1
|
Huff AD, Karlen-Amarante M, Oliveira LM, Ramirez JM. Chronic intermittent hypoxia reveals role of the Postinspiratory Complex in the mediation of normal swallow production. eLife 2024; 12:RP92175. [PMID: 38655918 DOI: 10.7554/elife.92175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024] Open
Abstract
Obstructive sleep apnea (OSA) is a prevalent sleep-related breathing disorder that results in multiple bouts of intermittent hypoxia. OSA has many neurological and systemic comorbidities, including dysphagia, or disordered swallow, and discoordination with breathing. However, the mechanism in which chronic intermittent hypoxia (CIH) causes dysphagia is unknown. Recently, we showed the postinspiratory complex (PiCo) acts as an interface between the swallow pattern generator (SPG) and the inspiratory rhythm generator, the preBötzinger complex, to regulate proper swallow-breathing coordination (Huff et al., 2023). PiCo is characterized by interneurons co-expressing transporters for glutamate (Vglut2) and acetylcholine (ChAT). Here we show that optogenetic stimulation of ChATcre:Ai32, Vglut2cre:Ai32, and ChATcre:Vglut2FlpO:ChR2 mice exposed to CIH does not alter swallow-breathing coordination, but unexpectedly disrupts swallow behavior via triggering variable swallow motor patterns. This suggests that glutamatergic-cholinergic neurons in PiCo are not only critical for the regulation of swallow-breathing coordination, but also play an important role in the modulation of swallow motor patterning. Our study also suggests that swallow disruption, as seen in OSA, involves central nervous mechanisms interfering with swallow motor patterning and laryngeal activation. These findings are crucial for understanding the mechanisms underlying dysphagia, both in OSA and other breathing and neurological disorders.
Collapse
Affiliation(s)
- Alyssa D Huff
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, United States
| | - Marlusa Karlen-Amarante
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, United States
| | - Luiz M Oliveira
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, United States
| | - Jan-Marino Ramirez
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, United States
- Department of Neurological Surgery, University of Washington School of Medicine, Seattle, United States
| |
Collapse
|
2
|
Warlow SM, Singhal SM, Hollon NG, Faget L, Dowlat DS, Zell V, Hunker AC, Zweifel LS, Hnasko TS. Mesoaccumbal glutamate neurons drive reward via glutamate release but aversion via dopamine co-release. Neuron 2024; 112:488-499.e5. [PMID: 38086374 PMCID: PMC10922836 DOI: 10.1016/j.neuron.2023.11.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 06/22/2023] [Accepted: 11/06/2023] [Indexed: 02/10/2024]
Abstract
Ventral tegmental area (VTA) projections to the nucleus accumbens (NAc) drive reward-related motivation. Although dopamine neurons are predominant, a substantial glutamatergic projection is also present, and a subset of these co-release both dopamine and glutamate. Optogenetic stimulation of VTA glutamate neurons not only supports self-stimulation but can also induce avoidance behavior, even in the same assay. Here, we parsed the selective contribution of glutamate or dopamine co-release from VTA glutamate neurons to reinforcement and avoidance. We expressed channelrhodopsin-2 (ChR2) in mouse VTA glutamate neurons in combination with CRISPR-Cas9 to disrupt either the gene encoding vesicular glutamate transporter 2 (VGLUT2) or tyrosine hydroxylase (Th). Selective disruption of VGLUT2 abolished optogenetic self-stimulation but left real-time place avoidance intact, whereas CRISPR-Cas9 deletion of Th preserved self-stimulation but abolished place avoidance. Our results demonstrate that glutamate release from VTA glutamate neurons is positively reinforcing but that dopamine release from VTA glutamate neurons can induce avoidance behavior.
Collapse
Affiliation(s)
- Shelley M Warlow
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Sarthak M Singhal
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Nick G Hollon
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Lauren Faget
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Dina S Dowlat
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Vivien Zell
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Avery C Hunker
- Department of Pharmacology, University of Washington, Seattle, WA, USA
| | - Larry S Zweifel
- Department of Pharmacology, University of Washington, Seattle, WA, USA
| | - Thomas S Hnasko
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA; Veterans Affairs San Diego Healthcare System, San Diego, CA, USA.
| |
Collapse
|
3
|
Sankhe AS, Bordeleau D, Alfonso DIM, Wittman G, Chee MJ. Loss of glutamatergic signalling from MCH neurons reduced anxiety-like behaviours in novel environments. J Neuroendocrinol 2023; 35:e13222. [PMID: 36529144 DOI: 10.1111/jne.13222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 11/10/2022] [Accepted: 11/23/2022] [Indexed: 12/02/2022]
Abstract
Melanin-concentrating hormone (MCH) neurons within the hypothalamus are heterogeneous and can coexpress additional neuropeptides and transmitters. The majority of MCH neurons express vesicular transporters to package glutamate for synaptic release, and MCH neurons can directly innervate downstream neurons via glutamate release. Although glutamatergic signalling from MCH neurons may support physiological and behavioural roles that are independent of MCH (e.g., in glucose homeostasis and nutrient-sensing), it can also mediate similar roles to MCH in the regulation of energy balance. In addition to energy balance, the MCH system has also been implicated in mood disorders, as MCH receptor antagonists have anxiolytic and anti-depressive effects. However, the contribution of glutamatergic signalling from MCH neurons to mood-related functions have not been investigated. We crossed Mch-cre mice with floxed-Vglut2 mice to delete the expression of the vesicular glutamate transporter 2 (Vglut2) and disable glutamatergic signalling specifically from MCH neurons. The resulting Mch-Vglut2-KO mice showed Vglut2 deletion from over 75% of MCH neurons, and although we did not observe changes in depressive-like behaviours, we found that Mch-Vglut2-KO mice displayed anxiety-like behaviours. Mch-Vglut2-KO mice showed reduced exploratory activity when placed in a new cage and were quicker to consume food placed in the centre of a novel open arena. These findings showed that Vglut2 deletion from MCH neurons resulted in anxiolytic actions and suggested that the anxiogenic effects of glutamate are similar to those of the MCH peptide. Taken together, these findings suggest that glutamate and MCH may synergize to regulate and promote anxiety-like behaviour.
Collapse
Affiliation(s)
- Aditi S Sankhe
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada
| | - Dillon Bordeleau
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada
| | | | - Gábor Wittman
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Tufts Medical Center, Boston, MA, USA
| | - Melissa J Chee
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada
| |
Collapse
|
4
|
Steinkellner T, Conrad WS, Kovacs I, Rissman RA, Lee EB, Trojanowski JQ, Freyberg Z, Roy S, Luk KC, Lee VM, Hnasko TS. Dopamine neurons exhibit emergent glutamatergic identity in Parkinson's disease. Brain 2022; 145:879-886. [PMID: 35258081 PMCID: PMC9050538 DOI: 10.1093/brain/awab373] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 09/02/2021] [Accepted: 09/02/2021] [Indexed: 01/07/2023] Open
Abstract
Loss of midbrain dopamine neurons causes the cardinal symptoms of Parkinson's disease. However, not all dopamine neurons are equally vulnerable and a better understanding of the cell-type specific properties relating to selective dopamine neuron degeneration is needed. Most midbrain dopamine neurons express the vesicular glutamate transporter VGLUT2 during development and a subset continue to express low levels of VGLUT2 in adulthood, enabling the co-release of glutamate. Moreover, VGLUT2 expression in dopamine neurons can be neuroprotective since its genetic disruption was shown to sensitize dopamine neurons to neurotoxins. Here, we show that in response to toxic insult, and in two distinct models of alpha-synuclein stress, VGLUT2 dopamine neurons were resilient to degeneration. Dopamine neurons expressing VGLUT2 were enriched whether or not insult induced dopamine neuron loss, suggesting that while VGLUT2 dopamine neurons are more resilient, VGLUT2 expression can also be transcriptionally upregulated by injury. Finally, we observed that VGLUT2 expression was enhanced in surviving dopamine neurons from post-mortem Parkinson's disease individuals. These data indicate that emergence of a glutamatergic identity in dopamine neurons may be part of a neuroprotective response in Parkinson's disease.
Collapse
Affiliation(s)
- Thomas Steinkellner
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
- Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Austria
| | - William S Conrad
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Imre Kovacs
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Robert A Rissman
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA
| | - Edward B Lee
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - John Q Trojanowski
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Zachary Freyberg
- Departments of Psychiatry and Cell Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Subhojit Roy
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
- Department of Pathology, University of California, San Diego, La Jolla, CA, USA
| | - Kelvin C Luk
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Virginia M Lee
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Thomas S Hnasko
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA
| |
Collapse
|
5
|
Sheng ZF, Zhang H, Zheng P, Chen S, Gu Z, Zhou JJ, Phaup JG, Chang HM, Yeh ETH, Pan HL, Li DP. Impaired Kv7 channel activity in the central amygdala contributes to elevated sympathetic outflow in hypertension. Cardiovasc Res 2022; 118:585-596. [PMID: 33512443 PMCID: PMC8803073 DOI: 10.1093/cvr/cvab031] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 11/11/2020] [Accepted: 01/25/2021] [Indexed: 11/13/2022] Open
Abstract
AIMS Elevated sympathetic outflow is associated with primary hypertension. However, the mechanisms involved in heightened sympathetic outflow in hypertension are unclear. The central amygdala (CeA) regulates autonomic components of emotions through projections to the brainstem. The neuronal Kv7 channel is a non-inactivating voltage-dependent K+ channel encoded by KCNQ2/3 genes involved in stabilizing the neuronal membrane potential and regulating neuronal excitability. In this study, we investigated if altered Kv7 channel activity in the CeA contributes to heightened sympathetic outflow in hypertension. METHODS AND RESULTS The mRNA and protein expression levels of Kv7.2/Kv7.3 in the CeA were significantly reduced in spontaneously hypertensive rats (SHRs) compared with Wistar-Kyoto (WKY) rats. Lowering blood pressure with coeliac ganglionectomy in SHRs did not alter Kv7.2 and Kv7.3 channel expression levels in the CeA. Fluospheres were injected into the rostral ventrolateral medulla (RVLM) to retrogradely label CeA neurons projecting to the RVLM (CeA-RVLM neurons). Kv7 channel currents recorded from CeA-RVLM neurons in brain slices were much smaller in SHRs than in WKY rats. Furthermore, the basal firing activity of CeA-RVLM neurons was significantly greater in SHRs than in WKY rats. Bath application of specific Kv7 channel blocker 10, 10-bis (4-pyridinylmethyl)-9(10H)-anthracnose (XE-991) increased the excitability of CeA-RVLM neurons in WKY rats, but not in SHRs. Microinjection of XE-991 into the CeA increased arterial blood pressure (ABP) and renal sympathetic nerve activity (RSNA), while microinjection of Kv7 channel opener QO-58 decreased ABP and RSNA, in anaesthetized WKY rats but not SHRs. CONCLUSIONS Our findings suggest that diminished Kv7 channel activity in the CeA contributes to elevated sympathetic outflow in primary hypertension. This novel information provides new mechanistic insight into the pathogenesis of neurogenic hypertension.
Collapse
Affiliation(s)
- Zhao-Fu Sheng
- Center for Precision Medicine, Department of Medicine, School of Medicine, University of Missouri, 1 Hospital Drive, Columbia, MO 65212, USA
| | - Hua Zhang
- Center for Precision Medicine, Department of Medicine, School of Medicine, University of Missouri, 1 Hospital Drive, Columbia, MO 65212, USA
| | - PeiRu Zheng
- Center for Precision Medicine, Department of Medicine, School of Medicine, University of Missouri, 1 Hospital Drive, Columbia, MO 65212, USA
| | - Shanyan Chen
- Department of Pathology and Anatomical Sciences, School of Medicine, University of Missouri, 1 Hospital Drive, Columbia, MO 65212, USA
| | - Zezong Gu
- Department of Pathology and Anatomical Sciences, School of Medicine, University of Missouri, 1 Hospital Drive, Columbia, MO 65212, USA
| | - Jing-Jing Zhou
- Department of Anesthesiology and Perioperative Medicine, The University of Texas, MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
| | - Jeffery G Phaup
- Center for Precision Medicine, Department of Medicine, School of Medicine, University of Missouri, 1 Hospital Drive, Columbia, MO 65212, USA
| | - Hui-Ming Chang
- Departments of Pharmacology and Toxicology and Internal Medicine, The University of Arkansas for Medical Sciences, 4301 West Markham St., Little Rock, AR 72205, USA
| | - Edward T H Yeh
- Departments of Pharmacology and Toxicology and Internal Medicine, The University of Arkansas for Medical Sciences, 4301 West Markham St., Little Rock, AR 72205, USA
| | - Hui-Lin Pan
- Department of Anesthesiology and Perioperative Medicine, The University of Texas, MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
| | - De-Pei Li
- Center for Precision Medicine, Department of Medicine, School of Medicine, University of Missouri, 1 Hospital Drive, Columbia, MO 65212, USA
| |
Collapse
|
6
|
Zhang L, Wang J, Niu C, Zhang Y, Zhu T, Huang D, Ma J, Sun H, Gamper N, Du X, Zhang H. Activation of parabrachial nucleus - ventral tegmental area pathway underlies the comorbid depression in chronic neuropathic pain in mice. Cell Rep 2021; 37:109936. [PMID: 34731609 PMCID: PMC8578703 DOI: 10.1016/j.celrep.2021.109936] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 07/31/2021] [Accepted: 10/13/2021] [Indexed: 11/26/2022] Open
Abstract
Depression symptoms are often found in patients suffering from chronic pain, a phenomenon that is yet to be understood mechanistically. Here, we systematically investigate the cellular mechanisms and circuits underlying the chronic-pain-induced depression behavior. We show that the development of chronic pain is accompanied by depressive-like behaviors in a mouse model of trigeminal neuralgia. In parallel, we observe increased activity of the dopaminergic (DA) neuron in the midbrain ventral tegmental area (VTA), and inhibition of this elevated VTA DA neuron activity reverses the behavioral manifestations of depression. Further studies establish a pathway of glutamatergic projections from the spinal trigeminal subnucleus caudalis (Sp5C) to the lateral parabrachial nucleus (LPBN) and then to the VTA. These glutamatergic projections form a direct circuit that controls the development of the depression-like behavior under the state of the chronic neuropathic pain.
Collapse
Affiliation(s)
- Ludi Zhang
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Jing Wang
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei 050017, China; Department of Pharmacochemistry, Hebei University of Chinese Medicine, Shijiazhuang, Hebei 050091, China
| | - Chenxu Niu
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Yu Zhang
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Tiantian Zhu
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Dongyang Huang
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Jing Ma
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Hui Sun
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei 050017, China; Department of Physiology, Binzhou Medical University, YanTai, Shandong 264003, China
| | - Nikita Gamper
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei 050017, China; School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Xiaona Du
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Hailin Zhang
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei 050017, China.
| |
Collapse
|
7
|
van der Heijden ME, Lackey EP, Perez R, Ișleyen FS, Brown AM, Donofrio SG, Lin T, Zoghbi HY, Sillitoe RV. Maturation of Purkinje cell firing properties relies on neurogenesis of excitatory neurons. eLife 2021; 10:e68045. [PMID: 34542409 PMCID: PMC8452305 DOI: 10.7554/elife.68045] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 08/31/2021] [Indexed: 01/18/2023] Open
Abstract
Preterm infants that suffer cerebellar insults often develop motor disorders and cognitive difficulty. Excitatory granule cells, the most numerous neuron type in the brain, are especially vulnerable and likely instigate disease by impairing the function of their targets, the Purkinje cells. Here, we use regional genetic manipulations and in vivo electrophysiology to test whether excitatory neurons establish the firing properties of Purkinje cells during postnatal mouse development. We generated mutant mice that lack the majority of excitatory cerebellar neurons and tracked the structural and functional consequences on Purkinje cells. We reveal that Purkinje cells fail to acquire their typical morphology and connectivity, and that the concomitant transformation of Purkinje cell firing activity does not occur either. We also show that our mutant pups have impaired motor behaviors and vocal skills. These data argue that excitatory cerebellar neurons define the maturation time-window for postnatal Purkinje cell functions and refine cerebellar-dependent behaviors.
Collapse
Affiliation(s)
- Meike E van der Heijden
- Department of Pathology and Immunology, Baylor College of MedicineHoustonUnited States
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
| | - Elizabeth P Lackey
- Department of Pathology and Immunology, Baylor College of MedicineHoustonUnited States
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
| | - Ross Perez
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
| | - Fatma S Ișleyen
- Department of Pathology and Immunology, Baylor College of MedicineHoustonUnited States
- Program in Developmental Biology, Baylor College of MedicineHoustonUnited States
| | - Amanda M Brown
- Department of Pathology and Immunology, Baylor College of MedicineHoustonUnited States
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
| | - Sarah G Donofrio
- Department of Pathology and Immunology, Baylor College of MedicineHoustonUnited States
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
| | - Tao Lin
- Department of Pathology and Immunology, Baylor College of MedicineHoustonUnited States
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
| | - Huda Y Zoghbi
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Program in Developmental Biology, Baylor College of MedicineHoustonUnited States
- Howard Hughes Medical Institute, Department of Molecular and Human Genetics, Baylor College of MedicineHoustonUnited States
| | - Roy V Sillitoe
- Department of Pathology and Immunology, Baylor College of MedicineHoustonUnited States
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Program in Developmental Biology, Baylor College of MedicineHoustonUnited States
- Development, Disease Models and Therapeutics Graduate Program, Baylor College of MedicineHoustonUnited States
| |
Collapse
|
8
|
McKenna JT, Yang C, Bellio T, Anderson-Chernishof MB, Gamble MC, Hulverson A, McCoy JG, Winston S, Hodges E, Katsuki F, McNally JM, Basheer R, Brown RE. Characterization of basal forebrain glutamate neurons suggests a role in control of arousal and avoidance behavior. Brain Struct Funct 2021; 226:1755-1778. [PMID: 33997911 PMCID: PMC8340131 DOI: 10.1007/s00429-021-02288-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 05/05/2021] [Indexed: 12/25/2022]
Abstract
The basal forebrain (BF) is involved in arousal, attention, and reward processing but the role of individual BF neuronal subtypes is still being uncovered. Glutamatergic neurons are the least well-understood of the three main BF neurotransmitter phenotypes. Here we analyzed the distribution, size, calcium-binding protein content and projections of the major group of BF glutamatergic neurons expressing the vesicular glutamate transporter subtype 2 (vGluT2) and tested the functional effect of activating them. Mice expressing Cre recombinase under the control of the vGluT2 promoter were crossed with a reporter strain expressing the red fluorescent protein, tdTomato, to generate vGluT2-cre-tdTomato mice. Immunohistochemical staining for choline acetyltransferase and a cross with mice expressing green fluorescent protein selectively in GABAergic neurons confirmed that cholinergic, GABAergic and vGluT2+ neurons represent distinct BF subpopulations. Subsets of BF vGluT2+ neurons expressed the calcium-binding proteins calbindin or calretinin, suggesting that multiple subtypes of BF vGluT2+ neurons exist. Anterograde tracing using adeno-associated viral vectors expressing channelrhodopsin2-enhanced yellow fluorescent fusion proteins revealed major projections of BF vGluT2+ neurons to neighboring BF cholinergic and parvalbumin neurons, as well as to extra-BF areas involved in the control of arousal or aversive/rewarding behavior such as the lateral habenula and ventral tegmental area. Optogenetic activation of BF vGluT2+ neurons elicited a striking avoidance of the area where stimulation was given, whereas stimulation of BF parvalbumin or cholinergic neurons did not. Together with previous optogenetic findings suggesting an arousal-promoting role, our findings suggest that BF vGluT2 neurons play a dual role in promoting wakefulness and avoidance behavior.
Collapse
Affiliation(s)
- James T McKenna
- Laboratory of Neuroscience, Dept. of Psychiatry, VA Boston Healthcare System and Harvard Medical School, 1400 VFW Parkway, West Roxbury, MA, 02132, USA
| | - Chun Yang
- Laboratory of Neuroscience, Dept. of Psychiatry, VA Boston Healthcare System and Harvard Medical School, 1400 VFW Parkway, West Roxbury, MA, 02132, USA
| | - Thomas Bellio
- Laboratory of Neuroscience, Dept. of Psychiatry, VA Boston Healthcare System and Harvard Medical School, 1400 VFW Parkway, West Roxbury, MA, 02132, USA
- Stonehill College, Easton, MA, 02357, USA
| | - Marissa B Anderson-Chernishof
- Laboratory of Neuroscience, Dept. of Psychiatry, VA Boston Healthcare System and Harvard Medical School, 1400 VFW Parkway, West Roxbury, MA, 02132, USA
| | - Mackenzie C Gamble
- Laboratory of Neuroscience, Dept. of Psychiatry, VA Boston Healthcare System and Harvard Medical School, 1400 VFW Parkway, West Roxbury, MA, 02132, USA
- Stonehill College, Easton, MA, 02357, USA
| | - Abigail Hulverson
- Laboratory of Neuroscience, Dept. of Psychiatry, VA Boston Healthcare System and Harvard Medical School, 1400 VFW Parkway, West Roxbury, MA, 02132, USA
- Stonehill College, Easton, MA, 02357, USA
| | - John G McCoy
- Laboratory of Neuroscience, Dept. of Psychiatry, VA Boston Healthcare System and Harvard Medical School, 1400 VFW Parkway, West Roxbury, MA, 02132, USA
- Stonehill College, Easton, MA, 02357, USA
| | - Stuart Winston
- Laboratory of Neuroscience, Dept. of Psychiatry, VA Boston Healthcare System and Harvard Medical School, 1400 VFW Parkway, West Roxbury, MA, 02132, USA
| | - Erik Hodges
- Laboratory of Neuroscience, Dept. of Psychiatry, VA Boston Healthcare System and Harvard Medical School, 1400 VFW Parkway, West Roxbury, MA, 02132, USA
| | - Fumi Katsuki
- Laboratory of Neuroscience, Dept. of Psychiatry, VA Boston Healthcare System and Harvard Medical School, 1400 VFW Parkway, West Roxbury, MA, 02132, USA
| | - James M McNally
- Laboratory of Neuroscience, Dept. of Psychiatry, VA Boston Healthcare System and Harvard Medical School, 1400 VFW Parkway, West Roxbury, MA, 02132, USA
| | - Radhika Basheer
- Laboratory of Neuroscience, Dept. of Psychiatry, VA Boston Healthcare System and Harvard Medical School, 1400 VFW Parkway, West Roxbury, MA, 02132, USA
| | - Ritchie E Brown
- Laboratory of Neuroscience, Dept. of Psychiatry, VA Boston Healthcare System and Harvard Medical School, 1400 VFW Parkway, West Roxbury, MA, 02132, USA.
| |
Collapse
|
9
|
Guo T, Patel S, Shah D, Chi L, Emadi S, Pierce DM, Han M, Brumovsky PR, Feng B. Optical clearing reveals TNBS-induced morphological changes of VGLUT2-positive nerve fibers in mouse colorectum. Am J Physiol Gastrointest Liver Physiol 2021; 320:G644-G657. [PMID: 33533318 PMCID: PMC8238166 DOI: 10.1152/ajpgi.00363.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 01/12/2021] [Accepted: 01/27/2021] [Indexed: 01/31/2023]
Abstract
Colorectal hypersensitivity and sensitization of both mechanosensitive and mechanically insensitive afferents develop after intracolonic instillation of 2,4,6-trinitrobenzenesulfonic acid (TNBS) in the mouse, a model of postinfectious irritable bowel syndrome. In mice in which ∼80% of extrinsic colorectal afferents were labeled genetically using the promotor for vesicular glutamate transporter type 2 (VGLUT2), we systematically quantified the morphology of VGLUT2-positive axons in mouse colorectum 7-28 days following intracolonic TNBS treatment. After removal, the colorectum was distended (20 mmHg), fixed with paraformaldehyde, and optically cleared to image VGLUT2-positive axons throughout the colorectal wall thickness. We conducted vector path tracing of individual axons to allow systematic quantification of nerve fiber density and shape. Abundant VGLUT2-positive nerve fibers were present in most layers of the colorectum, except the serosal and longitudinal muscular layers. A small percentage of VGLUT2-positive myenteric plexus neurons was also detected. Intracolonic TNBS treatment significantly reduced the number of VGLUT2-positive nerve fibers in submucosal, myenteric plexus, and mucosal layers at day 7 post-TNBS, which mostly recovered by day 28. We also found that almost all fibers in the submucosa were meandering and curvy, with ∼10% showing pronounced curviness (quantified by the linearity index). TNBS treatment resulted in a significant reduction of the proportions of pronounced curvy fibers in the rectal region at 28 days post-TNBS. Altogether, the present morphological study reveals profound changes in the distribution of VGLUT2-positive fibers in mouse colorectum undergoing TNBS-induced colitis and draws attention to curvy fibers in the submucosa with potential roles in visceral nociception.NEW & NOTEWORTHY We conducted genetic labeling and optical clearing to visualize extrinsic sensory nerve fibers in whole-mount colorectum, which revealed widespread presence of axons in the submucosal layer. Remarkably, axons in the submucosa were meandering and curvy, in contrast to axons in other layers generally aligned with the basal tissues. Intracolonic TNBS treatment led to pronounced changes of nerve fiber density and curviness, suggesting nerve fiber morphologies as potentially contributing factors to sensory sensitization.
Collapse
Affiliation(s)
- Tiantian Guo
- Department of Biomedical Engineering, University of Connecticut, Mansfield, Connecticut
| | - Shivam Patel
- Department of Physiology and Neurobiology, University of Connecticut, Mansfield, Connecticut
| | - Dhruv Shah
- Department of Molecular and Cell Biology, University of Connecticut, Mansfield, Connecticut
| | - Ling Chi
- Department of Physiology and Neurobiology, University of Connecticut, Mansfield, Connecticut
| | - Sharareh Emadi
- Department of Biomedical Engineering, University of Connecticut, Mansfield, Connecticut
| | - David M Pierce
- Department of Biomedical Engineering, University of Connecticut, Mansfield, Connecticut
- Department of Mechanical Engineering, University of Connecticut, Mansfield, Connecticut
| | - Martin Han
- Department of Biomedical Engineering, University of Connecticut, Mansfield, Connecticut
| | - Pablo R Brumovsky
- Instituto de Investigaciones en Medicina Traslacional, National Scientific and Technical Research Council, Austral University, Buenos Aires, Argentina
| | - Bin Feng
- Department of Biomedical Engineering, University of Connecticut, Mansfield, Connecticut
- Department of Physiology and Neurobiology, University of Connecticut, Mansfield, Connecticut
| |
Collapse
|
10
|
Bayat FK, Polat Budak B, Yiğit EN, Öztürk G, Gülçür HÖ, Güveniş A. Adult mouse dorsal root ganglia neurons form aberrant glutamatergic connections in dissociated cultures. PLoS One 2021; 16:e0246924. [PMID: 33657119 PMCID: PMC7928449 DOI: 10.1371/journal.pone.0246924] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 01/29/2021] [Indexed: 11/18/2022] Open
Abstract
Cultured sensory neurons can exhibit complex activity patterns following stimulation in terms of increased excitability and interconnected responses of multiple neurons. Although these complex activity patterns suggest a network-like configuration, research so far had little interest in synaptic network formation ability of the sensory neurons. To identify interaction profiles of Dorsal Root Ganglia (DRG) neurons and explore their putative connectivity, we developed an in vitro experimental approach. A double transgenic mouse model, expressing genetically encoded calcium indicator (GECI) in their glutamatergic neurons, was produced. Dissociated DRG cultures from adult mice were prepared with a serum-free protocol and no additional growth factors or cytokines were utilized for neuronal sensitization. DRG neurons were grown on microelectrode arrays (MEA) to induce stimulus-evoked activity with a modality-free stimulation strategy. With an almost single-cell level electrical stimulation, spontaneous and evoked activity of GCaMP6s expressing neurons were detected under confocal microscope. Typical responses were analyzed, and correlated calcium events were detected across individual DRG neurons. Next, correlated responses were successfully blocked by glutamatergic receptor antagonists, which indicated functional synaptic coupling. Immunostaining confirmed the presence of synapses mainly in the axonal terminals, axon-soma junctions and axon-axon intersection sites. Concisely, the results presented here illustrate a new type of neuron-to-neuron interaction in cultured DRG neurons conducted through synapses. The developed assay can be a valuable tool to analyze individual and collective responses of the cultured sensory neurons.
Collapse
Affiliation(s)
- F. Kemal Bayat
- Institute of Biomedical Engineering, Bogazici University, İstanbul, Turkey
- Department of Electrical and Electronics Engineering, Faculty of Engineering, Marmara University, İstanbul, Turkey
| | - Betul Polat Budak
- Regenerative and Restorative Medicine Research Center (REMER), Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, İstanbul, Turkey
- Faculty of Engineering and Natural Sciences, Biruni University, İstanbul, Turkey
| | - Esra Nur Yiğit
- Regenerative and Restorative Medicine Research Center (REMER), Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, İstanbul, Turkey
- Institute of Biotechnology, Gebze Technical University, İzmit, Turkey
| | - Gürkan Öztürk
- Regenerative and Restorative Medicine Research Center (REMER), Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, İstanbul, Turkey
| | - Halil Özcan Gülçür
- Institute of Biomedical Engineering, Bogazici University, İstanbul, Turkey
- Faculty of Engineering and Natural Sciences, Biruni University, İstanbul, Turkey
- * E-mail:
| | - Albert Güveniş
- Institute of Biomedical Engineering, Bogazici University, İstanbul, Turkey
| |
Collapse
|
11
|
Ieda N, Minabe S, Ikegami K, Watanabe Y, Sugimoto Y, Sugimoto A, Kawai N, Ishii H, Inoue N, Uenoyama Y, Tsukamura H. GnRH(1-5), a metabolite of gonadotropin-releasing hormone, enhances luteinizing hormone release via activation of kisspeptin neurons in female rats. Endocr J 2020; 67:409-418. [PMID: 31941848 DOI: 10.1507/endocrj.ej19-0444] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Accumulating evidence suggests that kisspeptin neurons in the arcuate nucleus (ARC), which coexpress neurokinin B and dynorphin, are involved in gonadotropin-releasing hormone (GnRH)/luteinizing hormone (LH) pulse generation, while the anteroventral periventricular nucleus (AVPV) kisspeptin neurons are responsible for GnRH/LH surge generation. The present study aims to examine whether GnRH(1-5), a GnRH metabolite, regulates LH release via kisspeptin neurons. GnRH(1-5) was intracerebroventricularly injected to ovariectomized and estrogen-treated Wistar-Imamichi female rats. Immediately after the central GnRH(1-5) administration at 2 nmol, plasma LH concentration increased, resulting in significantly higher levels of the area under the curve and baseline of plasma LH concentrations compared to vehicle-injected controls. On the other hand, in Kiss1 knockout rats, GnRH(1-5) administration failed to affect LH secretion, suggesting that the facilitatory effect of GnRH(1-5) on LH release is mediated by kisspeptin neurons. Double in situ hybridization (ISH) for Kiss1 and Gpr101, a GnRH(1-5) receptor gene, revealed that few Kiss1-expressing cells coexpress Gpr101 in both ARC and AVPV. On the other hand, double ISH for Gpr101 and Slc17a6, a glutamatergic marker gene, revealed that 29.2% of ARC Gpr101-expressing cells coexpress Slc17a6. Further, most of the AVPV and ARC Kiss1-expressing cells coexpress Grin1, a gene encoding a subunit of NMDA receptor. Taken together, these results suggest that the GnRH(1-5)-GPR101 signaling facilitates LH release via indirect activation of kisspeptin neurons and that glutamatergic neurons may mediate the signaling. This provides a new aspect of kisspeptin- and GnRH-neuronal communication with the presence of stimulation from GnRH to kisspeptin neurons in female rats.
Collapse
Affiliation(s)
- Nahoko Ieda
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
| | - Shiori Minabe
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
| | - Kana Ikegami
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
| | - Youki Watanabe
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
| | - Yusuke Sugimoto
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
| | - Arisa Sugimoto
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
| | - Narumi Kawai
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
| | - Hirotaka Ishii
- Department of Anatomy and Neurobiology, Nippon Medical School, Tokyo 113-8602, Japan
| | - Naoko Inoue
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
| | - Yoshihisa Uenoyama
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
| | - Hiroko Tsukamura
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
| |
Collapse
|
12
|
Nitzan N, McKenzie S, Beed P, English DF, Oldani S, Tukker JJ, Buzsáki G, Schmitz D. Propagation of hippocampal ripples to the neocortex by way of a subiculum-retrosplenial pathway. Nat Commun 2020; 11:1947. [PMID: 32327634 PMCID: PMC7181800 DOI: 10.1038/s41467-020-15787-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Accepted: 03/27/2020] [Indexed: 02/07/2023] Open
Abstract
Bouts of high frequency activity known as sharp wave ripples (SPW-Rs) facilitate communication between the hippocampus and neocortex. However, the paths and mechanisms by which SPW-Rs broadcast their content are not well understood. Due to its anatomical positioning, the granular retrosplenial cortex (gRSC) may be a bridge for this hippocampo-cortical dialogue. Using silicon probe recordings in awake, head-fixed mice, we show the existence of SPW-R analogues in gRSC and demonstrate their coupling to hippocampal SPW-Rs. gRSC neurons reliably distinguished different subclasses of hippocampal SPW-Rs according to ensemble activity patterns in CA1. We demonstrate that this coupling is brain state-dependent, and delineate a topographically-organized anatomical pathway via VGlut2-expressing, bursty neurons in the subiculum. Optogenetic stimulation or inhibition of bursty subicular cells induced or reduced responses in superficial gRSC, respectively. These results identify a specific path and underlying mechanisms by which the hippocampus can convey neuronal content to the neocortex during SPW-Rs.
Collapse
Affiliation(s)
- Noam Nitzan
- Charité-Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Neuroscience Research Center, Berlin, Germany
| | - Sam McKenzie
- Neuroscience Institute and Department of Neurology New York University Langone Medical Center, New York, NY, 10016, USA
| | - Prateep Beed
- Charité-Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Neuroscience Research Center, Berlin, Germany
| | - Daniel Fine English
- Neuroscience Institute and Department of Neurology New York University Langone Medical Center, New York, NY, 10016, USA
- School of Neuroscience, College of Science, Virginia Tech, VA, 24061, USA
| | - Silvia Oldani
- Charité-Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Neuroscience Research Center, Berlin, Germany
- Center for Neurodegenerative Diseases (DZNE), Berlin, Germany
| | - John J Tukker
- Charité-Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Neuroscience Research Center, Berlin, Germany
- Center for Neurodegenerative Diseases (DZNE), Berlin, Germany
| | - György Buzsáki
- Neuroscience Institute and Department of Neurology New York University Langone Medical Center, New York, NY, 10016, USA.
- Center for Neural Science, New York University, New York, NY, 10016, USA.
| | - Dietmar Schmitz
- Charité-Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Neuroscience Research Center, Berlin, Germany.
- Center for Neurodegenerative Diseases (DZNE), Berlin, Germany.
- Cluster of Excellence NeuroCure, Berlin, Germany.
- Einstein Center for Neurosciences, Berlin, Germany.
| |
Collapse
|
13
|
Gonzalez D, Tomasek M, Hays S, Sridhar V, Ammanuel S, Chang CW, Pawlowski K, Huber KM, Gibson JR. Audiogenic Seizures in the Fmr1 Knock-Out Mouse Are Induced by Fmr1 Deletion in Subcortical, VGlut2-Expressing Excitatory Neurons and Require Deletion in the Inferior Colliculus. J Neurosci 2019; 39:9852-9863. [PMID: 31666356 PMCID: PMC6891051 DOI: 10.1523/jneurosci.0886-19.2019] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 09/06/2019] [Accepted: 10/16/2019] [Indexed: 02/07/2023] Open
Abstract
Fragile X syndrome (FXS) is the most common form of inherited intellectual disability and the leading monogenetic cause of autism. One symptom of FXS and autism is sensory hypersensitivity (also called sensory over-responsivity). Perhaps related to this, the audiogenic seizure (AGS) is arguably the most robust behavioral phenotype in the FXS mouse model-the Fmr1 knock-out (KO) mouse. Therefore, the AGS may be considered a mouse model of sensory hypersensitivity. Hyperactive circuits are hypothesized to underlie dysfunction in a number of brain regions in patients with FXS and Fmr1 KO mice, and the AGS may be a result of this. But the specific cell types and brain regions underlying AGSs in the Fmr1 KO are unknown. We used conditional deletion or expression of Fmr1 in different cell populations to determine whether Fmr1 deletion in those cells was sufficient or necessary, respectively, for the AGS phenotype in males. Our data indicate that Fmr1 deletion in glutamatergic neurons that express vesicular glutamate transporter 2 (VGlut2) and are located in subcortical brain regions is sufficient and necessary to cause AGSs. Furthermore, the deletion of Fmr1 in glutamatergic neurons of the inferior colliculus is necessary for AGSs. When we demonstrate necessity, we show that Fmr1 expression in either the larger population of VGlut2-expressing glutamatergic neurons or the smaller population of inferior collicular glutamatergic neurons-in an otherwise Fmr1 KO mouse-eliminates AGSs. Therefore, targeting these neuronal populations in FXS and autism may be part of a therapeutic strategy to alleviate sensory hypersensitivity.SIGNIFICANCE STATEMENT Sensory hypersensitivity in fragile X syndrome (FXS) and autism patients significantly interferes with quality of life. Audiogenic seizures (AGSs) are arguably the most robust behavioral phenotype in the FXS mouse model-the Fmr1 knockout-and may be considered a model of sensory hypersensitivity in FXS. We provide the clearest and most precise genetic evidence to date for the cell types and brain regions involved in causing AGSs in the Fmr1 knockout and, more broadly, for any mouse mutant. The expression of Fmr1 in these same cell types in an otherwise Fmr1 knockout eliminates AGSs indicating possible cellular targets for alleviating sensory hypersensitivity in FXS and other forms of autism.
Collapse
Affiliation(s)
| | | | - Seth Hays
- Department of Neuroscience, Dallas, and
| | | | | | | | - Karen Pawlowski
- Department of Otolaryngology and Biomedical Engineering Program, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9035
| | | | | |
Collapse
|
14
|
Fang Q, Chou XL, Peng B, Zhong W, Zhang LI, Tao HW. A Differential Circuit via Retino-Colliculo-Pulvinar Pathway Enhances Feature Selectivity in Visual Cortex through Surround Suppression. Neuron 2019; 105:355-369.e6. [PMID: 31812514 DOI: 10.1016/j.neuron.2019.10.027] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 08/15/2019] [Accepted: 10/17/2019] [Indexed: 01/06/2023]
Abstract
In the mammalian visual system, information from the retina streams into parallel bottom-up pathways. It remains unclear how these pathways interact to contribute to contextual modulation of visual cortical processing. By optogenetic inactivation and activation of mouse lateral posterior nucleus (LP) of thalamus, a homolog of pulvinar, or its projection to primary visual cortex (V1), we found that LP contributes to surround suppression of layer (L) 2/3 responses in V1 by driving L1 inhibitory neurons. This results in subtractive suppression of visual responses and an overall enhancement of orientation, direction, spatial, and size selectivity. Neurons in V1-projecting LP regions receive bottom-up input from the superior colliculus (SC) and respond preferably to non-patterned visual noise. The noise-dependent LP activity allows V1 to "cancel" noise effects and maintain its orientation selectivity under varying noise background. Thus, the retina-SC-LP-V1 pathway forms a differential circuit with the canonical retino-geniculate pathway to achieve context-dependent sharpening of visual representations.
Collapse
Affiliation(s)
- Qi Fang
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA; Graduate Program in Neuroscience, University of Southern California, Los Angeles, CA 90089, USA
| | - Xiao-Lin Chou
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA; Graduate Program in Neuroscience, University of Southern California, Los Angeles, CA 90089, USA
| | - Bo Peng
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA; Graduate Program in Neuroscience, University of Southern California, Los Angeles, CA 90089, USA
| | - Wen Zhong
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Li I Zhang
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA; Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA.
| | - Huizhong Whit Tao
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA; Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA.
| |
Collapse
|
15
|
Xu W, Huang J, Li L, Zhang X, Wang Y, Tong G, Sun Y. Alterations of estradiol-induced histone H3 acetylation in the preoptic area and anteroventral periventricular nucleus of middle-aged female rats. Biochem Biophys Res Commun 2019; 516:894-899. [PMID: 31272713 DOI: 10.1016/j.bbrc.2019.06.145] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 06/26/2019] [Indexed: 02/06/2023]
Abstract
In this study we investigated the characteristics of histone H3 acetylation in the anterior hypothalamus under E2 positive feedback to gain a better understanding of the mechanism underlying reduced GnRH neuron activation and altered gene expression in female reproductive aging. Young and middle-aged female rats were ovariectomized (OVX) and treated with estradiol (E2) or oil. C-Fos expression, the number of GnRH neurons co-localized with c-Fos in the preoptic area (POA), and the number of acetylated histone H3 cells in the POA and anteroventral periventricular nucleus (AVPV) were quantified at the time of the expected GnRH neuron activation. We used real-time PCR to evaluate the expression of Esr1 target genes including Kiss1 and VGluT2 and genes known as Esr1 coregulators in the anterior hypothalamus. Our results show that in the young females, E2 markedly increased histone H3 acetylation in the POA and AVPV, coincident with increased c-Fos and GnRH neuron activation in the POA. In middle-aged females, E2-induced histone H3 acetylation was reduced in the POA but was not significantly altered in the AVPV. This occurred in association with a reduction of c-Fos expression and the number of GnRH cells expressing c-Fos in the POA as well as a down-regulation of Kiss1 and VGluT2 mRNA expression in the anterior hypothalamus of the animals. E2 caused significant decreases in Ncoa2 and Crebbp mRNA expression in the anterior hypothalamus of young, but not middle-aged females. Taken together, these data suggest that alterations of histone H3 acetylation in the POA and AVPV and the inability of Ncoa2 and Crebbp to respond to E2 in the middle-aged anterior hypothalamus partially contribute to the decline of GnRH neuron activation and E2 target gene expression changes that occur in female along with reproductive aging.
Collapse
Affiliation(s)
- Wen Xu
- Hospital & Institute of Obstetrics and Gynecology, Fudan University, Shanghai, 200011, China
| | - Jianqin Huang
- Hospital & Institute of Obstetrics and Gynecology, Fudan University, Shanghai, 200011, China; The Academy of Integrative Medicine of Fudan University, Shanghai, 200011, China
| | - Lisha Li
- Hospital & Institute of Obstetrics and Gynecology, Fudan University, Shanghai, 200011, China
| | - Xinyan Zhang
- Hospital & Institute of Obstetrics and Gynecology, Fudan University, Shanghai, 200011, China
| | - Yan Wang
- Hospital & Institute of Obstetrics and Gynecology, Fudan University, Shanghai, 200011, China
| | - Guoqing Tong
- Reproduction Center, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China.
| | - Yan Sun
- Hospital & Institute of Obstetrics and Gynecology, Fudan University, Shanghai, 200011, China; The Academy of Integrative Medicine of Fudan University, Shanghai, 200011, China; Shanghai Key Laboratory of Female Reproductive Endocrine-related Disease, Shanghai, 200011, China.
| |
Collapse
|
16
|
Assous M, Dautan D, Tepper JM, Mena-Segovia J. Pedunculopontine Glutamatergic Neurons Provide a Novel Source of Feedforward Inhibition in the Striatum by Selectively Targeting Interneurons. J Neurosci 2019; 39:4727-4737. [PMID: 30952811 PMCID: PMC6561696 DOI: 10.1523/jneurosci.2913-18.2019] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 03/01/2019] [Accepted: 03/07/2019] [Indexed: 11/21/2022] Open
Abstract
The main excitatory inputs to the striatum arising from the cortex and the thalamus innervate both striatal spiny projection neurons and interneurons. These glutamatergic inputs to striatal GABAergic interneurons have been suggested to regulate the spike timing of striatal projection neurons via feedforward inhibition. Understanding how different excitatory inputs are integrated within the striatal circuitry and how they regulate striatal output is crucial for understanding basal ganglia function and related behaviors. Here, using VGLUT2 mice from both sexes, we report the existence of a glutamatergic projection from the mesencephalic locomotor region to the striatum that avoids the spiny neurons and selectively innervates interneurons. Specifically, optogenetic activation of glutamatergic axons from the pedunculopontine nucleus induced monosynaptic excitation in most recorded striatal cholinergic interneurons and GABAergic fast-spiking interneurons. Optogenetic stimulation in awake head-fixed mice consistently induced an increase in the firing rate of putative cholinergic interneurons and fast-spiking interneurons. In contrast, this stimulation did not induce excitatory responses in spiny neurons but rather disynaptic inhibitory responses ex vivo and a decrease in their firing rate in vivo, suggesting a feedforward mechanism mediating the inhibition of spiny projection neurons through the selective activation of striatal interneurons. Furthermore, unilateral stimulation of pedunculopontine nucleus glutamatergic axons in the striatum induced ipsilateral head rotations consistent with the inhibition of striatal output neurons. Our results demonstrate the existence of a unique interneuron-specific midbrain glutamatergic input to the striatum that exclusively recruits feedforward inhibition mechanisms.SIGNIFICANCE STATEMENT Glutamatergic inputs to the striatum have been shown to target both striatal projection neurons and interneurons and have been proposed to regulate spike timing of the projection neurons in part through feedforward inhibition. Here, we reveal the existence of a midbrain source of glutamatergic innervation to the striatum, originating in the pedunculopontine nucleus. Remarkably, this novel input selectively targets striatal interneurons, avoiding the projection neurons. Furthermore, we show that this selective innervation of interneurons can regulate the firing of the spiny projection neurons and inhibit the striatal output via feedforward inhibition. Together, our results describe a unique source of excitatory innervation to the striatum which selectively recruits feedforward inhibition of spiny neurons without any accompanying excitation.
Collapse
Affiliation(s)
- Maxime Assous
- Center for Molecular and Behavioral Neuroscience, Rutgers University, Newark, New Jersey 07102
| | - Daniel Dautan
- Center for Molecular and Behavioral Neuroscience, Rutgers University, Newark, New Jersey 07102
| | - James M Tepper
- Center for Molecular and Behavioral Neuroscience, Rutgers University, Newark, New Jersey 07102
| | - Juan Mena-Segovia
- Center for Molecular and Behavioral Neuroscience, Rutgers University, Newark, New Jersey 07102
| |
Collapse
|
17
|
Abstract
The basal forebrain (BF) contains at least three distinct populations of neurons (cholinergic, glutamatergic, and GABA-ergic) across its different regions (medial septum, diagonal band, magnocellular preoptic area, and substantia innominata). Much attention has focused on the BF's ascending projections to cortex, but less is known about descending projections to subcortical regions. Given the neurochemical and anatomical heterogeneity of the BF, we used conditional anterograde tracing to map the patterns of subcortical projections from multiple BF regions and neurochemical cell types using mice that express Cre recombinase only in cholinergic, glutamatergic, or GABAergic neurons. We confirmed that different BF regions innervate distinct subcortical targets, with more subcortical projections arising from neurons in the caudal and lateral BF (substantia innominata and magnocellular preoptic area). Additionally, glutamatergic and GABAergic BF neurons have distinct patterns of descending projections, while cholinergic descending projections are sparse. Considering the intensity of glutamatergic and GABAergic descending projections, the BF likely acts through subcortical targets to promote arousal, motivation, and other behaviors.
Collapse
Affiliation(s)
- Lindsay J Agostinelli
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, 02215, USA
- Department of Neurology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Joel C Geerling
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, 02215, USA
- Department of Neurology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Thomas E Scammell
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, 02215, USA.
| |
Collapse
|
18
|
Naganuma F, Bandaru SS, Absi G, Chee MJ, Vetrivelan R. Melanin-concentrating hormone neurons promote rapid eye movement sleep independent of glutamate release. Brain Struct Funct 2018; 224:99-110. [PMID: 30284033 DOI: 10.1007/s00429-018-1766-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 09/27/2018] [Indexed: 12/20/2022]
Abstract
Neurons containing melanin-concentrating hormone (MCH) in the posterior lateral hypothalamus play an integral role in rapid eye movement sleep (REMs) regulation. As MCH neurons also contain a variety of other neuropeptides [e.g., cocaine- and amphetamine-regulated transcript (CART) and nesfatin-1] and neurotransmitters (e.g., glutamate), the specific neurotransmitter responsible for REMs regulation is not known. We hypothesized that glutamate, the primary fast-acting neurotransmitter in MCH neurons, is necessary for REMs regulation. To test this hypothesis, we deleted vesicular glutamate transporter (Vglut2; necessary for synaptic release of glutamate) specifically from MCH neurons by crossing MCH-Cre mice (expressing Cre recombinase in MCH neurons) with Vglut2flox/flox mice (expressing LoxP-modified alleles of Vglut2), and studied the amounts, architecture and diurnal variation of sleep-wake states during baseline conditions. We then activated the MCH neurons lacking glutamate neurotransmission using chemogenetic methods and tested whether these MCH neurons still promoted REMs. Our results indicate that glutamate in MCH neurons contributes to normal diurnal variability of REMs by regulating the levels of REMs during the dark period, but MCH neurons can promote REMs even in the absence of glutamate.
Collapse
Affiliation(s)
- Fumito Naganuma
- Department of Neurology, Beth Israel Deaconess Medical Center and Division of Sleep Medicine, Harvard Medical School, 3 Blackfan Circle, Center for Life Science # 717, Boston, MA, 02215, USA
- Division of Pharmacology, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, 1-15-1, Fukumuro, Miyagino-ku, Sendai, 983-8536, Japan
| | - Sathyajit S Bandaru
- Department of Neurology, Beth Israel Deaconess Medical Center and Division of Sleep Medicine, Harvard Medical School, 3 Blackfan Circle, Center for Life Science # 717, Boston, MA, 02215, USA
| | - Gianna Absi
- Department of Neurology, Beth Israel Deaconess Medical Center and Division of Sleep Medicine, Harvard Medical School, 3 Blackfan Circle, Center for Life Science # 717, Boston, MA, 02215, USA
| | - Melissa J Chee
- Department of Neuroscience, Carleton University, Ottawa, ON, K1S 5B6, Canada
| | - Ramalingam Vetrivelan
- Department of Neurology, Beth Israel Deaconess Medical Center and Division of Sleep Medicine, Harvard Medical School, 3 Blackfan Circle, Center for Life Science # 717, Boston, MA, 02215, USA.
| |
Collapse
|
19
|
Menegas W, Akiti K, Amo R, Uchida N, Watabe-Uchida M. Dopamine neurons projecting to the posterior striatum reinforce avoidance of threatening stimuli. Nat Neurosci 2018; 21:1421-1430. [PMID: 30177795 PMCID: PMC6160326 DOI: 10.1038/s41593-018-0222-1] [Citation(s) in RCA: 181] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 07/18/2018] [Indexed: 01/07/2023]
Abstract
Midbrain dopamine neurons are well known for their role in reward-based reinforcement learning. We found that the activity of dopamine axons in the posterior tail of the striatum (TS) scaled with the novelty and intensity of external stimuli, but did not encode reward value. We demonstrated that the ablation of TS-projecting dopamine neurons specifically inhibited avoidance of novel or high-intensity stimuli without affecting animals' initial avoidance responses, suggesting a role in reinforcement rather than simply in avoidance itself. Furthermore, we found that animals avoided optogenetic activation of dopamine axons in TS during a choice task and that this stimulation could partially reinstate avoidance of a familiar object. These results suggest that TS-projecting dopamine neurons reinforce avoidance of threatening stimuli. More generally, our results indicate that there are at least two axes of reinforcement learning using dopamine in the striatum: one based on value and one based on external threat.
Collapse
Affiliation(s)
- William Menegas
- Center for Brain Science, Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Korleki Akiti
- Center for Brain Science, Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Ryunosuke Amo
- Center for Brain Science, Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Naoshige Uchida
- Center for Brain Science, Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Mitsuko Watabe-Uchida
- Center for Brain Science, Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA.
| |
Collapse
|
20
|
Qiu J, Rivera HM, Bosch MA, Padilla SL, Stincic TL, Palmiter RD, Kelly MJ, Rønnekleiv OK. Estrogenic-dependent glutamatergic neurotransmission from kisspeptin neurons governs feeding circuits in females. eLife 2018; 7:e35656. [PMID: 30079889 PMCID: PMC6103748 DOI: 10.7554/elife.35656] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Accepted: 07/24/2018] [Indexed: 11/13/2022] Open
Abstract
The neuropeptides tachykinin2 (Tac2) and kisspeptin (Kiss1) in hypothalamic arcuate nucleus Kiss1 (Kiss1ARH) neurons are essential for pulsatile release of GnRH and reproduction. Since 17β-estradiol (E2) decreases Kiss1 and Tac2 mRNA expression in Kiss1ARH neurons, the role of Kiss1ARH neurons during E2-driven anorexigenic states and their coordination of POMC and NPY/AgRP feeding circuits have been largely ignored. Presently, we show that E2 augmented the excitability of Kiss1ARH neurons by amplifying Cacna1g, Hcn1 and Hcn2 mRNA expression and T-type calcium and h-currents. E2 increased Slc17a6 mRNA expression and glutamatergic synaptic input to arcuate neurons, which excited POMC and inhibited NPY/AgRP neurons via metabotropic receptors. Deleting Slc17a6 in Kiss1 neurons eliminated glutamate release and led to conditioned place preference for sucrose in E2-treated KO female mice. Therefore, the E2-driven increase in Kiss1 neuronal excitability and glutamate neurotransmission may play a key role in governing the motivational drive for palatable food in females.
Collapse
Affiliation(s)
- Jian Qiu
- Department of Physiology and PharmacologyOregon Health and Science UniversityPortlandUnited States
| | - Heidi M Rivera
- Department of Physiology and PharmacologyOregon Health and Science UniversityPortlandUnited States
| | - Martha A Bosch
- Department of Physiology and PharmacologyOregon Health and Science UniversityPortlandUnited States
| | - Stephanie L Padilla
- Department of BiochemistryHoward Hughes Medical Institute, University of WashingtonSeattleUnited States
| | - Todd L Stincic
- Department of Physiology and PharmacologyOregon Health and Science UniversityPortlandUnited States
| | - Richard D Palmiter
- Department of BiochemistryHoward Hughes Medical Institute, University of WashingtonSeattleUnited States
| | - Martin J Kelly
- Department of Physiology and PharmacologyOregon Health and Science UniversityPortlandUnited States
- Division of NeuroscienceOregon National Primate Research Center, Oregon Health and Science UniversityBeavertonUnited States
| | - Oline K Rønnekleiv
- Department of Physiology and PharmacologyOregon Health and Science UniversityPortlandUnited States
- Division of NeuroscienceOregon National Primate Research Center, Oregon Health and Science UniversityBeavertonUnited States
| |
Collapse
|
21
|
Adams JM, Pei H, Sandoval DA, Seeley RJ, Chang RB, Liberles SD, Olson DP. Liraglutide Modulates Appetite and Body Weight Through Glucagon-Like Peptide 1 Receptor-Expressing Glutamatergic Neurons. Diabetes 2018; 67:1538-1548. [PMID: 29776968 PMCID: PMC6054439 DOI: 10.2337/db17-1385] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 05/06/2018] [Indexed: 12/18/2022]
Abstract
Glucagon-like peptide 1 receptor (GLP-1R) agonists are U.S. Food and Drug Administration-approved weight loss drugs. Despite their widespread use, the sites of action through which GLP-1R agonists (GLP1RAs) affect appetite and body weight are still not fully understood. We determined whether GLP-1Rs in either GABAergic or glutamatergic neurons are necessary for the short- and long-term effects of the GLP1RA liraglutide on food intake, visceral illness, body weight, and neural network activation. We found that mice lacking GLP-1Rs in vGAT-expressing GABAergic neurons responded identically to controls in all parameters measured, whereas deletion of GLP-1Rs in vGlut2-expressing glutamatergic neurons eliminated liraglutide-induced weight loss and visceral illness and severely attenuated its effects on feeding. Concomitantly, deletion of GLP-1Rs from glutamatergic neurons completely abolished the neural network activation observed after liraglutide administration. We conclude that liraglutide activates a dispersed but discrete neural network to mediate its physiological effects and that these effects require GLP-1R expression on glutamatergic but not GABAergic neurons.
Collapse
Affiliation(s)
- Jessica M Adams
- Department of Pediatrics, University of Michigan, Ann Arbor, MI
| | - Hongjuan Pei
- Department of Pediatrics, University of Michigan, Ann Arbor, MI
| | | | - Randy J Seeley
- Department of Surgery, University of Michigan, Ann Arbor, MI
| | - Rui B Chang
- Department of Cell Biology, Harvard Medical School, Boston, MA
| | | | - David P Olson
- Department of Pediatrics, University of Michigan, Ann Arbor, MI
| |
Collapse
|
22
|
Abstract
The transport of glutamate into synaptic vesicles exhibits an unusual form of regulation by Cl- as well as an associated Cl- conductance. To distinguish direct effects of Cl- on the transporter from indirect effects via the driving force Δψ, we used whole endosome recording and report the first currents due to glutamate flux by the vesicular glutamate transporters (VGLUTs). Chloride allosterically activates the VGLUTs from both sides of the membrane, and we find that neutralization of an arginine in transmembrane domain four suffices for the lumenal activation. The dose dependence suggests that Cl- permeates through a channel and glutamate through a transporter. Competition between the anions nonetheless indicates that they use a similar permeation pathway. By controlling both ionic gradients and Δψ, endosome recording isolates different steps in the process of synaptic vesicle filling, suggesting distinct roles for Cl- in both allosteric activation and permeation.
Collapse
Affiliation(s)
- Roger Chang
- Department of PhysiologyUCSF School of MedicineSan FranciscoUnited States
- Department of NeurologyUCSF School of MedicineSan FranciscoUnited States
- Graduate Program in Biomedical SciencesUCSF School of MedicineSan FranciscoUnited States
| | - Jacob Eriksen
- Department of PhysiologyUCSF School of MedicineSan FranciscoUnited States
- Department of NeurologyUCSF School of MedicineSan FranciscoUnited States
| | - Robert H Edwards
- Department of PhysiologyUCSF School of MedicineSan FranciscoUnited States
- Department of NeurologyUCSF School of MedicineSan FranciscoUnited States
- Graduate Program in Biomedical SciencesUCSF School of MedicineSan FranciscoUnited States
- Kavli Institute for Fundamental NeuroscienceUCSF School of MedicineSan FranciscoUnited States
- Weill Institute for NeurosciencesUCSF School of MedicineSan FranciscoUnited States
| |
Collapse
|
23
|
Soteros BM, Cong Q, Palmer CR, Sia GM. Sociability and synapse subtype-specific defects in mice lacking SRPX2, a language-associated gene. PLoS One 2018; 13:e0199399. [PMID: 29920554 PMCID: PMC6007900 DOI: 10.1371/journal.pone.0199399] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 06/06/2018] [Indexed: 01/05/2023] Open
Abstract
The FoxP2 transcription factor and its target genes have been implicated in developmental brain diseases with a prominent language component, such as developmental verbal dyspraxia and specific language impairment. How FoxP2 affects neural circuitry development remains poorly understood. The sushi domain protein SRPX2 is a target of FoxP2, and mutations in SRPX2 are associated with language defects in humans. We have previously shown that SRPX2 is a synaptogenic protein that increases excitatory synapse density. Here we provide the first characterization of mice lacking the SRPX2 gene, and show that these mice exhibit defects in both neural circuitry and communication and social behaviors. Specifically, we show that mice lacking SRPX2 show a specific reduction in excitatory VGlut2 synapses in the cerebral cortex, while VGlut1 and inhibitory synapses were largely unaffected. SRPX2 KO mice also exhibit an abnormal ultrasonic vocalization ontogenetic profile in neonatal pups, and reduced preference for social novelty. These data demonstrate a functional role for SRPX2 during brain development, and further implicate FoxP2 and its targets in regulating the development of vocalization and social circuits.
Collapse
Affiliation(s)
- Breeanne M. Soteros
- Department of Pharmacology, The University of Texas Health Science Center at San Antonio, San Antonio, TX, United States of America
| | - Qifei Cong
- Department of Pharmacology, The University of Texas Health Science Center at San Antonio, San Antonio, TX, United States of America
| | - Christian R. Palmer
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, United States of America
| | - Gek-Ming Sia
- Department of Pharmacology, The University of Texas Health Science Center at San Antonio, San Antonio, TX, United States of America
- * E-mail:
| |
Collapse
|
24
|
Tooley J, Marconi L, Alipio JB, Matikainen-Ankney B, Georgiou P, Kravitz AV, Creed MC. Glutamatergic Ventral Pallidal Neurons Modulate Activity of the Habenula-Tegmental Circuitry and Constrain Reward Seeking. Biol Psychiatry 2018; 83:1012-1023. [PMID: 29452828 PMCID: PMC5972062 DOI: 10.1016/j.biopsych.2018.01.003] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 01/02/2018] [Accepted: 01/04/2018] [Indexed: 12/29/2022]
Abstract
BACKGROUND The ability to appropriately integrate and respond to rewarding and aversive stimuli is essential for survival. The ventral pallidum (VP) plays a critical role in processing both rewarding and aversive stimuli. However, the VP is a heterogeneous structure, and how VP subpopulations integrate into larger reward networks to ultimately modulate these behaviors is not known. We identify a noncanonical population of glutamatergic VP neurons that play a unique role in responding to aversive stimuli and constraining inappropriate reward seeking. METHODS Using neurochemical, genetic, and electrophysiological approaches, we characterized glutamatergic VP neurons (n = 4-8 mice/group). We performed patch clamp and in vivo electrophysiology recordings in the lateral habenula, rostromedial tegmental nucleus, and ventral tegmental area to determine the effect of glutamatergic VP neuron activation in these target regions (n = 6-10 mice/group). Finally, we selectively optogenetically stimulated glutamatergic VP neurons in a real-time place preference task and ablated these neurons using a virally expressed caspase to determine their necessity for reward seeking. RESULTS Glutamatergic VP neurons exhibit little overlap with cholinergic or gamma-aminobutyric acidergic markers, the canonical VP subtypes, and exhibit distinct membrane properties. Glutamatergic VP neurons innervate and increase firing activity of the lateral habenula, rostromedial tegmental nucleus, and gamma-aminobutyric acidergic ventral tegmental area neurons. While nonselective optogenetic stimulation of the VP induced a robust place preference, selective activation of glutamatergic VP neurons induced a place avoidance. Viral ablation of glutamatergic VP neurons increased reward responding and abolished taste aversion to sucrose. CONCLUSIONS Glutamatergic VP neurons constitute a noncanonical subpopulation of VP neurons. These glutamatergic VP neurons increase activity of the lateral habenula, rostromedial tegmental nucleus, and gamma-aminobutyric acidergic ventral tegmental area neurons and adaptively constrain reward seeking.
Collapse
Affiliation(s)
- Jessica Tooley
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Lauren Marconi
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Jason Bondoc Alipio
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Bridget Matikainen-Ankney
- Eating and Addiction Section, National Institute of Digestive and Diabetes and Kidney Diseases, Bethesda, Maryland
| | - Polymnia Georgiou
- Department of Psychiatry, University of Maryland School of Medicine, Baltimore, Maryland
| | - Alexxai V Kravitz
- Eating and Addiction Section, National Institute of Digestive and Diabetes and Kidney Diseases, Bethesda, Maryland
| | - Meaghan C Creed
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland.
| |
Collapse
|
25
|
Zhang ZL, Yu G, Liang XN, Su RB, Gong ZH. Selective downregulation of vesicular glutamate transporter2 in ventral posterolateral nucleus of thalamus attenuates neuropathic mechanical allodynia in mice. Eur J Pharmacol 2018; 828:103-109. [PMID: 29605418 DOI: 10.1016/j.ejphar.2018.03.040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 03/28/2018] [Accepted: 03/28/2018] [Indexed: 01/08/2023]
Abstract
Vesicular glutamate transporters (VGLUTs) transport glutamate into synaptic vesicles prior to exocytotic release. The expression pattern of VGLUT2 and studies of genetically modified mice have revealed that VGLUT2 contributes to neuropathic pain. We previously showed that VGLUT2 is upregulated in supraspinal regions including the thalamus in mice following spared nerve injury (SNI), and blocking VGLUTs using the VGLUT inhibitor CSB6B attenuated mechanical allodynia. To further evaluate the role of VGLUT2 in neuropathic pain, in this study, we developed a lentiviral vector expressing small hairpin RNAs (shRNAs) against mouse VGLUT2, which was injected into the ventral posterolateral (VPL) nucleus of the thalamus in the presence or absence of SNI. The administration of VGLUT2 shRNAs result in downregulation of VGLUT2 mRNA and protein expression, and decreased extracellular glutamate release in primary cultured neurons. We also showed that VGLUT2 shRNAs attenuated SNI-induced mechanical allodynia, in accordance with knockdown of VGLUT2 in the VPL nucleus in mice. Accordingly, our study supports the essential role of supraspinal VGLUT2 in neuropathic pain in adult mice and, thereby, validates VGLUT2 as a potential target for neuropathic pain therapy.
Collapse
Affiliation(s)
- Zhi-Ling Zhang
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, 27 Taiping Road, Beijing 100850, China
| | - Gang Yu
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, 27 Taiping Road, Beijing 100850, China.
| | - Xiao-Nan Liang
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, 27 Taiping Road, Beijing 100850, China
| | - Rui-Bin Su
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, 27 Taiping Road, Beijing 100850, China.
| | - Ze-Hui Gong
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, 27 Taiping Road, Beijing 100850, China
| |
Collapse
|
26
|
Ebisu H, Iwai-Takekoshi L, Fujita-Jimbo E, Momoi T, Kawasaki H. Foxp2 Regulates Identities and Projection Patterns of Thalamic Nuclei During Development. Cereb Cortex 2017; 27:3648-3659. [PMID: 27384060 DOI: 10.1093/cercor/bhw187] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The molecular mechanisms underlying the formation of the thalamus during development have been investigated intensively. Although transcription factors distinguishing the thalamic primordium from adjacent brain structures have been uncovered, those involved in patterning inside the thalamus are largely unclear. Here, we show that Foxp2, a member of the forkhead transcription factor family, regulates thalamic patterning during development. We found a graded expression pattern of Foxp2 in the thalamic primordium of the mouse embryo. The expression levels of Foxp2 were high in the posterior region and low in the anterior region of the thalamic primordium. In Foxp2 (R552H) knockin mice, which have a missense loss-of-function mutation in the forkhead domain of Foxp2, thalamic nuclei of the posterior region of the thalamus were shrunken, while those of the intermediate region were expanded. Consistently, Foxp2 (R552H) knockin mice showed changes in thalamocortical projection patterns. Our results uncovered important roles of Foxp2 in thalamic patterning and thalamocortical projections during development.
Collapse
Affiliation(s)
- Haruka Ebisu
- Department of Medical Neuroscience, Graduate School of Medical Sciences, Kanazawa University, Ishikawa 920-8640, Japan
- Brain/Liver Interface Medicine Research Center, Kanazawa University, Ishikawa 920-8640, Japan
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
- Department of Molecular and Systems Neurobiology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Lena Iwai-Takekoshi
- Department of Molecular and Systems Neurobiology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Eriko Fujita-Jimbo
- Department of Pediatrics, Jichi Medical University, Tochigi 329-0498, Japan
| | - Takashi Momoi
- Department of Pathophysiology, Tokyo Medical University, Tokyo 160-8402, Japan
| | - Hiroshi Kawasaki
- Department of Medical Neuroscience, Graduate School of Medical Sciences, Kanazawa University, Ishikawa 920-8640, Japan
- Brain/Liver Interface Medicine Research Center, Kanazawa University, Ishikawa 920-8640, Japan
- Department of Molecular and Systems Neurobiology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| |
Collapse
|
27
|
Yang C, McKenna JT, Brown RE. Intrinsic membrane properties and cholinergic modulation of mouse basal forebrain glutamatergic neurons in vitro. Neuroscience 2017; 352:249-261. [PMID: 28411158 PMCID: PMC5505269 DOI: 10.1016/j.neuroscience.2017.04.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 03/20/2017] [Accepted: 04/03/2017] [Indexed: 02/02/2023]
Abstract
The basal forebrain (BF) controls sleep-wake cycles, attention and reward processing. Compared to cholinergic and GABAergic neurons, BF glutamatergic neurons are less well understood, due to difficulties in identification. Here, we use vesicular glutamate transporter 2 (vGluT2)-tdTomato mice, expressing a red fluorescent protein (tdTomato) in the major group of BF glutamatergic neurons (vGluT2+) to characterize their intrinsic electrical properties and cholinergic modulation. Whole-cell, patch-clamp recordings were made from vGluT2+ neurons in coronal BF slices. Most BF vGluT2+ neurons were small/medium sized (<20µm), exhibited moderately sized H-currents and had a maximal firing frequency of ∼50Hz. However, vGluT2+ neurons in dorsal BF (ventral pallidum) had larger H-currents and a higher maximal firing rate (83Hz). A subset of BF vGluT2+ neurons exhibited burst/cluster firing. Most vGluT2+ neurons had low-threshold calcium spikes/currents. vGluT2+ neurons located in ventromedial regions of BF (in or adjacent to the horizontal limb of the diagonal band) were strongly hyperpolarized by the cholinergic agonist, carbachol, a finding apparently in conflict with their increased discharge during wakefulness/REM sleep and hypothesized role in wake-promotion. In contrast, most vGluT2+ neurons located in lateral BF (magnocellular preoptic area) or dorsal BF did not respond to carbachol. Our results suggest that BF glutamatergic neurons are heterogeneous and have morphological, electrical and pharmacological properties which distinguish them from BF cholinergic and GABAergic neurons. A subset of vGluT2+ neurons, possibly those neurons which project to reward-related areas such as the habenula, are hyperpolarized by cholinergic inputs, which may cause phasic inhibition during reward-related events.
Collapse
Affiliation(s)
- Chun Yang
- VA Boston Healthcare System and Harvard Medical School, Department of Psychiatry, 1400 VFW Parkway, West Roxbury, MA 02132, USA.
| | - James T McKenna
- VA Boston Healthcare System and Harvard Medical School, Department of Psychiatry, 1400 VFW Parkway, West Roxbury, MA 02132, USA.
| | - Ritchie E Brown
- VA Boston Healthcare System and Harvard Medical School, Department of Psychiatry, 1400 VFW Parkway, West Roxbury, MA 02132, USA; VA Boston Healthcare System and Harvard Medical School, Department of Psychiatry, Research 116A, 940 Belmont Street, Brockton, MA 02301, USA.
| |
Collapse
|
28
|
Schweizer N, Viereckel T, Smith-Anttila CJ, Nordenankar K, Arvidsson E, Mahmoudi S, Zampera A, Wärner Jonsson H, Bergquist J, Lévesque D, Konradsson-Geuken Å, Andersson M, Dumas S, Wallén-Mackenzie Å. Reduced Vglut2/Slc17a6 Gene Expression Levels throughout the Mouse Subthalamic Nucleus Cause Cell Loss and Structural Disorganization Followed by Increased Motor Activity and Decreased Sugar Consumption. eNeuro 2016; 3:ENEURO.0264-16.2016. [PMID: 27699212 PMCID: PMC5041164 DOI: 10.1523/eneuro.0264-16.2016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 09/08/2016] [Indexed: 12/24/2022] Open
Abstract
The subthalamic nucleus (STN) plays a central role in motor, cognitive, and affective behavior. Deep brain stimulation (DBS) of the STN is the most common surgical intervention for advanced Parkinson's disease (PD), and STN has lately gained attention as target for DBS in neuropsychiatric disorders, including obsessive compulsive disorder, eating disorders, and addiction. Animal studies using STN-DBS, lesioning, or inactivation of STN neurons have been used extensively alongside clinical studies to unravel the structural organization, circuitry, and function of the STN. Recent studies in rodent STN models have exposed different roles for STN neurons in reward-related functions. We have previously shown that the majority of STN neurons express the vesicular glutamate transporter 2 gene (Vglut2/Slc17a6) and that reduction of Vglut2 mRNA levels within the STN of mice [conditional knockout (cKO)] causes reduced postsynaptic activity and behavioral hyperlocomotion. The cKO mice showed less interest in fatty rewards, which motivated analysis of reward-response. The current results demonstrate decreased sugar consumption and strong rearing behavior, whereas biochemical analyses show altered dopaminergic and peptidergic activity in the striatum. The behavioral alterations were in fact correlated with opposite effects in the dorsal versus the ventral striatum. Significant cell loss and disorganization of the STN structure was identified, which likely accounts for the observed alterations. Rare genetic variants of the human VGLUT2 gene exist, and this study shows that reduced Vglut2/Slc17a6 gene expression levels exclusively within the STN of mice is sufficient to cause strong modifications in both the STN and the mesostriatal dopamine system.
Collapse
Affiliation(s)
- Nadine Schweizer
- Department of Organismal Biology, Uppsala University, SE-752 36 Uppsala, Sweden
| | - Thomas Viereckel
- Department of Organismal Biology, Uppsala University, SE-752 36 Uppsala, Sweden
- Department of Neuroscience, Uppsala University, SE-751 24 Uppsala, Sweden
| | | | - Karin Nordenankar
- Department of Neuroscience, Uppsala University, SE-751 24 Uppsala, Sweden
| | - Emma Arvidsson
- Department of Organismal Biology, Uppsala University, SE-752 36 Uppsala, Sweden
| | - Souha Mahmoudi
- Faculty of Pharmacy, Université de Montréal, Montréal, QC H3T 1J4, Canada
| | | | - Hanna Wärner Jonsson
- Department of Pharmaceutical Biosciences, Uppsala University, SE-751 24 Uppsala, Sweden
| | - Jonas Bergquist
- Department of Chemistry, BMC - Analytical Chemistry and Neurochemistry, Uppsala University, SE-751 24 Uppsala, Sweden
| | - Daniel Lévesque
- Faculty of Pharmacy, Université de Montréal, Montréal, QC H3T 1J4, Canada
| | | | - Malin Andersson
- Department of Pharmaceutical Biosciences, Uppsala University, SE-751 24 Uppsala, Sweden
| | | | | |
Collapse
|
29
|
Billwiller F, Renouard L, Clement O, Fort P, Luppi PH. Differential origin of the activation of dorsal and ventral dentate gyrus granule cells during paradoxical (REM) sleep in the rat. Brain Struct Funct 2016; 222:1495-1507. [PMID: 27539452 DOI: 10.1007/s00429-016-1289-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 08/11/2016] [Indexed: 11/28/2022]
Abstract
We recently demonstrated that granule cells located in the dorsal dentate gyrus (dDG) are activated by neurons located in the lateral supramammillary nucleus (SumL) during paradoxical sleep (PS) hypersomnia. To determine whether these neurons are glutamatergic and/or GABAergic, we combined FOS immunostaining with in situ hybridization of vesicular glutamate transporter 2 (vGLUT2, a marker of glutamatergic neurons) or that of the vesicular GABA transporter (vGAT, a marker of GABAergic neurons) mRNA in rats displaying PS hypersomnia (PSR). We found that 84 and 76 % of the FOS+ SumL neurons in PSR rats expressed vGLUT2 and vGAT mRNA, respectively. Then, we examined vGLUT2 and FOS immunostaining in the dorsal and ventral DG of PSR rats with a neurochemical lesion of the Sum. In PSR-lesioned animals but not in sham animals, nearly all vGLUT2+ fibers and FOS+ neurons disappeared in the dDG, but not in the ventral DG (vDG). To identify the pathway (s) responsible (s) for the activation of the vDG during PS hypersomnia, we combined Fluorogold (FG) injection in the vDG of PSR rats with FOS staining. We found a large number of neurons FOS-FG+, specifically in the medial entorhinal cortex (ENTm). Altogether, our results suggest that SumL neurons with a unique dual glutamatergic and GABAergic phenotype are responsible for the activation of the dDG during PS hypersomnia, while vDG granule neurons are activated by ENTm cortical neurons. These results suggest differential mechanisms and functions for the activation of the dDG and the vDG granule cells during PS.
Collapse
Affiliation(s)
- Francesca Billwiller
- UMR 5292 CNRS/U1028 INSERM, Faculté de Médecine RTH Laennec, Centre de Recherche en Neurosciences de Lyon (CRNL), SLEEP Team, Université Claude Bernard Lyon I, 7 Rue Guillaume Paradin, 69372, Lyon Cedex 08, France
| | - Leslie Renouard
- UMR 5292 CNRS/U1028 INSERM, Faculté de Médecine RTH Laennec, Centre de Recherche en Neurosciences de Lyon (CRNL), SLEEP Team, Université Claude Bernard Lyon I, 7 Rue Guillaume Paradin, 69372, Lyon Cedex 08, France
| | - Olivier Clement
- UMR 5292 CNRS/U1028 INSERM, Faculté de Médecine RTH Laennec, Centre de Recherche en Neurosciences de Lyon (CRNL), SLEEP Team, Université Claude Bernard Lyon I, 7 Rue Guillaume Paradin, 69372, Lyon Cedex 08, France
| | - Patrice Fort
- UMR 5292 CNRS/U1028 INSERM, Faculté de Médecine RTH Laennec, Centre de Recherche en Neurosciences de Lyon (CRNL), SLEEP Team, Université Claude Bernard Lyon I, 7 Rue Guillaume Paradin, 69372, Lyon Cedex 08, France
| | - Pierre-Hervé Luppi
- UMR 5292 CNRS/U1028 INSERM, Faculté de Médecine RTH Laennec, Centre de Recherche en Neurosciences de Lyon (CRNL), SLEEP Team, Université Claude Bernard Lyon I, 7 Rue Guillaume Paradin, 69372, Lyon Cedex 08, France.
| |
Collapse
|
30
|
Etxeberria A, Hokanson KC, Dao DQ, Mayoral SR, Mei F, Redmond SA, Ullian EM, Chan JR. Dynamic Modulation of Myelination in Response to Visual Stimuli Alters Optic Nerve Conduction Velocity. J Neurosci 2016; 36:6937-48. [PMID: 27358452 PMCID: PMC4926240 DOI: 10.1523/jneurosci.0908-16.2016] [Citation(s) in RCA: 136] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 05/05/2016] [Accepted: 05/20/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Myelin controls the time required for an action potential to travel from the neuronal soma to the axon terminal, defining the temporal manner in which information is processed within the CNS. The presence of myelin, the internodal length, and the thickness of the myelin sheath are powerful structural factors that control the velocity and fidelity of action potential transmission. Emerging evidence indicates that myelination is sensitive to environmental experience and neuronal activity. Activity-dependent modulation of myelination can dynamically alter action potential conduction properties but direct functional in vivo evidence and characterization of the underlying myelin changes is lacking. We demonstrate that in mice long-term monocular deprivation increases oligodendrogenesis in the retinogeniculate pathway but shortens myelin internode lengths without affecting other structural properties of myelinated fibers. We also demonstrate that genetically attenuating synaptic glutamate neurotransmission from retinal ganglion cells phenocopies the changes observed after monocular deprivation, suggesting that glutamate may constitute a signal for myelin length regulation. Importantly, we demonstrate that visual deprivation and shortened internodes are associated with a significant reduction in nerve conduction velocity in the optic nerve. Our results reveal the importance of sensory input in the building of myelinated fibers and suggest that this activity-dependent alteration of myelination is important for modifying the conductive properties of brain circuits in response to environmental experience. SIGNIFICANCE STATEMENT Oligodendrocyte precursor cells differentiate into mature oligodendrocytes and are capable of ensheathing axons with myelin without molecular cues from neurons. However, this default myelination process can be modulated by changes in neuronal activity. Here, we show, for the first time, that experience-dependent activity modifies the length of myelin internodes along axons altering action potential conduction velocity. Such a mechanism would allow for variations in conduction velocities that provide a degree of plasticity in accordance to environmental needs. It will be important in future work to investigate how these changes in myelination and conduction velocity contribute to signal integration in postsynaptic neurons and circuit function.
Collapse
Affiliation(s)
- Ainhoa Etxeberria
- Department of Neurology, University of California, San Francisco, California 94158
| | - Kenton C Hokanson
- Department of Ophthalmology, University of California, San Francisco, California 94143, and Program in Neuroscience, University of California, San Francisco, California 94158
| | - Dang Q Dao
- Department of Ophthalmology, University of California, San Francisco, California 94143, and
| | - Sonia R Mayoral
- Department of Neurology, University of California, San Francisco, California 94158
| | - Feng Mei
- Department of Neurology, University of California, San Francisco, California 94158
| | - Stephanie A Redmond
- Department of Neurology, University of California, San Francisco, California 94158, Program in Neuroscience, University of California, San Francisco, California 94158
| | - Erik M Ullian
- Department of Ophthalmology, University of California, San Francisco, California 94143, and Program in Neuroscience, University of California, San Francisco, California 94158
| | - Jonah R Chan
- Department of Neurology, University of California, San Francisco, California 94158, Program in Neuroscience, University of California, San Francisco, California 94158
| |
Collapse
|
31
|
Xu Y, Chang JT, Myers MG, Xu Y, Tong Q. Euglycemia Restoration by Central Leptin in Type 1 Diabetes Requires STAT3 Signaling but Not Fast-Acting Neurotransmitter Release. Diabetes 2016; 65:1040-9. [PMID: 26822087 PMCID: PMC4806656 DOI: 10.2337/db15-1160] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 01/13/2016] [Indexed: 12/21/2022]
Abstract
Central leptin action is sufficient to restore euglycemia in insulinopenic type 1 diabetes (T1D); however, the underlying mechanism remains poorly understood. To examine the role of intracellular signal transducer and activator of transcription 3 (STAT3) pathways, we used LepRs/s mice with disrupted leptin-phosphorylated STAT3 signaling to test the effect of central leptin on euglycemia restoration. These mice developed streptozocin-induced T1D, which was surprisingly not associated with hyperglucagonemia, a typical manifestation in T1D. Further, leptin action on euglycemia restoration was abrogated in these mice, which was associated with refractory hypercorticosteronemia. To examine the role of fast-acting neurotransmitters glutamate and γ-aminobutyric acid (GABA), two major neurotransmitters in the brain, from leptin receptor (LepR) neurons, we used mice with disrupted release of glutamate, GABA, or both from LepR neurons. Surprisingly, all mice responded normally to leptin-mediated euglycemia restoration, which was associated with expected correction from hyperglucagonemia and hyperphagia. In contrast, mice with loss of glutamate and GABA appeared to develop an additive obesity effect over those with loss of single neurotransmitter release. Thus, our study reveals that STAT3 signaling, but not fast-acting neurotransmitter release, is required for leptin action on euglycemia restoration and that hyperglucagonemia is not required for T1D.
Collapse
Affiliation(s)
- Yuanzhong Xu
- Brown Foundation Institute of Molecular Medicine for the Prevention of Human Diseases of McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX
| | - Jeffrey T Chang
- Brown Foundation Institute of Molecular Medicine for the Prevention of Human Diseases of McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX Department of Integrative Biology and Pharmacology of McGovern Medical School and School of Biomedical Informatics, The University of Texas Health Science Center at Houston, Houston, TX
| | - Martin G Myers
- Departments of Internal Medicine and Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI
| | - Yong Xu
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Qingchun Tong
- Brown Foundation Institute of Molecular Medicine for the Prevention of Human Diseases of McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX
| |
Collapse
|
32
|
Parker PRL, Lalive AL, Kreitzer AC. Pathway-Specific Remodeling of Thalamostriatal Synapses in Parkinsonian Mice. Neuron 2016; 89:734-40. [PMID: 26833136 DOI: 10.1016/j.neuron.2015.12.038] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 10/28/2015] [Accepted: 12/15/2015] [Indexed: 11/17/2022]
Abstract
Movement suppression in Parkinson's disease (PD) is thought to arise from increased efficacy of the indirect pathway basal ganglia circuit, relative to the direct pathway. However, the underlying pathophysiological mechanisms remain elusive. To examine whether changes in the strength of synaptic inputs to these circuits contribute to this imbalance, we obtained paired whole-cell recordings from striatal direct- and indirect-pathway medium spiny neurons (dMSNs and iMSNs) and optically stimulated inputs from sensorimotor cortex or intralaminar thalamus in brain slices from control and dopamine-depleted mice. We found that dopamine depletion selectively decreased synaptic strength at thalamic inputs to dMSNs, suggesting that thalamus drives asymmetric activation of basal ganglia circuitry underlying parkinsonian motor impairments. Consistent with this hypothesis, in vivo chemogenetic and optogenetic inhibition of thalamostriatal terminals reversed motor deficits in dopamine-depleted mice. These results implicate thalamostriatal projections in the pathophysiology of PD and support interventions targeting thalamus as a potential therapeutic strategy.
Collapse
Affiliation(s)
- Philip R L Parker
- Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA 94143, USA; Gladstone Institutes, San Francisco, CA 94158, USA
| | | | - Anatol C Kreitzer
- Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA 94143, USA; Gladstone Institutes, San Francisco, CA 94158, USA; Departments of Physiology and Neurology, University of California San Francisco, CA 94158, USA.
| |
Collapse
|
33
|
Korotkov AA, Glazova MV, Nikitina LS, Dorofeeva NA, Kirillova OD, Chernigovskaya EV. [MOLECULAR MECHANISMS OF ERK1/2 KINASES REGULATION IN THE GLUTAMATE- AND GABA-ERGIC NEURONS DURING SEIZURE EXPRESSION IN KRUSHINSKY-MOLODKINA RATS]. Ross Fiziol Zh Im I M Sechenova 2015; 101:1135-1149. [PMID: 26827493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The aim of the present study was to analyze a role of the ERK1/2 signaling pathway in the regulation of excitation and inhibitory neurons in the hippocampus and the temporal cortex of Krushinsky-Molodkina rats during seizure development finalizing with ataxia. Analysis was done by Western bloting as well as by immunohistochemistry. The results demonstrated significant up-regulation of ERK1/2 activity in the hippocampus in several seconds after sound stimulation. At the same time increased ERK1/2 activity was correlated with enhanced level of SNARE protein SNAP-25 and activation of synapsin I, the proteins which regulate exocytosis machinery. Decreased level of VGLUT2 associated with activation of ERK1/2 and exocytosis proteins supposed activation of glutamate release in the hippocampus, while in the temporal cortex diminished activity of ERK1/2 and synapsin I associated with VGLUT2 up-regulation assumed inhibition of glutamatergic transmission. Our data let us supposed that decreasing of glutamate release in th& temporal cortex could be a trigger for the inhibition of hippocampal glutamatergic system and the beginning of further ataxia stage. Our data demonstrated correlation between expression and activity of exocytosis proteins and ERK1/2 mainly in the glutamategic neurons of the hippocampus and the temporal cortex that let us proposed significant role of ERK1/2 kinases as a positive regulator of glutamate release and as a result initiation of seizure expression.
Collapse
|
34
|
Yin W, Sun Z, Mendenhall JM, Walker DM, Riha PD, Bezner KS, Gore AC. Expression of Vesicular Glutamate Transporter 2 (vGluT2) on Large Dense-Core Vesicles within GnRH Neuroterminals of Aging Female Rats. PLoS One 2015; 10:e0129633. [PMID: 26053743 PMCID: PMC4459826 DOI: 10.1371/journal.pone.0129633] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 05/10/2015] [Indexed: 11/20/2022] Open
Abstract
The pulsatile release of GnRH is crucial for normal reproductive physiology across the life cycle, a process that is regulated by hypothalamic neurotransmitters. GnRH terminals co-express the vesicular glutamate transporter 2 (vGluT2) as a marker of a glutamatergic phenotype. The current study sought to elucidate the relationship between glutamate and GnRH nerve terminals in the median eminence—the site of GnRH release into the portal capillary vasculature. We also determined whether this co-expression may change during reproductive senescence, and if steroid hormones, which affect responsiveness of GnRH neurons to glutamate, may alter the co-expression pattern. Female Sprague-Dawley rats were ovariectomized at young adult, middle-aged and old ages (~4, 11, and 22 months, respectively) and treated four weeks later with sequential vehicle + vehicle (VEH + VEH), estradiol + vehicle (E2 + VEH), or estradiol + progesterone (E2+P4). Rats were perfused 24 hours after the second hormone treatment. Confocal microscopy was used to determine colocalization of GnRH and vGluT2 immunofluorescence in the median eminence. Post-embedding immunogold labeling of GnRH and vGluT2, and a serial electron microscopy (EM) technique were used to determine the cellular interaction between GnRH terminals and glutamate signaling. Confocal analysis showed that GnRH and vGluT2 immunofluorescent puncta were extensively colocalized in the median eminence and that their density declined with age but was unaffected by short-term hormone treatment. EM results showed that vGluT2 immunoreactivity was extensively associated with large dense-core vesicles, suggesting a unique glutamatergic signaling pathway in GnRH terminals. Our results provide novel subcellular information about the intimate relationship between GnRH terminals and glutamate in the median eminence.
Collapse
Affiliation(s)
- Weiling Yin
- Division of Pharmacology and Toxicology, College of Pharmacy, University of Texas at Austin, Austin, Texas, United States of America
| | - Zengrong Sun
- School of Public Health, Tianjin Medical University, Tianjin, China
| | - John M. Mendenhall
- Institute for Neuroscience, University of Texas at Austin, Austin, Texas, United States of America
| | - Deena M. Walker
- Institute for Neuroscience, University of Texas at Austin, Austin, Texas, United States of America
| | - Penny D. Riha
- Division of Pharmacology and Toxicology, College of Pharmacy, University of Texas at Austin, Austin, Texas, United States of America
| | - Kelsey S. Bezner
- Division of Pharmacology and Toxicology, College of Pharmacy, University of Texas at Austin, Austin, Texas, United States of America
| | - Andrea C. Gore
- Division of Pharmacology and Toxicology, College of Pharmacy, University of Texas at Austin, Austin, Texas, United States of America
- Institute for Neuroscience, University of Texas at Austin, Austin, Texas, United States of America
- Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas, United States of America
- * E-mail:
| |
Collapse
|
35
|
Sdrulla AD, Xu Q, He SQ, Tiwari V, Yang F, Zhang C, Shu B, Shechter R, Raja SN, Wang Y, Dong X, Guan Y. Electrical stimulation of low-threshold afferent fibers induces a prolonged synaptic depression in lamina II dorsal horn neurons to high-threshold afferent inputs in mice. Pain 2015; 156:1008-1017. [PMID: 25974163 PMCID: PMC4437220 DOI: 10.1097/01.j.pain.0000460353.15460.a3] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Electrical stimulation of low-threshold Aβ-fibers (Aβ-ES) is used clinically to treat neuropathic pain conditions that are refractory to pharmacotherapy. However, it is unclear how Aβ-ES modulates synaptic responses to high-threshold afferent inputs (C-, Aδ-fibers) in superficial dorsal horn. Substantia gelatinosa (SG) (lamina II) neurons are important for relaying and modulating converging spinal nociceptive inputs. We recorded C-fiber-evoked excitatory postsynaptic currents (eEPSCs) in spinal cord slices in response to paired-pulse test stimulation (500 μA, 0.1 millisecond, 400 milliseconds apart). We showed that 50-Hz and 1000-Hz, but not 4-Hz, Aβ-ES (10 μA, 0.1 millisecond, 5 minutes) induced prolonged inhibition of C-fiber eEPSCs in SG neurons in naive mice. Furthermore, 50-Hz Aβ-ES inhibited both monosynaptic and polysynaptic forms of C-fiber eEPSC in naive mice and mice that had undergone spinal nerve ligation (SNL). The paired-pulse ratio (amplitude second eEPSC/first eEPSC) increased only in naive mice after 50-Hz Aβ-ES, suggesting that Aβ-ES may inhibit SG neurons by different mechanisms under naive and nerve-injured conditions. Finally, 50-Hz Aβ-ES inhibited both glutamatergic excitatory and GABAergic inhibitory interneurons, which were identified by fluorescence in vGlut2-Td and glutamic acid decarboxylase-green fluorescent protein transgenic mice after SNL. These findings show that activities in Aβ-fibers lead to frequency-dependent depression of synaptic transmission in SG neurons in response to peripheral noxious inputs. However, 50-Hz Aβ-ES failed to induce cell-type-selective inhibition in SG neurons. The physiologic implication of this novel form of synaptic depression for pain modulation by Aβ-ES warrants further investigation.
Collapse
Affiliation(s)
- Andrei D. Sdrulla
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, Maryland, 21205
| | - Qian Xu
- The Solomon H. Snyder Department of Neuroscience, Center for Sensory Biology, Johns Hopkins University, School of Medicine, Baltimore, Maryland, 21205
- Howard Hughes Medical Institute, Johns Hopkins University, School of Medicine, Baltimore, Maryland, 21205
| | - Shao-Qiu He
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, Maryland, 21205
| | - Vinod Tiwari
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, Maryland, 21205
| | - Fei Yang
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, Maryland, 21205
| | - Chen Zhang
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, Maryland, 21205
- Department of Anesthesiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing 100020, China
| | - Bin Shu
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, Maryland, 21205
| | - Ronen Shechter
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, Maryland, 21205
| | - Srinivasa N. Raja
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, Maryland, 21205
| | - Yun Wang
- Department of Anesthesiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing 100020, China
| | - Xinzhong Dong
- The Solomon H. Snyder Department of Neuroscience, Center for Sensory Biology, Johns Hopkins University, School of Medicine, Baltimore, Maryland, 21205
- Howard Hughes Medical Institute, Johns Hopkins University, School of Medicine, Baltimore, Maryland, 21205
| | - Yun Guan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, Maryland, 21205
| |
Collapse
|
36
|
Dorofeeva NA, Glazova MV, Khudik KA, Nikitina LS, Kirillova D, Chernigovskaya EV. [COMPARATIVE STUDY OF NIGROSTRIATAL SYSTEMS IN WISTAR RATS AND RATS PRONE TO SEIZURES]. Zh Evol Biokhim Fiziol 2015; 51:204-213. [PMID: 26281223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In this work we analyzed the levels of functional activity of dopaminergic, GABA-ergic and glutamatergic neurons in the nigrostriatal system of control Wistar rats and Krushinsky-Molodkina (KM) rats prone to audiogenic seizures. In KM rats we have revealed disturbed activity of GABA- and dopaminergic neurons in substania nigra whereas the level of glutamatergic neurotransmission remained unchanged. We have also observed no significant differences in GAD65/67 and phospho-tyrosine hydroxylase contents in the striatum of KM and control Wistar rats. However, a high level of D1 dopamine receptor and a decreased level of D2 receptor found can mediate the upregulation of glutamatergic neurotransmission. Indeed, the expression of vesicular glutamate transporter type 2 (VGlut2) and NR2B subunit of NMDA receptor was increased in the striatum of KM rats. In striatal glutamatergic fibers phosphorylated ERK1/2 kinases have been revealed; at the same time, in KM rats an increased ERK1/2 activity has been detected both in striatum and substantia nigra. This finding correlated with activation of exocytosis rate as evidenced by downregulation of SNAP25 level. Apart from other reasons, the activation of glutamatergic system may be a result of disruption of the inhibitory effect of the dopamine- and GABAergic systems of substantia nigra that innervate striatum. We suppose that the increased activity of striatal glutamatergic neurons of KM rats without an adequate inhibition by GABA- and dopaminergic systems may be one of the reasons of high convulsive susceptibility in KM rats.
Collapse
|
37
|
Zhang S, Qi J, Li X, Wang HL, Britt JP, Hoffman AF, Bonci A, Lupica CR, Morales M. Dopaminergic and glutamatergic microdomains in a subset of rodent mesoaccumbens axons. Nat Neurosci 2015; 18:386-92. [PMID: 25664911 PMCID: PMC4340758 DOI: 10.1038/nn.3945] [Citation(s) in RCA: 174] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 01/13/2015] [Indexed: 12/14/2022]
Abstract
Mesoaccumbens fibers are thought to co-release dopamine and glutamate. However, the mechanism is unclear, and co-release by mesoaccumbens fibers has not been documented. Using electron microcopy, we found that some mesoaccumbens fibers have vesicular transporters for dopamine (VMAT2) in axon segments that are continuous with axon terminals that lack VMAT2, but contain vesicular glutamate transporters type 2 (VGluT2). In vivo overexpression of VMAT2 did not change the segregation of the two vesicular types, suggesting the existence of highly regulated mechanisms for maintaining this segregation. The mesoaccumbens axon terminals containing VGluT2 vesicles make asymmetric synapses, commonly associated with excitatory signaling. Using optogenetics, we found that dopamine and glutamate were released from the same mesoaccumbens fibers. These findings reveal a complex type of signaling by mesoaccumbens fibers in which dopamine and glutamate can be released from the same axons, but are not normally released at the same site or from the same synaptic vesicles.
Collapse
Affiliation(s)
- Shiliang Zhang
- National Institute on Drug Abuse, Neuronal Networks Section, US National Institutes of Health, Baltimore, Maryland, USA
| | - Jia Qi
- National Institute on Drug Abuse, Neuronal Networks Section, US National Institutes of Health, Baltimore, Maryland, USA
| | - Xueping Li
- National Institute on Drug Abuse, Neuronal Networks Section, US National Institutes of Health, Baltimore, Maryland, USA
| | - Hui-Ling Wang
- National Institute on Drug Abuse, Neuronal Networks Section, US National Institutes of Health, Baltimore, Maryland, USA
| | - Jonathan P. Britt
- National Institute on Drug Abuse, Synaptic Plasticity Section, US National Institutes of Health, Baltimore, Maryland, USA
| | - Alexander F. Hoffman
- National Institute on Drug Abuse, Electrophysiology Research Section, US National Institutes of Health, Baltimore, Maryland, USA
| | - Antonello Bonci
- National Institute on Drug Abuse, Synaptic Plasticity Section, US National Institutes of Health, Baltimore, Maryland, USA
| | - Carl R. Lupica
- National Institute on Drug Abuse, Electrophysiology Research Section, US National Institutes of Health, Baltimore, Maryland, USA
| | - Marisela Morales
- National Institute on Drug Abuse, Neuronal Networks Section, US National Institutes of Health, Baltimore, Maryland, USA
| |
Collapse
|
38
|
Rogoz K, Stjärne L, Kullander K, Lagerström MC. VGLUT2 controls heat and punctuate hyperalgesia associated with nerve injury via TRPV1-Cre primary afferents. PLoS One 2015; 10:e0116568. [PMID: 25615623 PMCID: PMC4304805 DOI: 10.1371/journal.pone.0116568] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 12/11/2014] [Indexed: 12/04/2022] Open
Abstract
Nerve injury induces a state of prolonged thermal and mechanical hypersensitivity in the innervated area, causing distress in affected individuals. Nerve injury-induced hypersensitivity is partially due to increased activity and thereby sustained release of neurotransmitters from the injured fibers. Glutamate, a prominent neurotransmitter in primary afferents, plays a major role in development of hypersensitivity. Glutamate is packed in vesicles by vesicular glutamate transporters (VGLUTs) to enable controlled release upon depolarization. While a role for peripheral VGLUTs in nerve injury-induced pain is established, their contribution in specific peripheral neuronal populations is unresolved. We investigated the role of VGLUT2, expressed by transient receptor potential vanilloid (TRPV1) fibers, in nerve injury-induced hypersensitivity. Our data shows that removal of Vglut2 from Trpv1-Cre neurons using transgenic mice abolished both heat and punctuate hyperalgesia associated with nerve injury. In contrast, the development of cold hypersensitivity after nerve injury was unaltered. Here, we show that, VGLUT2-mediated glutamatergic transmission from Trpv1-Cre neurons selectively mediates heat and mechanical hypersensitivity associated with nerve injury. Our data clarifies the role of the Trpv1-Cre population and the dependence of VGLUT2-mediated glutamatergic transmission in nerve injury-induced hyperalgesia.
Collapse
Affiliation(s)
- Katarzyna Rogoz
- Department of Neuroscience, Uppsala University, Uppsala, Sweden
| | - Ludvig Stjärne
- Department of Neuroscience, Uppsala University, Uppsala, Sweden
| | - Klas Kullander
- Department of Neuroscience, Uppsala University, Uppsala, Sweden
| | | |
Collapse
|
39
|
Atoji Y, Karim MR. Glutamatergic thalamopallial projections in the pigeon identified by retrograde labeling and expression of vGluT2 mRNA. Neurosci Res 2014; 84:43-6. [PMID: 24657707 DOI: 10.1016/j.neures.2014.03.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2013] [Revised: 03/06/2014] [Accepted: 03/07/2014] [Indexed: 11/19/2022]
Abstract
A neocortical hypothesis as to homology of certain nuclear components of the avian brain proposes that the entopallium and field L2 are homologous to layer 4 of mammalian extrastriate and auditory neocortex, respectively. However, the hypothesis lacks support from the neurochemistry of thalamopallial projections. We investigated whether these projections are glutamatergic by injecting cholera toxin B into either the entopallium or field L2 in combination with in situ hybridization. Retrogradely labeled neurons in nucleus rotundus and nucleus ovoidalis were found to express vesicular glutamate transporter 2 mRNA, showing that the thalamopallial projections are glutamatergic. The results are consistent with the neocortical hypothesis.
Collapse
Affiliation(s)
- Yasuro Atoji
- Laboratory of Veterinary Anatomy, Faculty of Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan.
| | - Mohammad Rabiul Karim
- Laboratory of Veterinary Anatomy, Faculty of Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan; Department of Anatomy and Histology, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh
| |
Collapse
|
40
|
Apostolides PF, Trussell LO. Regulation of interneuron excitability by gap junction coupling with principal cells. Nat Neurosci 2013; 16:1764-72. [PMID: 24185427 PMCID: PMC3963432 DOI: 10.1038/nn.3569] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 09/30/2013] [Indexed: 12/14/2022]
Abstract
Electrical coupling of inhibitory interneurons can synchronize activity across multiple neurons, thereby enhancing the reliability of inhibition onto principal cell targets. It is unclear whether downstream activity in principal cells controls the excitability of such inhibitory networks. Using paired patch-clamp recordings, we show that excitatory projection neurons (fusiform cells) and inhibitory stellate interneurons of the dorsal cochlear nucleus form an electrically coupled network through gap junctions containing connexin36 (Cxc36, also called Gjd2). Remarkably, stellate cells were more strongly coupled to fusiform cells than to other stellate cells. This heterologous coupling was functionally asymmetric, biasing electrical transmission from the principal cell to the interneuron. Optogenetically activated populations of fusiform cells reliably enhanced interneuron excitability and generated GABAergic inhibition onto the postsynaptic targets of stellate cells, whereas deep afterhyperpolarizations following fusiform cell spike trains potently inhibited stellate cells over several hundred milliseconds. Thus, the excitability of an interneuron network is bidirectionally controlled by distinct epochs of activity in principal cells.
Collapse
Affiliation(s)
- Pierre F Apostolides
- 1] Neuroscience Graduate Program, Oregon Health and Science University, Portland, Oregon, USA. [2] Vollum Institute and Oregon Hearing Research Center, Oregon Health and Science University, Portland, Oregon, USA
| | | |
Collapse
|
41
|
Wittmann G, Hrabovszky E, Lechan RM. Distinct glutamatergic and GABAergic subsets of hypothalamic pro-opiomelanocortin neurons revealed by in situ hybridization in male rats and mice. J Comp Neurol 2013; 521:3287-302. [PMID: 23640796 PMCID: PMC4003895 DOI: 10.1002/cne.23350] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Revised: 04/07/2013] [Accepted: 04/25/2013] [Indexed: 11/10/2022]
Abstract
Pro-opiomelanocortin (POMC) and agouti-related protein (AGRP) neurons in the hypothalamus regulate various aspects of energy homeostasis and metabolism. POMC and AGRP neurons, respectively, agonize and antagonize melanocortin receptors on their common downstream neurons. However, it is unknown whether they also reciprocally stimulate and inhibit the same neurons by amino acid transmitters. Whereas AGRP neurons are mostly GABAergic, surprisingly, only a small population of POMC neurons has been found to be glutamatergic, and a significantly larger subpopulation to be GABAergic. To further examine amino acid phenotypes of POMC neurons, we studied mRNA expression for the glutamatergic marker, type 2 vesicular glutamate transporter (VGLUT2), and the GABA synthetic enzyme, glutamic acid decarboxylase 67 (GAD67), in POMC neurons of both rats and mice by using in situ hybridization techniques. In rats, approximately 58% of POMC neurons were labeled for VGLUT2 and 37% for GAD67 mRNA. In mice, approximately 43% of POMC neurons contained VGLUT2, and 54% contained GAD67 mRNA. In both species, a prominent mediolateral distribution pattern was observed at rostral and mid levels of the POMC cell group with VGLUT2-POMC neurons dominating in lateral portions and GAD67-POMC neurons in medial portions. These data demonstrate that both glutamatergic and GABAergic cells are present in comparably significant numbers among POMC neurons. Their glutamatergic or GABAergic phenotype may represent a major functional division within the POMC cell group.
Collapse
Affiliation(s)
- Gábor Wittmann
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Tupper Research Institute, Tufts Medical Center, Boston, Massachusetts 02111
| | - Erik Hrabovszky
- Department of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest 1083, Hungary
| | - Ronald M. Lechan
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Tupper Research Institute, Tufts Medical Center, Boston, Massachusetts 02111
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111
| |
Collapse
|
42
|
Bui TV, Akay T, Loubani O, Hnasko TS, Jessell TM, Brownstone RM. Circuits for grasping: spinal dI3 interneurons mediate cutaneous control of motor behavior. Neuron 2013; 78:191-204. [PMID: 23583114 DOI: 10.1016/j.neuron.2013.02.007] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/01/2013] [Indexed: 11/18/2022]
Abstract
Accurate motor performance depends on the integration in spinal microcircuits of sensory feedback information. Hand grasp is a skilled motor behavior known to require cutaneous sensory feedback, but spinal microcircuits that process and relay this feedback to the motor system have not been defined. We sought to define classes of spinal interneurons involved in the cutaneous control of hand grasp in mice and to show that dI3 interneurons, a class of dorsal spinal interneurons marked by the expression of Isl1, convey input from low threshold cutaneous afferents to motoneurons. Mice in which the output of dI3 interneurons has been inactivated exhibit deficits in motor tasks that rely on cutaneous afferent input. Most strikingly, the ability to maintain grip strength in response to increasing load is lost following genetic silencing of dI3 interneuron output. Thus, spinal microcircuits that integrate cutaneous feedback crucial for paw grip rely on the intermediary role of dI3 interneurons.
Collapse
Affiliation(s)
- Tuan V Bui
- Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | | | | | | | | | | |
Collapse
|
43
|
Melo CV, Mele M, Curcio M, Comprido D, Silva CG, Duarte CB. BDNF regulates the expression and distribution of vesicular glutamate transporters in cultured hippocampal neurons. PLoS One 2013; 8:e53793. [PMID: 23326507 PMCID: PMC3543267 DOI: 10.1371/journal.pone.0053793] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Accepted: 12/05/2012] [Indexed: 11/18/2022] Open
Abstract
BDNF is a pro-survival protein involved in neuronal development and synaptic plasticity. BDNF strengthens excitatory synapses and contributes to LTP, presynaptically, through enhancement of glutamate release, and postsynaptically, via phosphorylation of neurotransmitter receptors, modulation of receptor traffic and activation of the translation machinery. We examined whether BDNF upregulated vesicular glutamate receptor (VGLUT) 1 and 2 expression, which would partly account for the increased glutamate release in LTP. Cultured rat hippocampal neurons were incubated with 100 ng/ml BDNF, for different periods of time, and VGLUT gene and protein expression were assessed by real-time PCR and immunoblotting, respectively. At DIV7, exogenous application of BDNF rapidly increased VGLUT2 mRNA and protein levels, in a dose-dependent manner. VGLUT1 expression also increased but only transiently. However, at DIV14, BDNF stably increased VGLUT1 expression, whilst VGLUT2 levels remained low. Transcription inhibition with actinomycin-D or α-amanitine, and translation inhibition with emetine or anisomycin, fully blocked BDNF-induced VGLUT upregulation. Fluorescence microscopy imaging showed that BDNF stimulation upregulates the number, integrated density and intensity of VGLUT1 and VGLUT2 puncta in neurites of cultured hippocampal neurons (DIV7), indicating that the neurotrophin also affects the subcellular distribution of the transporter in developing neurons. Increased VGLUT1 somatic signals were also found 3 h after stimulation with BDNF, further suggesting an increased de novo transcription and translation. BDNF regulation of VGLUT expression was specifically mediated by BDNF, as no effect was found upon application of IGF-1 or bFGF, which activate other receptor tyrosine kinases. Moreover, inhibition of TrkB receptors with K252a and PLCγ signaling with U-73122 precluded BDNF-induced VGLUT upregulation. Hippocampal neurons express both isoforms during embryonic and neonatal development in contrast to adult tissue expressing only VGLUT1. These results suggest that BDNF regulates VGLUT expression during development and its effect on VGLUT1 may contribute to enhance glutamate release in LTP.
Collapse
Affiliation(s)
- Carlos V. Melo
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Miranda Mele
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Michele Curcio
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- Department of Biological and Environmental Science, University of Sannio, Benevento, Italy
| | - Diogo Comprido
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Carla G. Silva
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Carlos B. Duarte
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- Department of Life Sciences, University of Coimbra, Coimbra, Portugal
- * E-mail:
| |
Collapse
|
44
|
Fortin GM, Bourque MJ, Mendez JA, Leo D, Nordenankar K, Birgner C, Arvidsson E, Rymar VV, Bérubé-Carrière N, Claveau AM, Descarries L, Sadikot AF, Wallén-Mackenzie Å, Trudeau LÉ. Glutamate corelease promotes growth and survival of midbrain dopamine neurons. J Neurosci 2012; 32:17477-91. [PMID: 23197738 PMCID: PMC6621856 DOI: 10.1523/jneurosci.1939-12.2012] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Revised: 10/10/2012] [Accepted: 10/16/2012] [Indexed: 01/09/2023] Open
Abstract
Recent studies have proposed that glutamate corelease by mesostriatal dopamine (DA) neurons regulates behavioral activation by psychostimulants. How and when glutamate release by DA neurons might play this role remains unclear. Considering evidence for early expression of the type 2 vesicular glutamate transporter in mesencephalic DA neurons, we hypothesized that this cophenotype is particularly important during development. Using a conditional gene knock-out approach to selectively disrupt the Vglut2 gene in mouse DA neurons, we obtained in vitro and in vivo evidence for reduced growth and survival of mesencephalic DA neurons, associated with a decrease in the density of DA innervation in the nucleus accumbens, reduced activity-dependent DA release, and impaired motor behavior. These findings provide strong evidence for a functional role of the glutamatergic cophenotype in the development of mesencephalic DA neurons, opening new perspectives into the pathophysiology of neurodegenerative disorders involving the mesostriatal DA system.
Collapse
Affiliation(s)
- Guillaume M Fortin
- Department of Pharmacology, and Groupe de Recherche sur le Système Nerveux Central, Faculty of Medicine, Université de Montréal, Montréal, Québec, Canada H3C 3J7
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Abstract
Thermoregulatory neurons of the median preoptic nucleus (MnPO) represent a target at which histamine modulates body temperature. The mechanism by which histamine excites a population of MnPO neurons is not known. In this study it was found that histamine activated a cationic inward current and increased the intracellular Ca(2+) concentration, actions that had a transient component as well as a sustained one that lasted for tens of minutes after removal of the agonist. The sustained component was blocked by TRPC channel blockers. Single-cell reverse transcription-PCR analysis revealed expression of TRPC1, TRPC5 and TRPC7 subunits in neurons excited by histamine. These studies also established the presence of transcripts for the glutamatergic marker Vglut2 and for the H1 histamine receptor in neurons excited by histamine. Intracellular application of antibodies directed against cytoplasmic sites of the TRPC1 or TRPC5 channel subunits decreased the histamine-induced inward current. The persistent inward current and elevation in intracellular Ca(2+) concentration could be reversed by activating the PKA pathway. This data reveal a novel mechanism by which histamine induces persistent excitation and sustained intracellular Ca(2+) elevation in glutamatergic MnPO neurons.
Collapse
Affiliation(s)
- Iustin V Tabarean
- The Department of Molecular and Integrative Neurosciences, The Scripps Research Institute, La Jolla, California, USA.
| |
Collapse
|
46
|
Barker M, Solinski HJ, Hashimoto H, Tagoe T, Pilati N, Hamann M. Acoustic overexposure increases the expression of VGLUT-2 mediated projections from the lateral vestibular nucleus to the dorsal cochlear nucleus. PLoS One 2012; 7:e35955. [PMID: 22570693 PMCID: PMC3343051 DOI: 10.1371/journal.pone.0035955] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Accepted: 03/28/2012] [Indexed: 11/19/2022] Open
Abstract
The dorsal cochlear nucleus (DCN) is a first relay of the central auditory system as well as a site for integration of multimodal information. Vesicular glutamate transporters VGLUT-1 and VGLUT-2 selectively package glutamate into synaptic vesicles and are found to have different patterns of organization in the DCN. Whereas auditory nerve fibers predominantly co-label with VGLUT-1, somatosensory inputs predominantly co-label with VGLUT-2. Here, we used retrograde and anterograde transport of fluorescent conjugated dextran amine (DA) to demonstrate that the lateral vestibular nucleus (LVN) exhibits ipsilateral projections to both fusiform and deep layers of the rat DCN. Stimulating the LVN induced glutamatergic synaptic currents in fusiform cells and granule cell interneurones. We combined the dextran amine neuronal tracing method with immunohistochemistry and showed that labeled projections from the LVN are co-labeled with VGLUT-2 by contrast to VGLUT-1. Wistar rats were exposed to a loud single tone (15 kHz, 110 dB SPL) for 6 hours. Five days after acoustic overexposure, the level of expression of VGLUT-1 in the DCN was decreased whereas the level of expression of VGLUT-2 in the DCN was increased including terminals originating from the LVN. VGLUT-2 mediated projections from the LVN to the DCN are likely to play a role in the head position in response to sound. Amplification of VGLUT-2 expression after acoustic overexposure could be a compensatory mechanism from vestibular inputs in response to hearing loss and to a decrease of VGLUT-1 expression from auditory nerve fibers.
Collapse
Affiliation(s)
- Matthew Barker
- Department of Cell Physiology and Pharmacology, Leicester University, Leicester, United Kingdom
| | - Hans Jürgen Solinski
- Department of Cell Physiology and Pharmacology, Leicester University, Leicester, United Kingdom
| | - Haruka Hashimoto
- Department of Cell Physiology and Pharmacology, Leicester University, Leicester, United Kingdom
| | - Thomas Tagoe
- Department of Cell Physiology and Pharmacology, Leicester University, Leicester, United Kingdom
| | - Nadia Pilati
- Department of Cell Physiology and Pharmacology, Leicester University, Leicester, United Kingdom
| | - Martine Hamann
- Department of Cell Physiology and Pharmacology, Leicester University, Leicester, United Kingdom
| |
Collapse
|
47
|
Koch SM, Dela Cruz CG, Hnasko TS, Edwards RH, Huberman AD, Ullian EM. Pathway-specific genetic attenuation of glutamate release alters select features of competition-based visual circuit refinement. Neuron 2011; 71:235-42. [PMID: 21791283 DOI: 10.1016/j.neuron.2011.05.045] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/26/2011] [Indexed: 11/17/2022]
Abstract
A hallmark of mammalian neural circuit development is the refinement of initially imprecise connections by competitive activity-dependent processes. In the developing visual system retinal ganglion cell (RGC) axons from the two eyes undergo activity-dependent competition for territory in the dorsal lateral geniculate nucleus (dLGN). The direct contributions of synaptic transmission to this process, however, remain unclear. We used a genetic approach to reduce glutamate release selectively from ipsilateral-projecting RGCs and found that their release-deficient axons failed to exclude competing axons from the ipsilateral eye territory in the dLGN. Nevertheless, the release-deficient axons consolidated and maintained their normal amount of dLGN territory, even in the face of fully active competing axons. These results show that during visual circuit refinement glutamatergic transmission plays a direct role in excluding competing axons from inappropriate target regions, but they argue that consolidation and maintenance of axonal territory are largely insensitive to alterations in synaptic activity levels.
Collapse
Affiliation(s)
- Selina M Koch
- Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA 94143, USA
| | | | | | | | | | | |
Collapse
|
48
|
Abstract
There are three paralogous genes for gonadotrophin-releasing hormone (GnRH) peptides of vertebrates in general. GnRH1, the protein product of gnrh1 gene, is the hypophysiotrophic neuropeptide, and is a critical regulator of gonadotrophin secretion, whereas GnRH2 and GnRH3 are regarded to have neuromodulatory functions. In some teleost species, the terminal nerve (TN) GnRH3 neuronal system, which expresses GnRH3, has been shown to project extensively throughout the brain and regulate the motivational state for some behavioural repertoires. In recent years, it has been considered that most, if not all, peptidergic and aminergic neurones synthesise and release more than one neurotransmitter, and the cotransmission of conventional small-molecule neurotransmitters, such as GABA, glutamate or acetylcholine together with neuropeptides, is regarded as a common feature of such neurones. For a functional characterisation of the GnRH3 neuronal system, we examined the possible co-expression of conventional neurotransmitters, GABA, acetylcholine and glutamate, in addition to GnRH in the TN-GnRH3 neurone by reverse transcriptase-polymerase chain reaction (RT-PCR) and in situ hybridisation of recently identified marker genes for neurotransmitters using a teleost fish medaka (Oryzias latipes). By RT-PCR and dual-label in situ hybridisation, we demonstrated the co-expression of GnRH3 and vesicular transporter for glutamate (VGluT) 2.1. in a single TN-GnRH3 neurone. We therefore suggest that the TN-GnRH3 neurones use glutamate as a cotransmitter of GnRH.
Collapse
Affiliation(s)
- Y Akazome
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | | | | |
Collapse
|
49
|
Ulrich-Lai YM, Jones KR, Ziegler DR, Cullinan WE, Herman JP. Forebrain origins of glutamatergic innervation to the rat paraventricular nucleus of the hypothalamus: differential inputs to the anterior versus posterior subregions. J Comp Neurol 2011; 519:1301-19. [PMID: 21452198 PMCID: PMC3893028 DOI: 10.1002/cne.22571] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The hypothalamic paraventricular nucleus (PVN) regulates numerous homeostatic systems and functions largely under the influence of forebrain inputs. Glutamate is a major neurotransmitter in forebrain, and glutamate neurosignaling in the PVN is known to mediate many of its functions. Previous work showed that vesicular glutamate transporters (VGluTs; specific markers for glutamatergic neurons) are expressed in forebrain sites that project to the PVN; however, the extent of this presumed glutamatergic innervation to the PVN is not clear. In the present study retrograde FluoroGold (FG) labeling of PVN-projecting neurons was combined with in situ hybridization for VGluT1 and VGluT2 mRNAs to identify forebrain regions that provide glutamatergic innervation to the PVN and its immediate surround in rats, with special consideration for the sources to the anterior versus posterior PVN. VGluT1 mRNA colocalization with retrogradely labeled FG neurons was sparse. VGluT2 mRNA colocalization with FG neurons was most abundant in the ventromedial hypothalamus after anterior PVN FG injections, and in the lateral, posterior, dorsomedial, and ventromedial hypothalamic nuclei after posterior PVN injections. Anterograde tract tracing combined with VGluT2 immunolabeling showed that 1) ventromedial nucleus-derived glutamatergic inputs occur in both the anterior and posterior PVN; 2) posterior nucleus-derived glutamatergic inputs occur predominantly in the posterior PVN; and 3) medial preoptic nucleus-derived inputs to the PVN are not glutamatergic, thereby corroborating the innervation pattern seen with retrograde tracing. The results suggest that PVN subregions are influenced by varying amounts and sources of forebrain glutamatergic regulation, consistent with functional differentiation of glutamate projections.
Collapse
Affiliation(s)
- Yvonne M Ulrich-Lai
- Department of Psychiatry, University of Cincinnati, Cincinnati, Ohio 45267, USA.
| | | | | | | | | |
Collapse
|
50
|
Dimitrov EL, Petrus E, Usdin TB. Tuberoinfundibular peptide of 39 residues (TIP39) signaling modulates acute and tonic nociception. Exp Neurol 2010; 226:68-83. [PMID: 20696160 DOI: 10.1016/j.expneurol.2010.08.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Revised: 07/26/2010] [Accepted: 08/02/2010] [Indexed: 11/19/2022]
Abstract
Tuberoinfundibular peptide of 39 residues (TIP39) synthesizing neurons at the caudal border of the thalamus and in the lateral pons project to areas rich in its receptor, the parathyroid hormone 2 receptor (PTH2R). These areas include many involved in processing nociceptive information. Here we examined the potential role of TIP39 signaling in nociception using a PTH2R antagonist (HYWH) and mice with deletion of TIP39's coding sequence or PTH2R null mutation. Intracerebroventricular (icv) infusion of HYWH significantly inhibited nociceptive responses in tail-flick and hot-plate tests and attenuated the nociceptive response to hindpaw formalin injection. TIP39-KO and PTH2R-KO had increased response latency in the 55°C hot-plate test and reduced responses in the hindpaw formalin test. The tail-flick test was not affected in either KO line. Thermal hypoalgesia in KO mice was dose-dependently reversed by systemic administration of the cannabinoid receptor 1 (CB1) antagonist rimonabant, which did not affect nociception in wild-type (WT). Systemic administration of the cannabinoid agonist CP 55,940 did not affect nociception in KO mice at a dose effective in WT. WT mice administered HYWH icv, and both KOs, had significantly increased stress-induced analgesia (SIA). Rimonabant blocked the increased SIA in TIP39-KO, PTH2R-KO or after HYWH infusion. CB1 and FAAH mRNA were decreased and increased, respectively, in the basolateral amygdala of TIP39-KO mice. These data suggest that TIP39 signaling modulates nociception, very likely by inhibiting endocannabinoid circuitry at a supraspinal level. We infer a new central mechanism for endocannabinoid regulation, via TIP39 acting on the PTH2R in discrete brain regions.
Collapse
MESH Headings
- Amidohydrolases/metabolism
- Animals
- Cannabinoid Receptor Modulators/metabolism
- Formaldehyde
- In Situ Hybridization
- Injections, Intraventricular
- Injections, Spinal
- Male
- Mice
- Mice, Knockout
- Naloxone/pharmacology
- Narcotic Antagonists/pharmacology
- Neuropeptides/administration & dosage
- Neuropeptides/pharmacology
- Nociceptors/drug effects
- Nociceptors/physiology
- Pain/pathology
- Pain/physiopathology
- Pain Measurement/drug effects
- Piperidines/pharmacology
- Pyrazoles/pharmacology
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- Receptor, Cannabinoid, CB1/antagonists & inhibitors
- Receptor, Cannabinoid, CB1/biosynthesis
- Receptor, Parathyroid Hormone, Type 2/biosynthesis
- Receptor, Parathyroid Hormone, Type 2/genetics
- Rimonabant
- Signal Transduction/physiology
- Stress, Psychological/psychology
- Synapses/physiology
- Vesicular Glutamate Transport Protein 2/biosynthesis
- Vesicular Glutamate Transport Protein 2/genetics
Collapse
Affiliation(s)
- Eugene L Dimitrov
- Section on Fundamental Neuroscience, National Institute of Mental Health, 35 Convent Drive, Room 1B-213, Bethesda, MD 20892, USA.
| | | | | |
Collapse
|