1
|
Liu Y, Chen J, Li Q, Guo YX, Chen YJ, Zhao YJ. Locus coeruleus activation contributes to masseter muscle overactivity induced by chronic restraint stress in mice. Neuroreport 2024; 35:763-770. [PMID: 38935079 PMCID: PMC11236267 DOI: 10.1097/wnr.0000000000002058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2024]
Abstract
It is commonly accepted that exposure to stress may cause overactivity in the orofacial muscles, leading to consistent muscle pain, which is the main symptom of temporomandibular disorders. The central neural mechanism underlying this process, however, remains unclear. The locus coeruleus is considered to play an important role in stress-related behavioral changes. Therefore, the present study was designed to examine the role of locus coeruleus neurons in masseter overactivity induced by stress. C57BL/6 mice were subjected to chronic restraint stress for 14 days to establish an animal model. The behavioral changes and the electromyography of the masseter muscle in mice were measured. The expression of Fos in locus coeruleus was observed by immunofluorescence staining to assess neuronal activation. A chemogenetic test was used to inhibit locus coeruleus neuronal activity, and the behavioral changes and electromyography of the masseter muscle were observed again. The results exhibited that chronic restraint stress could induce anxiety-like behavior, overactivity of the masseter muscle, and significant activation of locus coeruleus neurons in mice. Furthermore, inhibition of noradrenergic neuron activity within the locus coeruleus could alleviate stress-induced anxiety behavior and masseter muscle overactivity. Activation of noradrenergic neurons in locus coeruleus induced by stress may be one of the central regulatory mechanisms for stress-induced anxiety-like behaviors and overactivity of masseter muscles.
Collapse
Affiliation(s)
- Yang Liu
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, National Clinical Research Center for Oral Diseases, Shaanxi International Joint Research Center for Oral Diseases, Department of General Dentistry and Emergency, School of Stomatology, The Fourth Military Medical University
| | - Ji Chen
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, National Clinical Research Center for Oral Diseases, Shaanxi International Joint Research Center for Oral Diseases, Center for Tissue Engineering, School of Stomatology, The Fourth Military Medical University
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, National Clinical Research Center for Oral Diseases, Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Department of Oral Implantology, School of Stomatology, The Fourth Military Medical University, Xi'an, China
| | - Qiang Li
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, National Clinical Research Center for Oral Diseases, Shaanxi International Joint Research Center for Oral Diseases, Department of General Dentistry and Emergency, School of Stomatology, The Fourth Military Medical University
| | - Yan-Xia Guo
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, National Clinical Research Center for Oral Diseases, Shaanxi International Joint Research Center for Oral Diseases, Department of General Dentistry and Emergency, School of Stomatology, The Fourth Military Medical University
| | - Yong-Jin Chen
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, National Clinical Research Center for Oral Diseases, Shaanxi International Joint Research Center for Oral Diseases, Department of General Dentistry and Emergency, School of Stomatology, The Fourth Military Medical University
| | - Ya-Juan Zhao
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, National Clinical Research Center for Oral Diseases, Shaanxi International Joint Research Center for Oral Diseases, Department of General Dentistry and Emergency, School of Stomatology, The Fourth Military Medical University
| |
Collapse
|
2
|
Kang Y, Toyoda H, Saito M. Search for unknown neural link between the masticatory and cognitive brain systems to clarify the involvement of its impairment in the pathogenesis of Alzheimer's disease. Front Cell Neurosci 2024; 18:1425645. [PMID: 38994328 PMCID: PMC11236757 DOI: 10.3389/fncel.2024.1425645] [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: 04/30/2024] [Accepted: 06/12/2024] [Indexed: 07/13/2024] Open
Abstract
Brain degenerations in sporadic Alzheimer's disease (AD) are observed earliest in the locus coeruleus (LC), a population of noradrenergic neurons, in which hyperphosphorylated tau protein expression and β-amyloid (Aβ) accumulation begin. Along with this, similar changes occur in the basal forebrain cholinergic neurons, such as the nucleus basalis of Meynert. Neuronal degeneration of the two neuronal nuclei leads to a decrease in neurotrophic factors such as brain-derived neurotrophic factor (BDNF) in the hippocampus and cerebral cortex, which results in the accumulation of Aβ and hyperphosphorylated tau protein and ultimately causes neuronal cell death in those cortices. On the other hand, a large number of epidemiological studies have shown that tooth loss or masticatory dysfunction is a risk factor for dementia including AD, and numerous studies using experimental animals have also shown that masticatory dysfunction causes brain degeneration in the basal forebrain, hippocampus, and cerebral cortex similar to those observed in human AD, and that learning and memory functions are impaired accordingly. However, it remains unclear how masticatory dysfunction can induce such brain degeneration similar to AD, and the neural mechanism linking the trigeminal nervous system responsible for mastication and the cognitive and memory brain system remains unknown. In this review paper, we provide clues to the search for such "missing link" by discussing the embryological, anatomical, and physiological relationship between LC and its laterally adjoining mesencephalic trigeminal nucleus which plays a central role in the masticatory functions.
Collapse
Affiliation(s)
- Youngnam Kang
- Department of Behavioral Physiology, Osaka University Graduate School of Human Sciences, Osaka, Japan
| | - Hiroki Toyoda
- Department of Oral Physiology, Osaka University Graduate School of Dentistry, Osaka, Japan
| | - Mitsuru Saito
- Department of Oral Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| |
Collapse
|
3
|
Wang N, Warren S, May PJ. Mesencephalic trigeminal neuron dendritic structures in the macaque. Anat Rec (Hoboken) 2024. [PMID: 38924671 DOI: 10.1002/ar.25523] [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: 12/11/2023] [Revised: 05/10/2024] [Accepted: 05/30/2024] [Indexed: 06/28/2024]
Abstract
It is presumed that the unusual central location of mesencephalic trigeminal neurons is a specialization that allows them to receive synaptic input. However, relatively few synaptic terminals were observed on the somata of mesencephalic trigeminal neurons in macaque monkeys via electron microscopy. This leaves the question of dendritic synaptic terminals open. Unlike the pseudounipolar neurons found in the trigeminal ganglion, some mesencephalic trigeminal neurons have been reported to be multipolar cells exhibiting a number of dendritic processes in non-primate species. To examine whether this morphological feature was also present in macaque monkeys, we retrogradely filled these cells with biotinylated dextran amine by injecting it into the trigeminal nerve entry zone. A portion of the mesencephalic trigeminal neurons exhibited short, poorly branched, dendritic processes. They also exhibited very fine, short processes believed to be somatic spines. Thus, primate trigeminal mesencephalic neurons appear to have specializations aimed at increasing the membrane surface area available for synaptic input.
Collapse
Affiliation(s)
- Niping Wang
- Department of Periodontics and Preventive Sciences, School of Dentistry, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Susan Warren
- Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Paul J May
- Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, Mississippi, USA
| |
Collapse
|
4
|
Ochi S, Yamada K, Saito T, Saido TC, Iinuma M, Azuma K, Kubo KY. Effects of early tooth loss on chronic stress and progression of neuropathogenesis of Alzheimer's disease in adult Alzheimer's model AppNL-G-F mice. Front Aging Neurosci 2024; 16:1361847. [PMID: 38469162 PMCID: PMC10925668 DOI: 10.3389/fnagi.2024.1361847] [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: 12/27/2023] [Accepted: 02/12/2024] [Indexed: 03/13/2024] Open
Abstract
Introduction Alzheimer's disease (AD), the most common neurodegenerative disease, is characterized by accumulated amyloid-β (Aβ) plaques, aggregated phosphorylated tau protein, gliosis-associated neuroinflammation, synaptic dysfunction, and cognitive impairment. Many cohort studies indicate that tooth loss is a risk factor for AD. The detailed mechanisms underlying the association between AD and tooth loss, however, are not yet fully understood. Methods We explored the involvement of early tooth loss in the neuropathogenesis of the adult AppNL-G-F mouse AD model. The maxillary molars were extracted bilaterally in 1-month-old male mice soon after tooth eruption. Results Plasma corticosterone levels were increased and spatial learning memory was impaired in these mice at 6 months of age. The cerebral cortex and hippocampus of AD mice with extracted teeth showed an increased accumulation of Aβ plaques and phosphorylated tau proteins, and increased secretion of the proinflammatory cytokines, including interleukin 1β (IL-1β) and tumor necrosis factor α (TNF-α), accompanied by an increased number of microglia and astrocytes, and decreased synaptophysin expression. AD mice with extracted teeth also had a shorter lifespan than the control mice. Discussion These findings revealed that long-term tooth loss is a chronic stressor, activating the recruitment of microglia and astrocytes; exacerbating neuroinflammation, Aβ deposition, phosphorylated tau accumulation, and synaptic dysfunction; and leading to spatial learning and memory impairments in AD model mice.
Collapse
Affiliation(s)
- Suzuko Ochi
- Department of Pediatric Dentistry, Asahi University School of Dentistry, Mizuho, Japan
| | - Kumiko Yamada
- Department of Health and Nutrition, Faculty of Health Science, Nagoya Women's University, Nagoya, Japan
| | - Takashi Saito
- Department of Neurocognitive Science, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Takaomi C Saido
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, Wako, Japan
| | - Mitsuo Iinuma
- Department of Pediatric Dentistry, Asahi University School of Dentistry, Mizuho, Japan
| | - Kagaku Azuma
- Department of Anatomy, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Kin-Ya Kubo
- Graduate School of Human Life Science, Nagoya Women's University, Nagoya, Japan
| |
Collapse
|
5
|
Wang N, May PJ. The ultrastructure of macaque mesencephalic trigeminal nucleus neurons. Exp Brain Res 2024; 242:295-307. [PMID: 38040856 DOI: 10.1007/s00221-023-06746-y] [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: 09/29/2023] [Accepted: 11/06/2023] [Indexed: 12/03/2023]
Abstract
Primary afferents originating from the mesencephalic trigeminal nucleus provide the main source of proprioceptive information guiding mastication, and thus represent an important component of this critical function. Unlike those of other primary afferents, their cell bodies lie within the central nervous system. It is believed that this unusual central location allows them to be regulated by synaptic input. In this study, we explored the ultrastructure of macaque mesencephalic trigeminal nucleus neurons to determine the presence and nature of this synaptic input in a primate. We first confirmed the location of macaque mesencephalic trigeminal neurons by retrograde labeling from the masticatory muscles. Since the labeled neurons were by far the largest cells located at the edge of the periaqueductal gray, we could undertake sampling for electron microscopy based on soma size. Ultrastructurally, mesencephalic trigeminal neurons had very large somata with euchromatic nuclei that sometimes displayed deeply indented nuclear membranes. Terminal profiles with varied vesicle characteristics and synaptic density thicknesses were found in contact with either their somatic plasma membranes or somatic spines. However, in contradistinction to other, much smaller, somata in the region, the plasma membranes of the mesencephalic trigeminal somata had only a few synaptic contacts. They did extend numerous somatic spines of various lengths into the neuropil, but most of these also lacked synaptic contact. The observed ultrastructural organization indicates that macaque trigeminal mesencephalic neurons do receive synaptic contacts, but despite their central location, they only avail themselves of very limited input.
Collapse
Affiliation(s)
- Niping Wang
- Department of Periodontics and Preventive Sciences, School of Dentistry, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA.
| | - Paul J May
- Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, MS, 39216, USA
| |
Collapse
|
6
|
Zhang ZJ, Zhang SY, Yang XJ, Qin ZS, Xu FQ, Jin GX, Hou XB, Liu Y, Cai JF, Xiao HB, Wong YK, Zheng Y, Shi L, Zhang JN, Zhao YY, Xiao X, Zhang LL, Jiao Y, Wang Y, He JK, Chen GB, Rong PJ. Transcutaneous electrical cranial-auricular acupoint stimulation versus escitalopram for mild-to-moderate depression: An assessor-blinded, randomized, non-inferiority trial. Psychiatry Clin Neurosci 2023; 77:168-177. [PMID: 36445151 DOI: 10.1111/pcn.13512] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 11/15/2022] [Accepted: 11/21/2022] [Indexed: 12/03/2022]
Abstract
AIM Transcutaneous electrical cranial-auricular acupoint stimulation (TECAS) is a novel non-invasive therapy that stimulates acupoints innervated by the trigeminal and auricular vagus nerves. An assessor-blinded, randomized, non-inferiority trial was designed to compare the efficacy of TECAS and escitalopram in mild-to-moderate major depressive disorder. METHODS 468 participants received two TECAS sessions per day at home (n = 233) or approximately 10-13 mg/day escitalopram (n = 235) for 8 weeks plus 4-week follow-up. The primary outcome was clinical response, defined as a baseline-to-endpoint ≥50% reduction in Montgomery-Åsberg Depression Rating Scale (MADRS) score. Secondary outcomes included remission rate, changes in the severity of depression, anxiety, sleep and life quality. RESULTS The response rate was 66.4% on TECAS and 63.2% on escitalopram with a 3.2% difference (95% confidence interval [CI], -5.9% to 12.9%) in intention-to-treat analysis, and 68.5% versus 66.2% with a 2.3% difference (95% CI, -6.9% to 11.4%) in per-protocol analysis. The lower limit of 95% CI of the differences fell within the prespecified non-inferiority margin of -10% (P ≤ 0.004 for non-inferiority). Most secondary outcomes did not differ between the two groups. TECAS-treated participants who experienced psychological trauma displayed a markedly greater response than those without traumatic experience (81.3% vs 62.1%, P = 0.013). TECAS caused much fewer adverse events than escitalopram. CONCLUSIONS TECAS was comparable to escitalopram in improving depression and related symptoms, with high acceptability, better safety profile, and particular efficacy in reducing trauma-associated depression. It could serve an effective portable therapy for mild-to-moderate depression.
Collapse
Affiliation(s)
- Zhang-Jin Zhang
- Department of Chinese Medicine, the University of Hong Kong-Shenzhen Hospital (HKU-SZH), Shenzhen, China.,School of Chinese Medicine, LKS Faculty of Medicine, the University of Hong Kong, Hong Kong, China
| | - Shui-Yan Zhang
- Department of Chinese Medicine, the University of Hong Kong-Shenzhen Hospital (HKU-SZH), Shenzhen, China
| | - Xin-Jing Yang
- Department of Chinese Medicine, the University of Hong Kong-Shenzhen Hospital (HKU-SZH), Shenzhen, China.,School of Chinese Medicine, LKS Faculty of Medicine, the University of Hong Kong, Hong Kong, China
| | - Zong-Shi Qin
- Department of Chinese Medicine, the University of Hong Kong-Shenzhen Hospital (HKU-SZH), Shenzhen, China.,School of Chinese Medicine, LKS Faculty of Medicine, the University of Hong Kong, Hong Kong, China
| | - Feng-Quan Xu
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences (CACMS), Beijing, China
| | - Gui-Xing Jin
- The First Hospital of Hebei Medical University, Shijiazhuang, China
| | - Xiao-Bing Hou
- Beijing First Hospital of Integrated Chinese and Western Medicine, Beijing, China
| | - Yong Liu
- The Affiliated Traditional Chinese Medicine Hospital of Southwest Medical University, Luzhou, Sichuan, China
| | - Ji-Fu Cai
- Department of Neurology, the University of Hong Kong-Shenzhen Hospital (HKU-SZH), Shenzhen, China
| | - Hai-Bing Xiao
- Department of Neurology, the University of Hong Kong-Shenzhen Hospital (HKU-SZH), Shenzhen, China
| | - Yat Kwan Wong
- Department of Chinese Medicine, the University of Hong Kong-Shenzhen Hospital (HKU-SZH), Shenzhen, China.,School of Chinese Medicine, LKS Faculty of Medicine, the University of Hong Kong, Hong Kong, China
| | - Yu Zheng
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences (CACMS), Beijing, China
| | - Lei Shi
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences (CACMS), Beijing, China
| | - Jin-Niu Zhang
- The First Hospital of Hebei Medical University, Shijiazhuang, China
| | - Yuan-Yuan Zhao
- The First Hospital of Hebei Medical University, Shijiazhuang, China
| | - Xue Xiao
- Beijing First Hospital of Integrated Chinese and Western Medicine, Beijing, China
| | - Liu-Lu Zhang
- The Affiliated Traditional Chinese Medicine Hospital of Southwest Medical University, Luzhou, Sichuan, China
| | - Yue Jiao
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences (CACMS), Beijing, China.,Department of TCM, Tsinghua University Hospital Beijing, Beijing, China
| | - Yu Wang
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences (CACMS), Beijing, China
| | - Jia-Kai He
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences (CACMS), Beijing, China
| | - Guo-Bing Chen
- Department of Microbiology and Immunology, School of Medicine; Institute of Geriatric Immunology, School of Medicine, Jinan University, Guangzhou, China
| | - Pei-Jing Rong
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences (CACMS), Beijing, China
| |
Collapse
|
7
|
Matsumoto H, Tagai K, Endo H, Matsuoka K, Takado Y, Kokubo N, Shimada H, Goto T, Goto TK, Higuchi M. Association of Tooth Loss with Alzheimer's Disease Tau Pathologies Assessed by Positron Emission Tomography. J Alzheimers Dis 2023; 96:1253-1265. [PMID: 37980663 PMCID: PMC10741329 DOI: 10.3233/jad-230581] [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] [Accepted: 09/24/2023] [Indexed: 11/21/2023]
Abstract
BACKGROUND Deterioration of the oral environment is one of the risk factors for dementia. A previous study of an Alzheimer's disease (AD) model mouse suggests that tooth loss induces denervation of the mesencephalic trigeminal nucleus and neuroinflammation, possibly leading to accelerated tau dissemination from the nearby locus coeruleus (LC). OBJECTIVE To elucidate the relevance of oral conditions and amyloid-β (Aβ) and tau pathologies in human participants. METHODS We examined the number of remaining teeth and the biofilm-gingival interface index in 24 AD-spectrum patients and 19 age-matched healthy controls (HCs). They also underwent positron emission tomography (PET) imaging of Aβ and tau with specific radiotracers, 11C-PiB and 18F-PM-PBB3, respectively. All AD-spectrum patients were Aβ-positive, and all HCs were Aβ-negative. We analyzed the correlation between the oral parameters and radiotracer retention. RESULTS No differences were found in oral conditions between the AD and HC groups. 11C-PiB retentions did not correlate with the oral indices in either group. In AD-spectrum patients, brain-wide, voxel-based image analysis highlighted several regions, including the LC and associated brainstem substructures, as areas where 18F-PM-PBB3 retentions negatively correlated with the remaining teeth and revealed the correlation of tau deposits in the LC (r = -0.479, p = 0.018) primarily with the hippocampal and neighboring areas. The tau deposition in none of the brain regions was associated with the periodontal status. CONCLUSIONS Our findings with previous preclinical evidence imply that tooth loss may enhance AD tau pathogenesis, promoting tau spreading from LC to the hippocampal formation.
Collapse
Affiliation(s)
- Hideki Matsumoto
- Department of Oral and Maxillofacial Radiology, Tokyo Dental College, Tokyo, Japan
- Department of Functional Brain Imaging Research, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - Kenji Tagai
- Department of Functional Brain Imaging Research, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba, Japan
- Department of Psychiatry, The Jikei University of Medicine, Tokyo, Japan
| | - Hironobu Endo
- Department of Functional Brain Imaging Research, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - Kiwamu Matsuoka
- Department of Functional Brain Imaging Research, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - Yuhei Takado
- Department of Functional Brain Imaging Research, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - Naomi Kokubo
- Department of Functional Brain Imaging Research, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - Hitoshi Shimada
- Department of Functional Brain Imaging Research, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba, Japan
- Department of Functional Neurology & Neurosurgery, Center for Integrated Human Brain Science, Brain Research Institute, Niigata University, Niigata, Japan
| | - Tetsuya Goto
- Department of Oral Anatomy and Cell Biology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Tazuko K. Goto
- Department of Oral and Maxillofacial Radiology, Tokyo Dental College, Tokyo, Japan
- Department of Functional Brain Imaging Research, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba, Japan
- Tokyo Dental College Research Branding Project, Tokyo Dental College, Tokyo, Japan
- Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| | - Makoto Higuchi
- Department of Functional Brain Imaging Research, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba, Japan
| |
Collapse
|
8
|
The Mechanistic Pathways of Periodontal Pathogens Entering the Brain: The Potential Role of Treponema denticola in Tracing Alzheimer’s Disease Pathology. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19159386. [PMID: 35954742 PMCID: PMC9368682 DOI: 10.3390/ijerph19159386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/26/2022] [Accepted: 07/27/2022] [Indexed: 11/20/2022]
Abstract
Alzheimer’s Disease (AD) is a complex neurodegenerative disease and remains the most common form of dementia. The pathological features include amyloid (Aβ) accumulation, neurofibrillary tangles (NFTs), neural and synaptic loss, microglial cell activation, and an increased blood–brain barrier permeability. One longstanding hypothesis suggests that a microbial etiology is key to AD initiation. Among the various periodontal microorganisms, Porphyromonas gingivalis has been considered the keystone agent to potentially correlate with AD, due to its influence on systemic inflammation. P. gingivalis together with Treponema denticola and Tannerella forsythia belong to the red complex consortium of bacteria advocated to sustain periodontitis within a local dysbiosis and a host response alteration. Since the implication of P. gingivalis in the pathogenesis of AD, evidence has emerged of T. denticola clusters in some AD brain tissue sections. This narrative review explored the potential mode of spirochetes entry into the AD brain for tracing pathology. Spirochetes are slow-growing bacteria, which can hide within ganglia for many years. It is this feature in combination with the ability of these bacteria to evade the hosts’ immune responses that may account for a long lag phase between infection and plausible AD disease symptoms. As the locus coeruleus has direct connection between the trigeminal nuclei to periodontal free nerve endings and proprioceptors with the central nervous system, it is plausible that they could initiate AD pathology from this anatomical region.
Collapse
|
9
|
Toyoda H, Won J, Kim W, Kim H, Davy O, Saito M, Kim D, Tanaka T, Kang Y, Oh SB. The Nature of Noradrenergic Volume Transmission From Locus Coeruleus to Brainstem Mesencephalic Trigeminal Sensory Neurons. Front Cell Neurosci 2022; 16:841239. [PMID: 35558874 PMCID: PMC9087804 DOI: 10.3389/fncel.2022.841239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 03/24/2022] [Indexed: 11/13/2022] Open
Abstract
Noradrenergic neurons in the locus coeruleus (LC) release noradrenaline (NA) that acts via volume transmission to activate extrasynaptic G-protein coupled receptors (GPCRs) in target cells throughout the brain. As the closest projection, the dorsal LC laterally adjoins the mesencephalic trigeminal nucleus (MTN), in which proprioceptive primary sensory neurons innervating muscle spindles of jaw-closing muscles are exceptionally located. MTN neurons express α2-adrenergic receptors (α2-ARs) and display hyperpolarization-activated cyclic nucleotide-gated (HCN) currents (Ihs), which is downregulated by α2-AR activation. To quantify the activity-dependent outcome of volume transmission of NA from LC to MTN, we investigated how direct LC activation inhibits Ih in MTN neurons by performing dual whole-cell recordings from LC and MTN neurons. Repetition of 20 Hz spike-train evoked with 1-s current-pulse in LC neurons every 30 s resulted in a gradual decrease in Ih evoked every 30 s, revealing a Hill-type relationship between the number of spike-trains in LC neurons and the degree of Ih inhibition in MTN neurons. On the other hand, when microstimulation was applied in LC every 30 s, an LC neuron repeatedly displayed a transient higher-frequency firing followed by a tonic firing at 5–10 Hz for 30 s. This subsequently caused a similar Hill-type inhibition of Ih in the simultaneously recorded MTN neuron, but with a smaller Hill coefficient, suggesting a lower signal transduction efficacy. In contrast, 20 Hz activity induced by a 1-s pulse applied every 5–10 s caused only a transient facilitation of Ih inhibition followed by a forced termination of Ih inhibition. Thus, the three modes of LC activities modulated the volume transmission to activate α2-adrenergic GPCR to differentially inhibit Ih in MTN neurons.
Collapse
Affiliation(s)
- Hiroki Toyoda
- Department of Neuroscience and Oral Physiology, Graduate School of Dentistry, Osaka University, Suita, Japan
| | - Jonghwa Won
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, South Korea
- Department of Neurobiology and Physiology, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, South Korea
| | - Wheedong Kim
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, South Korea
| | - Hayun Kim
- Interdisciplinary Program for Brain Science, College of Natural Sciences, Seoul National University, Seoul, South Korea
| | - Oscar Davy
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Mitsuru Saito
- Department of Oral Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Doyun Kim
- Department of Neurobiology and Physiology, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, South Korea
| | - Takuma Tanaka
- Graduate School of Data Science, Shiga University, Hikone, Japan
| | - Youngnam Kang
- Department of Neuroscience and Oral Physiology, Graduate School of Dentistry, Osaka University, Suita, Japan
- Department of Neurobiology and Physiology, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, South Korea
- Department of Behavioral Sciences, Graduate School of Human Sciences, Osaka University, Suita, Japan
| | - Seog Bae Oh
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, South Korea
- Department of Neurobiology and Physiology, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, South Korea
- Interdisciplinary Program for Brain Science, College of Natural Sciences, Seoul National University, Seoul, South Korea
| |
Collapse
|
10
|
Goto T, Kuramoto E, Dhar A, Wang RPH, Seki H, Iwai H, Yamanaka A, Matsumoto SE, Hara H, Michikawa M, Ohyagi Y, Leung WK, Chang RCC. Neurodegeneration of Trigeminal Mesencephalic Neurons by the Tooth Loss Triggers the Progression of Alzheimer's Disease in 3×Tg-AD Model Mice. J Alzheimers Dis 2021; 76:1443-1459. [PMID: 32651317 PMCID: PMC7505011 DOI: 10.3233/jad-200257] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND The mesencephalic trigeminal nucleus (Vmes) is not only anatomically adjacent to the locus coeruleus (LC) but is also tightly associated with the function of the LC. The LC can be the first area in which Alzheimer's disease (AD) develops, although it is unclear how LC neuronal loss occurs. OBJECTIVE We investigated whether neuronal death in the Vmes can be spread to adjacent LC in female triple transgenic (3×Tg)-AD mice, how amyloid-β (Aβ) is involved in LC neuronal loss, and how this neurodegeneration affects cognitive function. METHODS The molars of 3×Tg-AD mice were extracted, and the mice were reared for one week to 4 months. Immunohistochemical analysis, and spatial learning/memory assessment using the Barnes maze were carried out. RESULTS In 4-month-old 3×Tg-AD mice, aggregated cytotoxic Aβ42 was found in granules in Vmes neurons. Neuronal death in the Vmes occurred after tooth extraction, resulting in the release of cytotoxic Aβ42 and an increase in CD86 immunoreactive microglia. Released Aβ42 damaged the LC, in turn inducing a significant reduction in hippocampal neurons in the CA1 and CA3 regions receiving projections from the LC. Based on spatial learning/memory assessment, after the tooth extraction in the 4-month-old 3×Tg-AD mice, increased latency was observed in 5-month-old 3×Tg-AD mice 1 month after tooth extraction, which is similar increase of latency observed in control 8-month-old 3×Tg-AD mice. Measures of cognitive deficits suggested an earlier shift to dementia-like behavior after tooth extraction. CONCLUSION These findings suggest that tooth extraction in the predementia stage can trigger the spread of neurodegeneration from the Vmes, LC, and hippocampus and accelerate the onset of dementia.
Collapse
Affiliation(s)
- Tetsuya Goto
- Department of Oral Anatomy and Cell Biology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Eriko Kuramoto
- Department of Oral Anatomy and Cell Biology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Ashis Dhar
- Department of Oral Anatomy and Cell Biology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Rachel Pei-Hsuan Wang
- Laboratory of Neurodegenerative Diseases, chool of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR
| | - Haruka Seki
- Department of Oral Anatomy and Cell Biology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Haruki Iwai
- Department of Oral Anatomy and Cell Biology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Atsushi Yamanaka
- Department of Oral Anatomy and Cell Biology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Shin-Ei Matsumoto
- Department of Immunology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Hiromitsu Hara
- Department of Immunology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Makoto Michikawa
- Department of Biochemistry, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Yasumasa Ohyagi
- Department of Neurology and Geriatric Medicine, Ehime University Graduate School of Medicine, Ehime, Japan
| | - Wai Keung Leung
- Periodontology and Implant Dentistry, Faculty of Dentistry, The University of Hong Kong, Pokfulam, Hong Kong SAR
| | - Raymond Chuen-Chung Chang
- Laboratory of Neurodegenerative Diseases, chool of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR.,State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR
| |
Collapse
|
11
|
Electroacupuncture on Trigeminal Nerve-Innervated Acupoints Ameliorates Poststroke Cognitive Impairment in Rats with Middle Cerebral Artery Occlusion: Involvement of Neuroprotection and Synaptic Plasticity. Neural Plast 2020; 2020:8818328. [PMID: 32963517 PMCID: PMC7492933 DOI: 10.1155/2020/8818328] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 08/13/2020] [Accepted: 08/18/2020] [Indexed: 12/27/2022] Open
Abstract
Poststroke cognitive impairment (PSCI) is a severe sequela of stroke. There are no effective therapeutic options for it. In this study, we evaluated whether electroacupuncture (EA) on the trigeminal nerve-innervated acupoints could alleviate PSCI and identified the mechanisms in an animal model. The male Sprague-Dawley rat middle cerebral artery occlusion (MCAO) model was used in our study. EA was conducted on the two scalp acupoints, EX-HN3 (Yintang) and GV20 (Baihui), innervated by the trigeminal nerve, for 14 sessions, daily. Morris water maze and novel object recognition were used to evaluate the animal's cognitive performance. Neuroprotection and synaptic plasticity biomarkers were analyzed in brain tissues. Ischemia-reperfusion (I/R) injury significantly impaired spatial and cognition memory, while EA obviously reversed cognitive deterioration to the control level in the two cognitive paradigms. Moreover, EA reversed the I/R injury-induced decrease of brain-derived neurotrophic factor, tyrosine kinase B, N-methyl-D-aspartic acid receptor 1, α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor, γ-aminobutyric acid type A receptors, Ca2+/calmodulin-dependent protein kinase II, neuronal nuclei, and postsynaptic density protein 95 expression in the prefrontal cortex and hippocampus. These results suggest that EA on the trigeminal nerve-innervated acupoints is an effective therapy for PSCI, in association with mediating neuroprotection and synaptic plasticity in related brain regions in the MCAO rat model.
Collapse
|
12
|
Zhang ZJ, Man SC, Yam LL, Yiu CY, Leung RCY, Qin ZS, Chan KWS, Lee VHF, Kwong A, Yeung WF, So WKW, Ho LM, Dong YY. Electroacupuncture trigeminal nerve stimulation plus body acupuncture for chemotherapy-induced cognitive impairment in breast cancer patients: An assessor-participant blinded, randomized controlled trial. Brain Behav Immun 2020; 88:88-96. [PMID: 32305573 DOI: 10.1016/j.bbi.2020.04.035] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 04/08/2020] [Accepted: 04/13/2020] [Indexed: 02/07/2023] Open
Abstract
Chemotherapy causes various side effects, including cognitive impairment, known as 'chemobrain'. In this study, we determined whether a novel acupuncture mode called electroacupuncture trigeminal nerve stimulation plus body acupuncture (EA/TNS + BA) could produce better outcomes than minimum acupuncture stimulation (MAS) as controls in treating chemobrain and other symptoms in breast cancer patients. In this assessor- and participant-blinded, randomized controlled trial, 93 breast cancer patients under or post chemotherapy were randomly assigned to EA/TNS + BA (n = 46) and MAS (n = 47) for 2 sessions per week over 8 weeks. The Montreal Cognitive Assessment (MoCA) served as the primary outcome. Digit span test was the secondary outcomes for attentional function and working memory. The quality of life and multiple functional assessments were also evaluated. EA/TNS + BA treated group had much better performance than MAS-treated group on reverse digit span test at Week 2 and Week 8, with medium effect sizes of 0.53 and 0.48, respectively, although no significant differences were observed in MoCA score and prevalence of chemobrain between the two groups. EA/TNS + BA also markedly reduced incidences of diarrhoea, poor appetite, headache, anxiety, and irritation, and improved social/family and emotional wellbeing compared to MAS. These results suggest that EA/TNS + BA may have particular benefits in reducing chemotherapy-induced working memory impairment and the incidence of certain digestive, neurological, and distress-related symptoms. It could serve as an effective intervention for breast cancer patients under and post chemotherapy (trial registration: https://www.clinicaltrials.gov: NCT02457039).
Collapse
Affiliation(s)
- Zhang-Jin Zhang
- Department of Chinese Medicine, The University of Hong Kong Shenzhen Hospital (HKU-SZH), Shenzhen, Guangdong 518053, China; School of Chinese Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
| | - Sui-Cheung Man
- School of Chinese Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Lo-Lo Yam
- School of Chinese Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Chui Ying Yiu
- School of Chinese Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Roland Ching-Yu Leung
- Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Zong-Shi Qin
- School of Chinese Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Kit-Wa Sherry Chan
- Department of Psychiatry, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Victor Ho Fun Lee
- Department of Clinical Oncology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Ava Kwong
- Department of Surgery, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Wing-Fai Yeung
- School of Nursing, The Hong Kong Polytechnic University, Hong Kong, China
| | - Winnie K W So
- The Nethersole School of Nursing, Faculty of Medicine, The Chinese University of Hong Kong, New Territory, Hong Kong
| | - Lai Ming Ho
- School of Public Health, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Ying-Ying Dong
- Department of Psychosomatic Disorders, The Seventh People Hospital of Shaoxing, Shaoxing, Zhejiang 312000, China.
| |
Collapse
|
13
|
Zhang ZJ, Zhao H, Jin GX, Man SC, Wang YS, Wang Y, Wang HR, Li MH, Yam LL, Qin ZS, Yu KKT, Wu J, Ng FLB, Ziea TCE, Rong PJ. Assessor- and participant-blinded, randomized controlled trial of dense cranial electroacupuncture stimulation plus body acupuncture for neuropsychiatric sequelae of stroke. Psychiatry Clin Neurosci 2020; 74:183-190. [PMID: 31747095 DOI: 10.1111/pcn.12959] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 10/19/2019] [Accepted: 11/13/2019] [Indexed: 11/30/2022]
Abstract
AIM Acupuncture has benefits in the rehabilitation of neuropsychiatric sequelae of stroke. This study was aimed to evaluate the effectiveness of dense cranial electroacupuncture stimulation plus body acupuncture (DCEAS+BA) in treating poststroke depression (PSD), functional disability, and cognitive deterioration. METHODS In this assessor- and participant-blinded, randomized controlled trial, 91 stroke patients who initially had PSD were randomly assigned to either DCEAS+BA (n = 45) or minimum acupuncture stimulation as controls (n = 46) for three sessions per week over 8 consecutive weeks. The primary outcome was baseline-to-end-point change in score of the 17-item Hamilton Depression Rating Scale. Secondary outcomes included the Montgomery-Åsberg Depression Rating Scale for depressive symptoms, the Barthel Index for functional disability, and the Montreal Cognitive Assessment for cognitive function. RESULTS DCEAS+BA-treated patients showed strikingly greater end-point reduction than MAS-treated patients in scores of the three symptom domains. The clinical response rate, defined as an at least 50% baseline-to-end-point reduction in 17-item Hamilton Depression Rating Scale score, was markedly higher in the DCEAS+BA-treated group than that of controls (40.0% vs 17.4%, P = 0.031). Incidence of adverse events was not different in the two groups. Subgroup analysis revealed that DCEAS+BA with electrical stimulation on forehead acupoints was more apparent in reducing Barthel-Index-measured disability than that without electrical stimulation. CONCLUSION DCEAS+BA, particularly with electrical stimulation on forehead acupoints, reduces PSD, functional disability, and cognitive deterioration of stroke patients. It can serve as an effective rehabilitation therapy for neuropsychiatric sequelae of stroke.
Collapse
Affiliation(s)
- Zhang-Jin Zhang
- School of Chinese Medicine, University of Hong Kong, Hong Kong, China
| | - Hong Zhao
- Department of Acupuncture and Moxibustion, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, National Clinical Research Center of Traditional Chinese Medicine, Tianjin, China
| | - Gui-Xing Jin
- Department of Psychiatry, First Hospital of Hebei Medical University, Shijiazhuang, China
| | - Sui-Cheung Man
- School of Chinese Medicine, University of Hong Kong, Hong Kong, China
| | - Yi-Si Wang
- Department of Acupuncture and Moxibustion, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, National Clinical Research Center of Traditional Chinese Medicine, Tianjin, China
| | - Ying Wang
- Department of Acupuncture and Moxibustion, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, National Clinical Research Center of Traditional Chinese Medicine, Tianjin, China
| | - Hai-Rong Wang
- Department of Acupuncture and Moxibustion, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, National Clinical Research Center of Traditional Chinese Medicine, Tianjin, China
| | - Meng-Han Li
- Department of Acupuncture and Moxibustion, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, National Clinical Research Center of Traditional Chinese Medicine, Tianjin, China
| | - Lo-Lo Yam
- School of Chinese Medicine, University of Hong Kong, Hong Kong, China
| | - Zong-Shi Qin
- School of Chinese Medicine, University of Hong Kong, Hong Kong, China
| | - Kim-Kam Teresa Yu
- Department of Rehabilitation, Kowloon Hospital, Kowloon, Hong Kong, China
| | - Jing Wu
- Hong Kong Buddhist Association, The University of Hong Kong Clinical Centre for Teaching and Research in Chinese Medicine, Kowloon, Hong Kong
| | | | | | - Pei-Jing Rong
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| |
Collapse
|
14
|
Won J, Lee PR, Oh SB. Alpha 2 adrenoceptor agonist guanabenz directly inhibits hyperpolarization-activated, cyclic nucleotide-modulated (HCN) channels in mesencephalic trigeminal nucleus neurons. Eur J Pharmacol 2019; 854:320-327. [PMID: 31009638 DOI: 10.1016/j.ejphar.2019.04.036] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 04/03/2019] [Accepted: 04/18/2019] [Indexed: 10/27/2022]
Abstract
Alpha 2 (α2-) adrenoceptor agonists, such as clonidine or dexmedetomidine, have been found to inhibit hyperpolarization-activated, cyclic nucleotide-modulated (HCN) channels, not only by reducing intracellular cyclic AMP levels but also by directly blocking HCN channels. In this study, we examined the inhibitory effect of guanabenz, a centrally acting α2-adrenoceptor agonist with high specificity for α2A-subtype, on HCN channels in mesencephalic trigeminal nucleus (MTN) neurons which robustly express HCN channels and have been suggested to coexpress α2A-adrenoceptors. By performing whole-cell patch-clamp recording on MTN neurons in brainstem slices, hyperpolarization-activated inward current (Ih) was examined during guanabenz treatment. Guanabenz inhibited Ih in a dose-dependent manner, which was likely to be ZD7288-sensitive HCN current as it did not affect barium-sensitive inward rectifying potassium current. Guanabenz not only inhibited Ih but also shifted the voltage-dependent activation curve to hyperpolarizing potentials. Interestingly, Ih inhibition by guanabenz was not reversed by α2-adrenoceptor antagonist atipamezole treatment or by intracellular cyclic AMP perfusion, suggesting that the inhibition may not result from α2A-adrenoceptor signalling pathway but from direct inhibition of HCN channels. Coherent to our electrophysiological results, single-cell RT-PCR revealed that most MTN neurons lack α2A-adrenoceptor mRNA. Our study demonstrates that guanabenz can directly inhibit HCN channels in addition to its primary role of activating α2A-adrenoceptors.
Collapse
Affiliation(s)
- Jonghwa Won
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea
| | - Pa Reum Lee
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea
| | - Seog Bae Oh
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea; Dental Research Institute and Department of Neurobiology and Physiology, School of Dentistry, Seoul National University, Republic of Korea.
| |
Collapse
|
15
|
Kawasaki Y, Saito M, Won J, Bae JY, Sato H, Toyoda H, Kuramoto E, Kogo M, Tanaka T, Kaneko T, Oh SB, Bae YC, Kang Y. Inhibition of GluR Current in Microvilli of Sensory Neurons via Na +-Microdomain Coupling Among GluR, HCN Channel, and Na +/K + Pump. Front Cell Neurosci 2018; 12:113. [PMID: 29740287 PMCID: PMC5928758 DOI: 10.3389/fncel.2018.00113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 04/06/2018] [Indexed: 11/13/2022] Open
Abstract
Glutamatergic dendritic EPSPs evoked in cortical pyramidal neurons are depressed by activation of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels expressed in dendritic spines. This depression has been attributed to shunting effects of HCN current (Ih) on input resistance or Ih deactivation. Primary sensory neurons in the rat mesencephalic trigeminal nucleus (MTN) have the somata covered by spine-like microvilli that express HCN channels. In rat MTN neurons, we demonstrated that Ih enhancement apparently diminished the glutamate receptor (GluR) current (IGluR) evoked by puff application of glutamate/AMPA and enhanced a transient outward current following IGluR (OT-IGluR). This suggests that some outward current opposes inward IGluR. The IGluR inhibition displayed a U-shaped voltage-dependence with a minimal inhibition around the resting membrane potential, suggesting that simple shunting effects or deactivation of Ih cannot explain the U-shaped voltage-dependence. Confocal imaging of Na+ revealed that GluR activation caused an accumulation of Na+ in the microvilli, which can cause a negative shift of the reversal potential for Ih (Eh). Taken together, it was suggested that IGluR evoked in MTN neurons is opposed by a transient decrease or increase in standing inward or outward Ih, respectively, both of which can be caused by negative shifts of Eh, as consistent with the U-shaped voltage-dependence of the IGluR inhibition and the OT-IGluR generation. An electron-microscopic immunohistochemical study revealed the colocalization of HCN channels and glutamatergic synapses in microvilli of MTN neurons, which would provide a morphological basis for the functional interaction between HCN and GluR channels. Mathematical modeling eliminated the possibilities of the involvements of Ih deactivation and/or shunting effect and supported the negative shift of Eh which causes the U-shaped voltage-dependent inhibition of IGluR.
Collapse
Affiliation(s)
- Yasuhiro Kawasaki
- Department of Neuroscience and Oral Physiology, Graduate School of Dentistry, Osaka University, Osaka, Japan
| | - Mitsuru Saito
- Department of Neuroscience and Oral Physiology, Graduate School of Dentistry, Osaka University, Osaka, Japan
| | - Jonghwa Won
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Dental Research Institute and Department of Neurobiology and Physiology, School of Dentistry, Seoul National University, Seoul, South Korea
| | - Jin Young Bae
- Department of Oral Anatomy, School of Dentistry, Kyungpook National University, Daegu, South Korea
| | - Hajime Sato
- Department of Neuroscience and Oral Physiology, Graduate School of Dentistry, Osaka University, Osaka, Japan
| | - Hiroki Toyoda
- Department of Neuroscience and Oral Physiology, Graduate School of Dentistry, Osaka University, Osaka, Japan
| | - Eriko Kuramoto
- Department of Morphological Brain Science, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Mikihiko Kogo
- Department of Neuroscience and Oral Physiology, Graduate School of Dentistry, Osaka University, Osaka, Japan
| | - Takuma Tanaka
- Department of Computational Intelligence and Systems Science, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Yokohama, Japan
| | - Takeshi Kaneko
- Department of Morphological Brain Science, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Seog Bae Oh
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Dental Research Institute and Department of Neurobiology and Physiology, School of Dentistry, Seoul National University, Seoul, South Korea
| | - Yong Chul Bae
- Department of Oral Anatomy, School of Dentistry, Kyungpook National University, Daegu, South Korea
| | - Youngnam Kang
- Department of Neuroscience and Oral Physiology, Graduate School of Dentistry, Osaka University, Osaka, Japan
| |
Collapse
|
16
|
Modulation of brainstem activity and connectivity by respiratory-gated auricular vagal afferent nerve stimulation in migraine patients. Pain 2018; 158:1461-1472. [PMID: 28541256 DOI: 10.1097/j.pain.0000000000000930] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Migraine pathophysiology includes altered brainstem excitability, and recent neuromodulatory approaches aimed at controlling migraine episodes have targeted key brainstem relay and modulatory nuclei. In this study, we evaluated the impact of respiratory-gated auricular vagal afferent nerve stimulation (RAVANS), a novel neuromodulatory intervention based on an existing transcutaneous vagus nerve stimulation approach, in the modulation of brainstem activity and connectivity in migraine patients. We applied 3T-functional magnetic resonance imaging with improved in-plane spatial resolution (2.62 × 2.62 mm) in episodic migraine (interictal) and age- and sex-matched healthy controls to evaluate brain response to RAVANS (gated to either inhalation or exhalation) and sham stimulation. We further investigated RAVANS modulation of tactile trigeminal sensory afference response in the brainstem using air-puff stimulation directed to the forehead during functional magnetic resonance imaging. Compared with sham and inhalatory-gated RAVANS (iRAVANS), exhalatory-gated RAVANS (eRAVANS) activated an ipsilateral pontomedullary region consistent with nucleus tractus solitarii (NTS). During eRAVANS, NTS connectivity was increased to anterior insula and anterior midcingulate cortex, compared with both sham and iRAVANS, in migraine patients. Increased connectivity was inversely correlated with relative time to the next migraine attack, suggesting clinical relevance to this change in connectivity. Poststimulation effects were also noted immediately after eRAVANS, as we found increased activation in putative pontine serotonergic (ie, nucleus raphe centralis) and noradrenergic (ie, locus coeruleus) nuclei in response to trigeminal sensory afference. Regulation of activity and connectivity of brainstem and cortical regions involved in serotonergic and noradrenergic regulation and pain modulation may constitute an underlying mechanism supporting beneficial clinical outcomes for eRAVANS applied for episodic migraine.
Collapse
|
17
|
Bae JY, Lee JS, Ko SJ, Cho YS, Rah JC, Cho HJ, Park MJ, Bae YC. Extrasynaptic homomeric glycine receptors in neurons of the rat trigeminal mesencephalic nucleus. Brain Struct Funct 2018; 223:2259-2268. [PMID: 29460053 DOI: 10.1007/s00429-018-1607-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 11/29/2017] [Indexed: 12/19/2022]
Abstract
The neurons in the trigeminal mesencephalic nucleus (Vmes) innervate jaw-closing muscle spindles and periodontal ligaments, and play a crucial role in the regulation of jaw movements. Recently, it was shown that many boutons that form synapses on them are immunopositive for glycine (Gly+), suggesting that these neurons receive glycinergic input. Information about the glycine receptors that mediate this input is needed to help understand the role of glycine in controlling Vmes neuron excitability. For this, we investigated the expression of glycine receptor subunit alpha 3 (GlyRα3) and gephyrin in neurons in Vmes and the trigeminal motor nucleus (Vmo), and the Gly+ boutons that contact them by light- and electron-microscopic immunocytochemistry and quantitative ultrastructural analysis. The somata of the Vmes neurons were immunostained for GlyRα3, but not gephyrin, indicating expression of homomeric GlyR. The immunostaining for GlyRα3 was localized away from the synapses in the Vmes neuron somata, in contrast to the Vmo neurons, where the staining for GlyRα3 and gephyrin were localized at the subsynaptic zones in somata and dendrites. Additionally, the ultrastructural determinants of synaptic strength, bouton volume, mitochondrial volume, and active zone area, were significantly smaller in Gly+ boutons on the Vmes neurons than in those on the Vmo neurons. These findings support the notion that the Vmes neurons receive glycinergic input via putative extrasynaptic homomeric glycine receptors, likely mediating a slow, tonic modulation of the Vmes neuron excitability.
Collapse
Affiliation(s)
- Jin Young Bae
- Department of Anatomy and Neurobiology, School of Medicine and Dentistry, Kyungpook National University, 188-1, 2-Ga, Samdeok-Dong, Jung-Gu, Daegu, 700-412, South Korea
| | - Jae Sik Lee
- Department of Anatomy and Neurobiology, School of Medicine and Dentistry, Kyungpook National University, 188-1, 2-Ga, Samdeok-Dong, Jung-Gu, Daegu, 700-412, South Korea
| | - Sang Jin Ko
- Department of Anatomy and Neurobiology, School of Medicine and Dentistry, Kyungpook National University, 188-1, 2-Ga, Samdeok-Dong, Jung-Gu, Daegu, 700-412, South Korea
| | - Yi Sul Cho
- Department of Anatomy and Neurobiology, School of Medicine and Dentistry, Kyungpook National University, 188-1, 2-Ga, Samdeok-Dong, Jung-Gu, Daegu, 700-412, South Korea
| | - Jong-Cheol Rah
- Korea Brian Research Institute, 61 Cheomdan-ro, Dong-gu, Daegu, 701-300, South Korea
| | - Hee Jung Cho
- Department of Anatomy and Neurobiology, School of Medicine and Dentistry, Kyungpook National University, 188-1, 2-Ga, Samdeok-Dong, Jung-Gu, Daegu, 700-412, South Korea
| | - Mae Ja Park
- Department of Anatomy and Neurobiology, School of Medicine and Dentistry, Kyungpook National University, 188-1, 2-Ga, Samdeok-Dong, Jung-Gu, Daegu, 700-412, South Korea
| | - Yong Chul Bae
- Department of Anatomy and Neurobiology, School of Medicine and Dentistry, Kyungpook National University, 188-1, 2-Ga, Samdeok-Dong, Jung-Gu, Daegu, 700-412, South Korea.
| |
Collapse
|
18
|
Ohara H, Tachibana Y, Fujio T, Takeda-Ikeda R, Sato F, Oka A, Kato T, Ikenoue E, Yamashiro T, Yoshida A. Direct projection from the lateral habenula to the trigeminal mesencephalic nucleus in rats. Brain Res 2015; 1630:183-97. [PMID: 26592775 DOI: 10.1016/j.brainres.2015.11.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 09/29/2015] [Accepted: 11/08/2015] [Indexed: 12/30/2022]
Abstract
Trigeminal mesencephalic nucleus (Vmes) neurons are primary afferents conveying deep sensation from the masticatory muscle spindles or the periodontal mechanoreceptors, and are crucial for controlling jaw movements. Their cell bodies exist in the brain and receive descending commands from a variety of cortical and subcortical structures involved in limbic (emotional) systems. However, it remains unclear how the lateral habenula (LHb), a center of negative emotions (e.g., pain, stress and anxiety), can influence the control of jaw movements. To address this issue, we examined whether and how the LHb directly projects to the Vmes by means of neuronal tract tracing techniques in rats. After injections of a retrograde tracer Fluorogold in the rostral and caudal Vmes, a number of neurons were labeled in the lateral division of LHb (LHbl) bilaterally, whereas a few neurons were labeled in the medial division of LHb (LHbm) bilaterally. After injections of an anterograde tracer, biotinylated dextranamine (BDA) in the LHbl, a small number of labeled axons were distributed bilaterally in the rostral and caudal levels of Vmes, where some labeled axonal boutons contacted the cell body of rostral and caudal levels of Vmes neurons bilaterally. After the BDA injection into the LHbm, however, no axons were labeled bilaterally in the rostral and caudal levels of Vmes. Therefore, the present study for the first time demonstrated the direct projection from the LHbl to the Vmes and the detailed projection patterns, suggesting that jaw movements are modulated by negative emotions that are signaled by LHbl neurons.
Collapse
Affiliation(s)
- Haruka Ohara
- Department of Oral Anatomy and Neurobiology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan; Department of Orthodontics and Dentofacial Orthopedics, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan
| | - Yoshihisa Tachibana
- Department of Oral Anatomy and Neurobiology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan
| | - Takashi Fujio
- Department of Oral Anatomy and Neurobiology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan
| | - Rieko Takeda-Ikeda
- Department of Oral Anatomy and Neurobiology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan; Department of Orthodontics and Dentofacial Orthopedics, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan
| | - Fumihiko Sato
- Department of Oral Anatomy and Neurobiology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan
| | - Ayaka Oka
- Department of Oral Anatomy and Neurobiology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan; Department of Orthodontics and Dentofacial Orthopedics, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan
| | - Takafumi Kato
- Department of Oral Anatomy and Neurobiology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan
| | - Etsuko Ikenoue
- Department of Oral Anatomy and Neurobiology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan
| | - Takashi Yamashiro
- Department of Orthodontics and Dentofacial Orthopedics, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan
| | - Atsushi Yoshida
- Department of Oral Anatomy and Neurobiology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan.
| |
Collapse
|
19
|
Paik SK, Kwak MK, Bae JY, Yi HW, Yoshida A, Ahn DK, Bae YC. γ-Aminobutyric acid-, glycine-, and glutamate-immunopositive boutons on mesencephalic trigeminal neurons that innervate jaw-closing muscle spindles in the rat: Ultrastructure and development. J Comp Neurol 2012; 520:3414-27. [DOI: 10.1002/cne.23110] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
20
|
Neural acupuncture unit: a new concept for interpreting effects and mechanisms of acupuncture. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2012; 2012:429412. [PMID: 22474503 PMCID: PMC3310280 DOI: 10.1155/2012/429412] [Citation(s) in RCA: 136] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2011] [Revised: 11/30/2011] [Accepted: 12/01/2011] [Indexed: 12/12/2022]
Abstract
When an acupuncture needle is inserted into a designated point on the body and
mechanical or electrical stimulation is delivered, various neural and neuroactive
components are activated. The collection of the activated neural and neuroactive
components distributed in the skin, muscle, and connective tissues surrounding the
inserted needle is defined as a neural acupuncture unit (NAU). The traditionally defined
acupoints represent an anatomical landmark system that indicates local sites where NAUs
may contain relatively dense and concentrated neural and neuroactive components, upon
which acupuncture stimulation would elicit a more efficient therapeutic response. The
NAU-based local mechanisms of biochemical and biophysical reactions play an important
role in acupuncture-induced analgesia. Different properties of NAUs are associated with
different components of needling sensation. There exist several central pathways to
convey NAU-induced acupuncture signals, Electroacupuncture (EA) frequency-specific
neurochemical effects are related to different peripheral and central pathways transmitting
afferent signals from different frequency of NAU stimulation. More widespread and intense
neuroimaging responses of brain regions to acupuncture may be a consequence of more
efficient NAU stimulation modes. The introduction of the conception of NAU provides a
new theoretical approach to interpreting effects and mechanisms of acupuncture in
modern biomedical knowledge framework.
Collapse
|
21
|
Morquette P, Lavoie R, Fhima MD, Lamoureux X, Verdier D, Kolta A. Generation of the masticatory central pattern and its modulation by sensory feedback. Prog Neurobiol 2012; 96:340-55. [PMID: 22342735 DOI: 10.1016/j.pneurobio.2012.01.011] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Revised: 01/16/2012] [Accepted: 01/24/2012] [Indexed: 11/25/2022]
Abstract
The basic pattern of rhythmic jaw movements produced during mastication is generated by a neuronal network located in the brainstem and referred to as the masticatory central pattern generator (CPG). This network composed of neurons mostly associated to the trigeminal system is found between the rostral borders of the trigeminal motor nucleus and facial nucleus. This review summarizes current knowledge on the anatomical organization, the development, the connectivity and the cellular properties of these trigeminal circuits in relation to mastication. Emphasis is put on a population of rhythmogenic neurons in the dorsal part of the trigeminal sensory nucleus. These neurons have intrinsic bursting capabilities, supported by a persistent Na(+) current (I(NaP)), which are enhanced when the extracellular concentration of Ca(2+) diminishes. Presented evidence suggest that the Ca(2+) dependency of this current combined with its voltage-dependency could provide a mechanism for cortical and sensory afferent inputs to the nucleus to interact with the rhythmogenic properties of its neurons to adjust and adapt the rhythmic output. Astrocytes are postulated to contribute to this process by modulating the extracellular Ca(2+) concentration and a model is proposed to explain how functional microdomains defined by the boundaries of astrocytic syncitia may form under the influence of incoming inputs.
Collapse
Affiliation(s)
- Philippe Morquette
- Groupe de Recherche sur le Système Nerveux Central du FRSQ, Université de Montréal and Faculté de médecine dentaire, Université de Montréal, Canada
| | | | | | | | | | | |
Collapse
|
22
|
Zhang ZJ, Ng R, Man SC, Li TYJ, Wong W, Tan QR, Wong HK, Chung KF, Wong MT, Tsang WKA, Yip KC, Ziea E, Wong VT. Dense cranial electroacupuncture stimulation for major depressive disorder--a single-blind, randomized, controlled study. PLoS One 2012; 7:e29651. [PMID: 22238631 PMCID: PMC3253099 DOI: 10.1371/journal.pone.0029651] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Accepted: 11/30/2011] [Indexed: 12/04/2022] Open
Abstract
Background Previous studies suggest that electroacupuncture possesses therapeutic benefits for depressive disorders. The purpose of this study was to determine whether dense cranial electroacupuncture stimulation (DCEAS) could enhance the antidepressant efficacy in the early phase of selective serotonin reuptake inhibitor (SSRI) treatment of major depressive disorder (MDD). Methods In this single-blind, randomized, controlled study, patients with MDD were randomly assigned to 9-session DCEAS or noninvasive electroacupuncture (n-EA) control procedure in combination with fluoxetine (FLX) for 3 weeks. Clinical outcomes were measured using the 17-item Hamilton Depression Rating Scale (HAMD-17), Clinical Global Impression-severity (CGI-S), and Self-rating Depression Scale (SDS) as well as the response and remission rates. Results Seventy-three patients were randomly assigned to n-EA (n = 35) and DCEAS (n = 38), of whom 34 in n-EA and 36 in DCEAS group were analyzed. DCEAS-treated patients displayed a significantly greater reduction from baseline in HAMD-17 scores at Day 3 through Day 21 and in SDS scores at Day 3 and Day 21 compared to patients receiving n-EA. DCEAS intervention also produced a higher rate of clinically significant response compared to n-EA procedure (19.4% (7/36) vs. 8.8% (3/34)). The incidence of adverse events was similar in the two groups. Conclusions DCEAS is a safe and effective intervention that augments the antidepressant efficacy. It can be considered as an additional therapy in the early phase of SSRI treatment of depressed patients. Trial Registration Controlled-Trials.comISRCTN88008690
Collapse
Affiliation(s)
- Zhang-Jin Zhang
- School of Chinese Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Shirasu M, Takahashi T, Yamamoto T, Itoh K, Sato S, Nakamura H. Direct projections from the central amygdaloid nucleus to the mesencephalic trigeminal nucleus in rats. Brain Res 2011; 1400:19-30. [DOI: 10.1016/j.brainres.2011.05.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2010] [Revised: 05/10/2011] [Accepted: 05/12/2011] [Indexed: 12/30/2022]
|