| | - Naoko Kaneko
- Department of Developmental and Regenerative Biology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan
| | - Masato Sawada
- Department of Developmental and Regenerative Biology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan
| | - Keishi Ito
- Department of Developmental and Regenerative Biology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan
| | - Sousuke Arakawa
- Department of Developmental and Regenerative Biology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan
| | - Shingo Murakami
- Dpartment of Neuro-otolaryngology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan
| | - Kazunobu Sawamoto
- Department of Developmental and Regenerative Biology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan
- * E-mail:
| |
Collapse
|
50
|
Studies of olfactory system neural plasticity: the contribution of the unilateral naris occlusion technique. Neural Plast 2012; 2012:351752. [PMID: 22690343 PMCID: PMC3368527 DOI: 10.1155/2012/351752] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 03/01/2012] [Accepted: 03/19/2012] [Indexed: 01/18/2023] Open
Abstract
Unilateral naris occlusion has long been the method of choice for effecting stimulus deprivation in studies of olfactory plasticity. A significant body of literature speaks to the myriad consequences of this manipulation on the ipsilateral olfactory pathway. Early experiments emphasized naris occlusion's deleterious and age-critical effects. More recent studies have focused on life-long vulnerability, particularly on neurogenesis, and compensatory responses to deprivation. Despite the abundance of empirical data, a theoretical framework in which to understand the many sequelae of naris occlusion on olfaction has been elusive. This paper focuses on recent data, new theories, and underappreciated caveats related to the use of this technique in studies of olfactory plasticity.
Collapse
|