1
|
Katagiri A, Yamada M, Sato H, Toyoda H, Niwa H, Kato T. Long-lasting adverse effects of short-term stress during the suckling-mastication transition period on masticatory function and intraoral sensation in rats. Odontology 2024; 112:906-916. [PMID: 38197987 PMCID: PMC11269417 DOI: 10.1007/s10266-023-00887-w] [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: 08/28/2023] [Accepted: 12/10/2023] [Indexed: 01/11/2024]
Abstract
Early-life stress affects brain development, eventually resulting in adverse behavioral and physical health consequences in adulthood. The present study assessed the hypothesis that short-term early-life stress during infancy before weaning, a period for the maturation of mastication and sleep, poses long-lasting adverse effects on masticatory function and intraoral sensations later in life.Rat pups were exposed to either maternal separation (MS) or intermittent hypoxia (IH-Infancy) for 6 h/day in the light/sleep phase from postnatal day (P)17 to P20 to generate "neglect" and "pediatric obstructive sleep apnea" models, respectively. The remaining rats were exposed to IH during P45-P48 (IH-Adult). Masticatory ability was evaluated based on the rats' ability to chew pellets and bite pasta throughout the growth period (P21-P70). Intraoral chemical and mechanical sensitivities were assessed using two-bottle preference drinking tests, and hind paw pain thresholds were measured in adulthood (after P60).No differences were found in body weight, grip force, and hind paw sensitivity in MS, IH-Infancy, and IH-Adult rats compared with naïve rats. Masticatory ability was lower in MS and IH-Infancy rats from P28 to P70 than in naïve rats. MS and IH-Infancy rats exhibited intraoral hypersensitivity to capsaicin and mechanical stimulations in adulthood. The IH-Adult rats did not display inferior masticatory ability or intraoral hypersensitivity.In conclusion, short-term early-life stress during the suckling-mastication transition period potentially causes a persistent decrease in masticatory ability and intraoral hypersensitivity in adulthood. The period is a "critical window" for the maturation of oral motor and sensory functions.
Collapse
Affiliation(s)
- Ayano Katagiri
- Department of Oral Physiology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita-shi, Osaka, 565-0871, Japan.
| | - Masaharu Yamada
- Department of Oral Physiology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita-shi, Osaka, 565-0871, Japan
- Department of Dental Anesthesiology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita-shi, Osaka, 565-0871, Japan
| | - Hajime Sato
- Division of Pharmacology, Meikai University School of Dentistry, 1-1 Keyakidai, Sakado-shi, Saitama, 350-0283, Japan
| | - Hiroki Toyoda
- Department of Oral Physiology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita-shi, Osaka, 565-0871, Japan
| | - Hitoshi Niwa
- Department of Dental Anesthesiology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita-shi, Osaka, 565-0871, Japan
| | - Takafumi Kato
- Department of Oral Physiology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita-shi, Osaka, 565-0871, Japan.
| |
Collapse
|
2
|
Cho YS, Mah W, Youn DH, Kim YS, Ko HG, Bae JY, Kim YS, Bae YC. Increase of glutamate in satellite glial cells of the trigeminal ganglion in a rat model of craniofacial neuropathic pain. Front Neuroanat 2023; 17:1302373. [PMID: 38164516 PMCID: PMC10758013 DOI: 10.3389/fnana.2023.1302373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 11/27/2023] [Indexed: 01/03/2024] Open
Abstract
Introduction Satellite glial cells (SGCs) that envelop the cell bodies of neurons in sensory ganglia have been shown to both release glutamate, and be activated by glutamate in the context of nociceptive signaling. However, little is known about the subpopulations of SGCs that are activated following nerve injury and whether glutamate mechanisms in the SGCs are involved in the pathologic pain. Methods To address this issue, we used light and electron microscopic immunohistochemistry to examine the change in the glutamate levels in the SGCs and the structural relationship between neighboring neurons in the trigeminal ganglion (TG) in a rat model of craniofacial neuropathic pain, CCI-ION. Results Administration of ionomycin, ATP and Bz-ATP induced an increase of extracellular glutamate concentration in cultured trigeminal SGCs, indicating a release of glutamate from SGCs. The level of glutamate immunostaining in the SGCs that envelop neurons of all sizes in the TG was significantly higher in rats with CCI-ION than in control rats, suggesting that SGCs enveloping nociceptive as well as non-nociceptive mechanosensitive neurons are activated following nerve injury, and that the glutamate release from SGCs increases in pathologic pain state. Close appositions between substance-P (SP)-immunopositive (+) or calcitonin gene-related peptide (CGRP)+, likely nociceptive neurons, between Piezo1+, likely non-nociceptive, mechanosensitive neurons and SP+ or CGRP+ neurons, and between SGCs of neighboring neurons were frequently observed. Discussion These findings suggest that glutamate in the trigeminal SGCs that envelop all types of neurons may play a role in the mechanisms of neuropathic pain, possibly via paracrine signaling.
Collapse
Affiliation(s)
- Yi Sul Cho
- Department of Anatomy, Physiology and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea
| | - Won Mah
- Department of Anatomy, Physiology and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea
| | - Dong Ho Youn
- Department of Anatomy, Physiology and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea
| | - Yu Shin Kim
- Department of Oral & Maxillofacial Surgery, School of Dentistry, Programs in Integrated Biomedical Sciences, Translational Sciences, Biomedical Engineering, Radiological Sciences, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| | - Hyoung-Gon Ko
- Department of Anatomy, Physiology and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea
| | - Jin Young Bae
- Department of Anatomy, Physiology and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea
| | - Yun Sook Kim
- Department of Anatomy, Physiology and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea
| | - Yong Chul Bae
- Department of Anatomy, Physiology and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea
| |
Collapse
|
3
|
Kim S, Oh H, Choi SH, Yoo YE, Noh YW, Cho Y, Im GH, Lee C, Oh Y, Yang E, Kim G, Chung WS, Kim H, Kang H, Bae Y, Kim SG, Kim E. Postnatal age-differential ASD-like transcriptomic, synaptic, and behavioral deficits in Myt1l-mutant mice. Cell Rep 2022; 40:111398. [PMID: 36130507 DOI: 10.1016/j.celrep.2022.111398] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 06/28/2022] [Accepted: 08/31/2022] [Indexed: 12/29/2022] Open
Abstract
Myelin transcription factor 1 like (Myt1l), a zinc-finger transcription factor, promotes neuronal differentiation and is implicated in autism spectrum disorder (ASD) and intellectual disability. However, it remains unclear whether Myt1l promotes neuronal differentiation in vivo and its deficiency in mice leads to disease-related phenotypes. Here, we report that Myt1l-heterozygous mutant (Myt1l-HT) mice display postnatal age-differential ASD-related phenotypes: newborn Myt1l-HT mice, with strong Myt1l expression, show ASD-like transcriptomic changes involving decreased synaptic gene expression and prefrontal excitatory synaptic transmission and altered righting reflex. Juvenile Myt1l-HT mice, with markedly decreased Myt1l expression, display reverse ASD-like transcriptomes, increased prefrontal excitatory transmission, and largely normal behaviors. Adult Myt1l-HT mice show ASD-like transcriptomes involving astrocytic and microglial gene upregulation, increased prefrontal inhibitory transmission, and behavioral deficits. Therefore, Myt1l haploinsufficiency leads to ASD-related phenotypes in newborn mice, which are temporarily normalized in juveniles but re-appear in adults, pointing to continuing phenotypic changes long after a marked decrease of Myt1l expression in juveniles.
Collapse
Affiliation(s)
- Seongbin Kim
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon 34141, Korea
| | - Hyoseon Oh
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon 34141, Korea
| | - Sang Han Choi
- Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon 16419, Korea; Department of Biomedical Engineering, Sungkyunkwan University, Suwon 16419, Korea
| | - Ye-Eun Yoo
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon 34141, Korea
| | - Young Woo Noh
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon 34141, Korea
| | - Yisul Cho
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu 41940, Korea
| | - Geun Ho Im
- Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon 16419, Korea
| | - Chanhee Lee
- Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon 16419, Korea
| | - Yusang Oh
- Department of Bio and Brain Engineering, Korea Advanced Institute for Science and Technology (KAIST), Daejeon 34141, Korea
| | - Esther Yang
- Department of Anatomy and BK21 Graduate Program, Biomedical Sciences, College of Medicine, Korea University, Seoul 02841, Korea
| | - Gyuri Kim
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon 34141, Korea
| | - Won-Suk Chung
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon 34141, Korea
| | - Hyun Kim
- Department of Anatomy and BK21 Graduate Program, Biomedical Sciences, College of Medicine, Korea University, Seoul 02841, Korea
| | - Hyojin Kang
- Division of National Supercomputing, Korea Institute of Science and Technology Information (KISTI), Daejeon 34141, Korea
| | - Yongchul Bae
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu 41940, Korea
| | - Seong-Gi Kim
- Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon 16419, Korea; Department of Biomedical Engineering, Sungkyunkwan University, Suwon 16419, Korea
| | - Eunjoon Kim
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon 34141, Korea; Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon 34141, Korea.
| |
Collapse
|
4
|
Kim H, Kim D, Cho Y, Kim K, Roh JD, Kim Y, Yang E, Kim SS, Ahn S, Kim H, Kang H, Bae Y, Kim E. Early postnatal serotonin modulation prevents adult-stage deficits in Arid1b-deficient mice through synaptic transcriptional reprogramming. Nat Commun 2022; 13:5051. [PMID: 36030255 PMCID: PMC9420115 DOI: 10.1038/s41467-022-32748-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 08/12/2022] [Indexed: 11/19/2022] Open
Abstract
Autism spectrum disorder is characterized by early postnatal symptoms, although little is known about the mechanistic deviations that produce them and whether correcting them has long-lasting preventive effects on adult-stage deficits. ARID1B, a chromatin remodeler implicated in neurodevelopmental disorders, including autism spectrum disorder, exhibits strong embryonic- and early postnatal-stage expression. We report here that Arid1b-happloinsufficient (Arid1b+/-) mice display autistic-like behaviors at juvenile and adult stages accompanied by persistent decreases in excitatory synaptic density and transmission. Chronic treatment of Arid1b+/- mice with fluoxetine, a selective serotonin-reuptake inhibitor, during the first three postnatal weeks prevents synaptic and behavioral deficits in adults. Mechanistically, these rescues accompany transcriptomic changes, including upregulation of FMRP targets and normalization of HDAC4/MEF2A-related transcriptional regulation of the synaptic proteins, SynGAP1 and Arc. These results suggest that chronic modulation of serotonergic receptors during critical early postnatal periods prevents synaptic and behavioral deficits in adult Arid1b+/- mice through transcriptional reprogramming.
Collapse
Affiliation(s)
- Hyosang Kim
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, 34141, Korea
| | - Doyoun Kim
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, 34141, Korea
| | - Yisul Cho
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, 41940, Korea
| | - Kyungdeok Kim
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, 34141, Korea
| | - Junyeop Daniel Roh
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, 34141, Korea
| | - Yangsik Kim
- Graduate School of Biomedical Engineering, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, 34141, Korea
| | - Esther Yang
- Department of Anatomy and Division of Brain Korea 21, Biomedical Science, College of Medicine, Korea University, Seoul, 02841, Korea
| | - Seong Soon Kim
- Therapeutics and Biotechnology Division, Korea Research Institute of Chemical Technology (KRICT), Daejeon, 34114, Korea
| | - Sunjoo Ahn
- Therapeutics and Biotechnology Division, Korea Research Institute of Chemical Technology (KRICT), Daejeon, 34114, Korea
| | - Hyun Kim
- Department of Anatomy and Division of Brain Korea 21, Biomedical Science, College of Medicine, Korea University, Seoul, 02841, Korea
| | - Hyojin Kang
- Division of National Supercomputing, Korea Institute of Science and Technology Information, Daejeon, 34141, Korea
| | - Yongchul Bae
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, 41940, Korea.
| | - Eunjoon Kim
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, 34141, Korea.
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, 34141, Korea.
| |
Collapse
|
5
|
Developmental changes in GABAergic and glycinergic synaptic transmission to rat motoneurons innervating jaw-closing and jaw-opening muscles. Brain Res 2021; 1777:147753. [PMID: 34914930 DOI: 10.1016/j.brainres.2021.147753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 11/03/2021] [Accepted: 12/09/2021] [Indexed: 11/21/2022]
Abstract
Trigeminal motoneurons (MNs) innervating the jaw-closing and jaw-opening muscles receive numerous inhibitory synaptic inputs from GABAergic and glycinergic neurons, which are essential for oromotor functions, such as the orofacial reflex, suckling, and mastication. The properties of the GABAergic and glycinergic inputs of these MNs undergo developmental alterations during the period in which their feeding behavior proceeds from suckling to mastication; however, the detailed characteristics of the developmental patterns of GABAergic and glycinergic transmission in these neurons remain to be elucidated. This study was conducted to investigate developmental changes in miniature inhibitory postsynaptic currents (mIPSCs) in masseter (jaw-closing) and digastric (jaw-opening) MNs using brainstem slice preparations obtained from Wistar rats on postnatal day (P)2-5, P9-12, and P14-17. The frequency and amplitude of glycinergic mIPSCs substantially increased with age in both the masseter and digastric MNs. The rise time and decay time of glycinergic mIPSCs in both MNs decreased during development. In contrast, the frequency of GABAergic components in masseter MNs was higher at P2-5 than at P14-17, whereas that in the digastric MNs remained unchanged throughout the postnatal period. The proportion of currents mediated by GABA-glycine co-transmission was higher at P2-5, and then it decreased with age in both MNs. These results suggest that characteristics related to the development of inhibitory synaptic inputs differ between jaw-closing and jaw-opening MNs and between GABAergic and glycinergic currents. These distinct developmental characteristics may contribute to the development of feeding behaviors.
Collapse
|
6
|
Paik SK, Yoshida A, Bae YC. Development of γ-aminobutyric acid-, glycine-, and glutamate-immunopositive boutons on the rat genioglossal motoneurons. Brain Struct Funct 2021; 226:889-900. [PMID: 33475854 DOI: 10.1007/s00429-021-02216-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 01/08/2021] [Indexed: 12/13/2022]
Abstract
Detailed information about the development of excitatory and inhibitory synapses on the genioglossal (GG) motoneuron may help to understand the mechanism of fine control of GG motoneuron firing and the coordinated tongue movement during postnatal development. For this, we investigated the development of γ-aminobutyric acid (GABA)-immunopositive (GABA +), glycine + (Gly +), and glutamate + (Glut +) axon terminals (boutons) on the somata of rat GG motoneurons at a postnatal day 2 (P2), P6 and P18 by retrograde labeling of GG motoneurons with horseradish peroxidase, electron microscopic postembedding immunogold staining with GABA, Gly, and Glut antisera, and quantitative analysis. The number of boutons per GG motoneuron somata and the mean length of bouton apposition, measures of bouton size and synaptic covering percentage, were significantly increased from P2/P6 to P18. The number and fraction of GABA + only boutons of all boutons decreased significantly, whereas those of Gly + only boutons increased significantly from P2/P6 to P18, suggesting developmental switch from GABAergic to glycinergic synaptic transmission. The fraction of mixed GABA +/Gly + boutons of all boutons was the highest among inhibitory bouton types throughout the postnatal development. The fractions of excitatory and inhibitory boutons of all boutons remained unchanged during postnatal development. These findings reveal a distinct developmental pattern of inhibitory synapses on the GG motoneurons different from that on spinal or trigeminal motoneurons, which may have an important role in the regulation of the precise and coordinated movements of the tongue during the maturation of the oral motor system.
Collapse
Affiliation(s)
- Sang Kyoo Paik
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, 188-1, 2-Ga, Samdeok-Dong, Jung-Gu, Daegu, 700-412, Korea
| | - Atsushi Yoshida
- Department of Oral Anatomy and Neurobiology, Graduate School of Dentistry, Osaka University, Osaka, 565-0871, Japan
| | - Yong Chul Bae
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, 188-1, 2-Ga, Samdeok-Dong, Jung-Gu, Daegu, 700-412, Korea.
| |
Collapse
|
7
|
Park H, Choi Y, Jung H, Kim S, Lee S, Han H, Kweon H, Kang S, Sim WS, Koopmans F, Yang E, Kim H, Smit AB, Bae YC, Kim E. Splice-dependent trans-synaptic PTPδ-IL1RAPL1 interaction regulates synapse formation and non-REM sleep. EMBO J 2020; 39:e104150. [PMID: 32347567 PMCID: PMC7265247 DOI: 10.15252/embj.2019104150] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 03/17/2020] [Accepted: 03/23/2020] [Indexed: 12/12/2022] Open
Abstract
Alternative splicing regulates trans‐synaptic adhesions and synapse development, but supporting in vivo evidence is limited. PTPδ, a receptor tyrosine phosphatase adhering to multiple synaptic adhesion molecules, is associated with various neuropsychiatric disorders; however, its in vivo functions remain unclear. Here, we show that PTPδ is mainly present at excitatory presynaptic sites by endogenous PTPδ tagging. Global PTPδ deletion in mice leads to input‐specific decreases in excitatory synapse development and strength. This involves tyrosine dephosphorylation and synaptic loss of IL1RAPL1, a postsynaptic partner of PTPδ requiring the PTPδ‐meA splice insert for binding. Importantly, PTPδ‐mutant mice lacking the PTPδ‐meA insert, and thus lacking the PTPδ interaction with IL1RAPL1 but not other postsynaptic partners, recapitulate biochemical and synaptic phenotypes of global PTPδ‐mutant mice. Behaviorally, both global and meA‐specific PTPδ‐mutant mice display abnormal sleep behavior and non‐REM rhythms. Therefore, alternative splicing in PTPδ regulates excitatory synapse development and sleep by modulating a specific trans‐synaptic adhesion.
Collapse
Affiliation(s)
- Haram Park
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, Korea
| | - Yeonsoo Choi
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, Korea
| | - Hwajin Jung
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, Korea
| | - Seoyeong Kim
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, Korea
| | - Suho Lee
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, Korea
| | - Hyemin Han
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, Korea
| | - Hanseul Kweon
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, Korea
| | - Suwon Kang
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, Korea
| | - Woong Seob Sim
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, Korea
| | - Frank Koopmans
- Department of Functional Genomics, CNCR, VU University and UMC Amsterdam, Amsterdam, The Netherlands.,Department of Molecular and Cellular Neurobiology, CNCR, VU University and UMC Amsterdam, Amsterdam, The Netherlands
| | - Esther Yang
- Department of Anatomy and Division of Brain Korea 21, Biomedical Science, College of Medicine, Korea University, Seoul, Korea
| | - Hyun Kim
- Department of Anatomy and Division of Brain Korea 21, Biomedical Science, College of Medicine, Korea University, Seoul, Korea
| | - August B Smit
- Department of Molecular and Cellular Neurobiology, CNCR, VU University and UMC Amsterdam, Amsterdam, The Netherlands
| | - Yong Chul Bae
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, Korea
| | - Eunjoon Kim
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, Korea.,Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, Korea
| |
Collapse
|
8
|
Park SK, Devi AP, Bae JY, Cho YS, Ko HG, Kim DY, Bae YC. Synaptic connectivity of urinary bladder afferents in the rat superficial dorsal horn and spinal parasympathetic nucleus. J Comp Neurol 2019; 527:3002-3013. [PMID: 31168784 DOI: 10.1002/cne.24725] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 05/30/2019] [Accepted: 05/30/2019] [Indexed: 11/06/2022]
Abstract
That visceral sensory afferents are functionally distinct from their somatic analogues has been known for a long time but the detailed knowledge of their synaptic connections and neurotransmitters at the first relay nucleus in the spinal cord has been limited. To provide information on these topics, we investigated the synapses and neurotransmitters of identified afferents from the urinary bladder to the superficial laminae of the rat spinal dorsal horn (DH) and the spinal parasympathetic nucleus (SPN) by tracing with horseradish peroxidase, quantitative electron microscopical analysis, and immunogold staining for GABA and glycine. In the DH, most bladder afferent boutons formed synapses with 1-2 postsynaptic dendrites, whereas in the SPN, close to a half of them formed synapses with 3-8 postsynaptic dendrites. The number of postsynaptic dendrites and dendritic spines per bladder afferent bouton, both measures of synaptic divergence and of potential for synaptic plasticity at a single bouton level, were significantly higher in the SPN than in the DH. Bladder afferent boutons frequently received inhibitory axoaxonic synapses from presynaptic endings in the DH but rarely in the SPN. The presynaptic endings were GABA- and/or glycine-immunopositive. The bouton volume, mitochondrial volume, and active zone area, all determinants of synaptic strength, of the bladder afferent boutons were positively correlated with the number of postsynaptic dendrites. These findings suggest that visceral sensory information conveyed via the urinary bladder afferents is processed differently in the DH than in the SPN, and differently from the way somatosensory information is processed in the spinal cord.
Collapse
Affiliation(s)
- Sook Kyung Park
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, South Korea
| | - Angom Pushparani Devi
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, South Korea
| | - Jin Young Bae
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, South Korea
| | - Yi Sul Cho
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, South Korea
| | - Hyoung-Gon Ko
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, South Korea
| | - Duk Yoon Kim
- Department of Urology, School of Medicine, Catholic University of Daegu, Daegu, South Korea
| | - Yong Chul Bae
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, South Korea
| |
Collapse
|
9
|
Paik SK, Yoo HI, Choi SK, Bae JY, Park SK, Bae YC. Distribution of excitatory and inhibitory axon terminals on the rat hypoglossal motoneurons. Brain Struct Funct 2019; 224:1767-1779. [PMID: 31006070 DOI: 10.1007/s00429-019-01874-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 04/11/2019] [Indexed: 12/19/2022]
Abstract
Detailed information about the excitatory and inhibitory synapses on the hypoglossal motoneurons may help understand the neural mechanism for control of the hypoglossal motoneuron excitability and hence the precise and coordinated movements of the tongue during chewing, swallowing and licking. For this, we investigated the distribution of GABA-, glycine (Gly)- and glutamate (Glut)-immunopositive (+) axon terminals on the genioglossal (GG) motoneurons by retrograde tracing, electron microscopic immunohistochemistry, and quantitative analysis. Small GG motoneurons (< 400 μm2 in cross-sectional area) had fewer primary dendrites, significantly higher nuclear/cytoplasmic ratio, and smaller membrane area covered by synaptic boutons than large GG motoneurons (> 400 μm2). The fraction of inhibitory boutons (GABA + only, Gly + only, and mixed GABA +/Gly + boutons) of all boutons was significantly higher for small GG motoneurons than for large ones, whereas the fraction of Glut + boutons was significantly higher for large GG motoneurons than for small ones. Almost all boutons (> 95%) on both small and large GG motoneurons were GABA + , Gly + or Glut + . The frequency of mixed GABA +/Gly + boutons was the highest among inhibitory boutons types for both small and large GG motoneurons. These findings may elucidate the anatomical substrate for precise regulation of the motoneuron firing required for the fine movements of the tongue, and also suggest that the excitability of small and large GG motoneurons may be regulated differently.
Collapse
Affiliation(s)
- Sang Kyoo Paik
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, 188-1, 2-Ga, Samdeok-Dong, Jung-Gu, Daegu, 700-412, South Korea
| | - Hong Il Yoo
- Department of Anatomy and Neuroscience, College of Medicine, Eulji University, 77 Gyeryong-ro 771 beon-gil, Jung-Gu, Daejeon, 34824, South Korea
| | - Seung Ki Choi
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, 188-1, 2-Ga, Samdeok-Dong, Jung-Gu, Daegu, 700-412, South Korea
| | - Jin Young Bae
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, 188-1, 2-Ga, Samdeok-Dong, Jung-Gu, Daegu, 700-412, South Korea
| | - Sook Kyung Park
- Department of Anatomy and Neurobiology, School of 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 Dentistry, Kyungpook National University, 188-1, 2-Ga, Samdeok-Dong, Jung-Gu, Daegu, 700-412, South Korea.
| |
Collapse
|
10
|
Lrfn2-Mutant Mice Display Suppressed Synaptic Plasticity and Inhibitory Synapse Development and Abnormal Social Communication and Startle Response. J Neurosci 2018; 38:5872-5887. [PMID: 29798891 DOI: 10.1523/jneurosci.3321-17.2018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 05/03/2018] [Accepted: 05/16/2018] [Indexed: 11/21/2022] Open
Abstract
SALM1 (SALM (synaptic adhesion-like molecule), also known as LRFN2 (leucine rich repeat and fibronectin type III domain containing), is a postsynaptic density (PSD)-95-interacting synaptic adhesion molecule implicated in the regulation of NMDA receptor (NMDAR) clustering largely based on in vitro data, although its in vivo functions remain unclear. Here, we found that mice lacking SALM1/LRFN2 (Lrfn2-/- mice) show a normal density of excitatory synapses but altered excitatory synaptic function, including enhanced NMDAR-dependent synaptic transmission but suppressed NMDAR-dependent synaptic plasticity in the hippocampal CA1 region. Unexpectedly, SALM1 expression was detected in both glutamatergic and GABAergic neurons and Lrfn2-/- CA1 pyramidal neurons showed decreases in the density of inhibitory synapses and the frequency of spontaneous inhibitory synaptic transmission. Behaviorally, ultrasonic vocalization was suppressed in Lrfn2-/- pups separated from their mothers and acoustic startle was enhanced, but locomotion, anxiety-like behavior, social interaction, repetitive behaviors, and learning and memory were largely normal in adult male Lrfn2-/- mice. These results suggest that SALM1/LRFN2 regulates excitatory synapse function, inhibitory synapse development, and social communication and startle behaviors in mice.SIGNIFICANCE STATEMENT Synaptic adhesion molecules regulate synapse development and function, which govern neural circuit and brain functions. The SALM/LRFN (synaptic adhesion-like molecule/leucine rich repeat and fibronectin type III domain containing) family of synaptic adhesion proteins consists of five known members for which the in vivo functions are largely unknown. Here, we characterized mice lacking SALM1/LRFN2 (SALM1 KO) known to associate with NMDA receptors (NMDARs) and found that these mice showed altered NMDAR-dependent synaptic transmission and plasticity, as expected, but unexpectedly also exhibited suppressed inhibitory synapse development and synaptic transmission. Behaviorally, SALM1 KO pups showed suppressed ultrasonic vocalization upon separation from their mothers and SALM1 KO adults showed enhanced responses to loud acoustic stimuli. These results suggest that SALM1/LRFN2 regulates excitatory synapse function, inhibitory synapse development, social communication, and acoustic startle behavior.
Collapse
|
11
|
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
|
12
|
SALM4 suppresses excitatory synapse development by cis-inhibiting trans-synaptic SALM3-LAR adhesion. Nat Commun 2016; 7:12328. [PMID: 27480238 PMCID: PMC4974644 DOI: 10.1038/ncomms12328] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 06/23/2016] [Indexed: 12/01/2022] Open
Abstract
Synaptic adhesion molecules regulate various aspects of synapse development, function and plasticity. These functions mainly involve trans-synaptic interactions and positive regulations, whereas cis-interactions and negative regulation are less understood. Here we report that SALM4, a member of the SALM/Lrfn family of synaptic adhesion molecules, suppresses excitatory synapse development through cis inhibition of SALM3, another SALM family protein with synaptogenic activity. Salm4-mutant (Salm4−/−) mice show increased excitatory synapse numbers in the hippocampus. SALM4 cis-interacts with SALM3, inhibits trans-synaptic SALM3 interaction with presynaptic LAR family receptor tyrosine phosphatases and suppresses SALM3-dependent presynaptic differentiation. Importantly, deletion of Salm3 in Salm4−/− mice (Salm3−/−; Salm4−/−) normalizes the increased excitatory synapse number. These results suggest that SALM4 negatively regulates excitatory synapses via cis inhibition of the trans-synaptic SALM3–LAR adhesion. Synaptic adhesion molecules regulate synapse development and function by both cis and trans-interactions. Here, Lie et al. show that postsynaptic SALM4 regulates excitatory synapse numbers by cis inhibition of the SALM3-LAR transynaptic interaction.
Collapse
|
13
|
Expression of glycine receptor alpha 3 in the rat trigeminal neurons and central boutons in the brainstem. Brain Struct Funct 2016; 221:4601-4613. [PMID: 26832918 DOI: 10.1007/s00429-016-1190-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 01/14/2016] [Indexed: 10/22/2022]
Abstract
Increasing evidence shows that the homomeric glycine receptor is expressed in axon terminals and is involved in the presynaptic modulation of transmitter release. However, little is known about the expression of the glycine receptor, implicated in the presynaptic modulation of sensory transmission in the primary somatosensory neurons and their central boutons. To address this, we investigated the expression of glycine receptor subunit alpha 3 (GlyRα3) in the neurons in the trigeminal ganglion and axon terminals in the 1st relay nucleus of the brainstem by light- and electron-microscopic immunohistochemistry. Trigeminal primary sensory neurons were GlyRα3-immunopositive/gephyrin-immunonegative (indicating homomeric GlyR), whereas GlyRα3/gephyrin immunoreactivity (indicating heteromeric GlyR) was observed in dendrites. GlyRα3 immunoreactivity was also found in the central boutons of primary afferents but far from the presynaptic site and in dendrites at subsynaptic sites. Boutons expressing GlyRα3 contained small round vesicles, formed asymmetric synapses with dendrites and were immunoreactive for glutamate. These findings suggest that trigeminal primary afferent boutons receive presynaptic modulation via homomeric, extrasynaptic GlyRα3, and that different subtypes of GlyR may be involved in pre- and postsynaptic inhibition.
Collapse
|
14
|
Central connectivity of the chorda tympani afferent terminals in the rat rostral nucleus of the solitary tract. Brain Struct Funct 2014; 221:1125-37. [PMID: 25503820 DOI: 10.1007/s00429-014-0959-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Accepted: 12/06/2014] [Indexed: 10/24/2022]
|
15
|
Park SK, Kim JH, Yang ES, Ahn DK, Moon C, Bae YC. Ultrastructure and synaptic connectivity of main and accessory olfactory bulb efferent projections terminating in the rat anterior piriform cortex and medial amygdala. Brain Struct Funct 2013; 219:1603-13. [DOI: 10.1007/s00429-013-0588-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 05/22/2013] [Indexed: 12/20/2022]
|
16
|
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]
|
17
|
Lee D, Lee HW, Hong S, Choi BI, Kim HW, Han SB, Kim IH, Bae JY, Bae YC, Rhyu IJ, Sun W, Kim H. Inositol 1,4,5-trisphosphate 3-kinase A is a novel microtubule-associated protein: PKA-dependent phosphoregulation of microtubule binding affinity. J Biol Chem 2012; 287:15981-95. [PMID: 22389500 DOI: 10.1074/jbc.m112.344101] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Inositol 1,4,5-trisphosphate 3-kinase A (IP(3)K-A) is a brain specific and F-actin-binding protein. We recently demonstrated that IP(3)K-A modulates a structural reorganization of dendritic spines through F-actin remodeling, which is required for synaptic plasticity and memory formation in brain. However, detailed functions of IP(3)K-A and its regulatory mechanisms involved in the neuronal cytoskeletal dynamics still remain unknown. In the present study, we identified tubulin as a candidate of IP(3)K-A-binding protein through proteomic screening. By various in vitro and in vivo approaches, we demonstrated that IP(3)K-A was a novel microtubule-associated protein (MAP), and the N terminus of IP(3)K-A was a critical region for direct binding to tubulin in dendritic shaft of hippocampal neurons. Moreover, PKA phosphorylated Ser-119 within IP(3)K-A, leading to a significant reduction of microtubule binding affinity. These results suggest that PKA-dependent phosphorylation and microtubule binding of IP(3)K-A are involved in its regulatory mechanism for activity-dependent neuronal events such as local calcium signaling and its synaptic targeting.
Collapse
Affiliation(s)
- Dongmin Lee
- Department of Anatomy, College of Medicine, Korea University, Brain Korea 21, Seoul 136-705, Korea
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Paik SK, Kwak WK, Bae JY, Na YK, Park SY, Yi HW, Ahn DK, Ottersen OP, Yoshida A, Bae YC. Development of γ-aminobutyric acid-, glycine-, and glutamate-immunopositive boutons on rat jaw-opening motoneurons. J Comp Neurol 2012; 520:1212-26. [DOI: 10.1002/cne.22771] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
19
|
Paik SK, Park SK, Jin JK, Bae JY, Choi SJ, Yoshida A, Ahn DK, Bae YC. Ultrastructural analysis of glutamate-immunopositive synapses onto the rat jaw-closing motoneurons during postnatal development. J Neurosci Res 2010; 89:153-61. [DOI: 10.1002/jnr.22544] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Revised: 09/20/2010] [Accepted: 10/04/2010] [Indexed: 11/07/2022]
|
20
|
Properties of synaptic transmission from the reticular formation dorsal to the facial nucleus to trigeminal motoneurons during early postnatal development in rats. Neuroscience 2010; 166:1008-22. [PMID: 20060035 DOI: 10.1016/j.neuroscience.2009.12.065] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Revised: 11/30/2009] [Accepted: 12/26/2009] [Indexed: 11/20/2022]
Abstract
We previously reported that electrical stimulation of the reticular formation dorsal to the facial nucleus (RdVII) elicited excitatory masseter responses at short latencies and that RdVII neurons were antidromically activated by stimulation of the trigeminal motor nucleus (MoV), suggesting that excitatory premotor neurons targeting the MoV are likely located in the RdVII. We thus examined the properties of synaptic transmission from the RdVII to jaw-closing and jaw-opening motoneurons in horizontal brainstem preparations from developing rats using voltage-sensitive dye, patch-clamp recordings and laser photostimulation. Electrical stimulation of the RdVII evoked optical responses in the MoV. Combined bath application of the non-N-methyl-d-aspartate (non-NMDA) receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), and the NMDA receptor antagonist DL-2-amino-5-phosphonopentanoic acid (APV) reduced these optical responses, and addition of the glycine receptor antagonist strychnine and the GABA(A) receptor antagonist bicuculline further reduced the remaining responses. Electrical stimulation of the RdVII evoked postsynaptic currents (PSCs) in all 19 masseter motoneurons tested in postnatal day (P)1-4 rats, and application of CNQX and the NMDA receptor antagonist (+/-)-3(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid (CPP) reduced the PSC amplitudes by more than 50%. In the presence of CNQX and CPP, the GABA(A) receptor antagonist SR95531 further reduced PSC amplitude, and addition of strychnine abolished the remaining PSCs. Photostimulation of the RdVII with caged glutamate also evoked PSCs in masseter motoneurons of P3-4 rats. In P8-11 rats, electrical stimulation of the RdVII also evoked PSCs in all 14 masseter motoneurons tested, and the effects of the antagonists on the PSCs were similar to those in P1-4 rats. On the other hand, RdVII stimulation evoked PSCs in only three of 16 digastric motoneurons tested. These results suggest that both neonatal and juvenile jaw-closing motoneurons receive strong synaptic inputs from the RdVII through activation of glutamate, glycine and GABA(A) receptors, whereas inputs from the RdVII to jaw-opening motoneurons seem to be weak.
Collapse
|
21
|
Paik SK, Lee HJ, Choi MK, Cho YS, Park MJ, Moritani M, Yoshida A, Kim YS, Bae YC. Ultrastructural analysis of glutamate-, GABA-, and glycine-immunopositive boutons from supratrigeminal premotoneurons in the rat trigeminal motor nucleus. J Neurosci Res 2009; 87:1115-22. [PMID: 19006082 DOI: 10.1002/jnr.21929] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The supratrigeminal region (Vsup) is important for coordination of smooth jaw movement. However, little is known about the synaptic connections of the Vsup premotoneurons with the trigeminal motor neurons. In the present study, we examined axon terminals of Vsup premotoneurons in the contralateral trigeminal motor nucleus (Vmo) by a combination of anterograde tracing with cholera toxin B-horseradish peroxidase (CTB-HRP), postembedding immunohistochemistry for the amino acid transmitters glutamate, GABA, and glycine, and electron microscopy. Tracer injections resulted in anterograde labeling of axon terminals of the Vsup premotoneurons in the motor trigeminal nucleus (Vmo). The labeled boutons in Vmo exhibited immunoreactivity for glutamate, GABA, or glycine: glutamate-immunopositive boutons (69%) were more frequently observed than GABA- or glycine-immunopositive boutons (19% and 12%, respectively). Although most labeled boutons (97%) made synaptic contacts with a single postsynaptic dendrite, a few glutamate-immunopositive boutons (3%) showed synaptic contact with two dendrites. No labeled boutons participated in axoaxonic synaptic contacts. Most labeled boutons (78%) were presynaptic to dendritic shafts, and the remaining 22% were presynaptic to somata or primary dendrites. A large proportion of GABA- or glycine-immunopositive boutons (40%) were presynaptic to somata or primary dendrites, whereas most glutamate-immunopositive boutons (86%) were presynaptic to dendritic shafts. These results indicate that axon terminals of Vsup premotoneurons show simple synaptic connection with Vmo neurons. This may provide the anatomical basis for the neural information processing responsible for jaw movement control.
Collapse
Affiliation(s)
- Sang Kyoo Paik
- Department of Oral Anatomy and Neurobiology, School of Dentistry, BK21, Kyungpook National University, Daegu, Korea
| | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Moon YS, Paik SK, Seo JH, Yi HW, Cho YS, Moritani M, Yoshida A, Ahn CDK, Kim YS, Bae YC. GABA- and glycine-like immunoreactivity in axonal endings presynaptic to the vibrissa afferents in the cat trigeminal interpolar nucleus. Neuroscience 2008; 152:138-45. [PMID: 18248903 DOI: 10.1016/j.neuroscience.2007.11.033] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2007] [Revised: 11/20/2007] [Accepted: 11/21/2007] [Indexed: 10/22/2022]
Abstract
The goal of this study was to analyze the synaptic interaction of primary afferents with GABA- and/or glycine-immunopositive presynaptic endings in the cat trigeminal interpolar nucleus (Vi). Fast adapting vibrissa afferents were labeled by intra-axonal injections of horseradish peroxidase. Postembedding immunogold labeling on serially cut ultrathin sections and quantitative ultrastructural analysis of the labeled boutons and their presynaptic endings (p-endings) in the Vi were performed. The majority of p-endings presynaptic to labeled boutons (83%) were immunopositive for both GABA and glycine and 8% were immunopositive for glycine alone. A small fraction of p-endings were immunopositive for GABA alone (4%) or immunonegative for both GABA and glycine (4%). Ultrastructural parameters related to synaptic release, i.e. bouton volume, mitochondrial volume, and active zone area, were significantly larger in the labeled boutons of primary afferents than in the p-endings. The volume of labeled boutons was positively correlated with the number of the postsynaptic dendrites and p-endings. In addition, fairly large-sized labeled boutons and p-endings were frequently observed in the Vi. These results reveal that large majority of vibrissa afferents in the Vi are presynaptically modulated by interneurons immunopositive for both GABA and glycine, and suggest that the Vi plays a distinct role in the processing of orofacial sensory information, different from that of other trigeminal sensory nuclei.
Collapse
Affiliation(s)
- Y S Moon
- Department of Anatomy, School of Medicine, Catholic University of Daegu, 3056-6, Daemyong-Dong, Nam-Gu, Daegu 705-718, Korea
| | | | | | | | | | | | | | | | | | | |
Collapse
|