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Mei B, Xu X, Weng J, Yang Y, Wang P, Qiu G, Zhang C, Zhang Q, Lu Y, Liu X. Activating astrocytic α2A adrenoceptors in hippocampus reduces glutamate toxicity to attenuate sepsis-associated encephalopathy in mice. Brain Behav Immun 2024; 117:376-398. [PMID: 38320682 DOI: 10.1016/j.bbi.2024.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Revised: 12/09/2023] [Accepted: 02/02/2024] [Indexed: 02/08/2024] Open
Abstract
BACKGROUND Glutamate metabolism disorder is an important mechanism of sepsis-associated encephalopathy (SAE). Astrocytes regulate glutamate metabolism. In septic mice, α2A adrenoceptor (α2A-AR) activation in the central nervous system provides neuroprotection. α2A-ARs are expressed abundantly in hippocampal astrocytes. This study was performed to determine whether hippocampal astrocytic α2A-AR activation confers neuroprotection against SAE and whether this protective effect is astrocyte specific and achieved by the modulation of glutamate metabolism. METHODS Male C57BL/6 mice with and without α2A-AR knockdown were subjected to cecal ligation and puncture (CLP). They were treated with intrahippocampal guanfacine (an α2A-AR agonist) or intraperitoneal dexmedetomidine in the presence or absence of dihydrokainic acid [DHK; a glutamate transporter 1 (GLT-1) antagonist] and/or UCPH-101 [a glutamate/aspartate transporter (GLAST) antagonist]. Hippocampal tissue was collected for the measurement of astrocyte reactivity, GLT-1 and GLAST expression, and glutamate receptor subunit 2B (GluN2B) phosphorylation. In vivo real-time extracellular glutamate concentrations in the hippocampus were measured by ultra-performance liquid chromatography tandem mass spectrometry combined with microdialysis, and in vivo real-time hippocampal glutamatergic neuron excitability was assessed by calcium imaging. The mice were subjected to the Barnes maze and fear conditioning tests to assess their learning and memory. Golgi staining was performed to assess changes in the hippocampal synaptic structure. In vitro, primary astrocytes with and without α2A-AR knockdown were stimulated with lipopolysaccharide (LPS) and treated with guanfacine or dexmedetomidine in the presence or absence of 8-bromo- cyclic adenosine monophosphate (8-Br-cAMP, a cAMP analog). LPS-treated primary and BV2 microglia were also treated with guanfacine or dexmedetomidine. Astrocyte reactivity, PKA catalytic subunit, GLT-1 an GLAST expression were determined in primary astrocytes. Interleukin-1β, interleukin-6 and tumor necrosis factor-alpha in the medium of microglia culture were measured. RESULTS CLP induced synaptic injury, impaired neurocognitive function, increased astrocyte reactivity and reduced GLT-1 and GLAST expression in the hippocampus of mice. The extracellular glutamate concentration, phosphorylation of GluN2B at Tyr-1472 and glutamatergic neuron excitability in the hippocampus were increased in the hippocampus of septic mice. Intraperitoneal dexmedetomidine or intrahippocampal guanfacine administration attenuated these effects. Hippocampal astrocytes expressed abundant α2A-ARs; expression was also detected in neurons but not microglia. Specific knockdown of α2A-ARs in hippocampal astrocytes and simultaneous intrahippocampal DHK and UCPH-101 administration blocked the neuroprotective effects of dexmedetomidine and guanfacine. Intrahippocampal administration of DHK or UCPH-101 alone had no such effect. In vitro, guanfacine or dexmedetomidine inhibited astrocyte reactivity, reduced PKA catalytic subunit expression, and increased GLT-1 and GLAST expression in primary astrocytes but not in primary astrocytes that received α2A-AR knockdown or were treated with 8-Br-cAMP. Guanfacine or dexmedetomidine inhibited microglial reactivity in BV2 but not primary microglia. CONCLUSIONS Our results suggest that neurocognitive protection against SAE after hippocampal α2A-AR activation is astrocyte specific. This protection may involve the inhibition of astrocyte reactivity and alleviation of glutamate neurotoxicity, thereby reducing synaptic injury. The cAMP/protein kinase A (PKA) signaling pathway is a potential cellular mechanism by which activating α2A-AR modulates astrocytic function.
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Affiliation(s)
- Bin Mei
- Department of Anesthesiology, the First Affiliated Hospital of Anhui Medical University, Key Laboratory of Anesthesiology and Perioperative Medicine of Anhui Higher Education Institutes, Anhui Medical University, Hefei, Anhui Province, 230022, China.
| | - Xiaoxia Xu
- Department of Anesthesiology, the First Affiliated Hospital of Anhui Medical University, Key Laboratory of Anesthesiology and Perioperative Medicine of Anhui Higher Education Institutes, Anhui Medical University, Hefei, Anhui Province, 230022, China
| | - Juntao Weng
- Department of Anesthesiology, the First Affiliated Hospital of Anhui Medical University, Key Laboratory of Anesthesiology and Perioperative Medicine of Anhui Higher Education Institutes, Anhui Medical University, Hefei, Anhui Province, 230022, China
| | - Yueyue Yang
- Department of Anesthesiology, the First Affiliated Hospital of Anhui Medical University, Key Laboratory of Anesthesiology and Perioperative Medicine of Anhui Higher Education Institutes, Anhui Medical University, Hefei, Anhui Province, 230022, China
| | - Peng Wang
- Department of Anesthesiology, the First Affiliated Hospital of Anhui Medical University, Key Laboratory of Anesthesiology and Perioperative Medicine of Anhui Higher Education Institutes, Anhui Medical University, Hefei, Anhui Province, 230022, China
| | - Gaolin Qiu
- Department of Anesthesiology, the First Affiliated Hospital of Anhui Medical University, Key Laboratory of Anesthesiology and Perioperative Medicine of Anhui Higher Education Institutes, Anhui Medical University, Hefei, Anhui Province, 230022, China
| | - Chi Zhang
- School of Pharmacy, Anhui Medical University, Hefei, Anhui Province, 230001, China
| | - Qunlin Zhang
- School of Pharmacy, Anhui Medical University, Hefei, Anhui Province, 230001, China
| | - Yao Lu
- Department of Anesthesiology, the First Affiliated Hospital of Anhui Medical University, Key Laboratory of Anesthesiology and Perioperative Medicine of Anhui Higher Education Institutes, Anhui Medical University, Hefei, Anhui Province, 230022, China
| | - Xuesheng Liu
- Department of Anesthesiology, the First Affiliated Hospital of Anhui Medical University, Key Laboratory of Anesthesiology and Perioperative Medicine of Anhui Higher Education Institutes, Anhui Medical University, Hefei, Anhui Province, 230022, China.
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Wang JY, Liu Y, Qiu DL, Chu CP. Activation of α 2A and α 2B -adrenergic receptors inhibits tactile stimulation-evoked parallel fiber-Purkinje cell synaptic transmission in mouse cerebellar cortex. Neuroreport 2024; 35:115-122. [PMID: 38109417 PMCID: PMC10766093 DOI: 10.1097/wnr.0000000000001983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 11/15/2023] [Indexed: 12/20/2023]
Abstract
The mechanism by which α2-adrenergic receptors (ARs) modulate the cerebellar parallel fiber-Purkinje cell (PF-PC) synaptic transmission is unclear. We investigated this issue using electrophysiological and neuropharmacological methods. Six- to eight-week-old ICR mice were used in the study. Under in vivo conditions, PF-PC synaptic transmission was evoked by facial stimulation of ipsilateral whisker pad, and recorded using cell-attached patch from PCs. Under in-vitro conditions, PF-PC synaptic transmission was evoked by electrical stimulation of the molecular layer in cerebellar slices, and was recorded using whole-cell recording from PCs. SR95531 (20 µM) was added to the ACSF during all recordings to prevent GABAA receptor-mediated inhibition. Air-puff stimulation of the ipsilateral whisker pad in-vivo evoked simple spike (eSS) firing of cerebellar PCs. Microapplication of noradrenaline (15 µM) to the molecular layer significantly decreased the numbers and frequency of eSS, an effect abolished by the α2-AR antagonist. Microapplication of an α2-AR agonist, UK14304 (1 µM), significantly decreased the numbers of eSS in PCs, which was abolished by either α2A- or α2B-AR antagonist, but not by α2C-AR antagonist. Under in-vitro conditions, application of UK 14304 significantly decreased the amplitude of PF-PC EPSCs and increased the paired-pulse ratio, which were abolished by either α2A- or α2B-AR antagonist. The present results indicate that activation of presynaptic α2A- and α2B-AR downregulates PF-PC synaptic transmission in mouse cerebellar cortex.
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Affiliation(s)
- Jun-Ya Wang
- Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, Jilin Province
- Department of Physiology, College of Basic Medicine, Jilin Medical University, Jilin City, China
| | - Yue Liu
- Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, Jilin Province
- Department of Physiology, College of Basic Medicine, Jilin Medical University, Jilin City, China
| | - De-Lai Qiu
- Department of Physiology, College of Basic Medicine, Jilin Medical University, Jilin City, China
| | - Chun-Ping Chu
- Department of Physiology, College of Basic Medicine, Jilin Medical University, Jilin City, China
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Wang JY, Weng WC, Wang TQ, Liu Y, Qiu DL, Wu MC, Chu CP. Noradrenaline depresses facial stimulation-evoked cerebellar MLI-PC synaptic transmission via α2-AR/PKA signaling cascade in vivo in mice. Sci Rep 2023; 13:15908. [PMID: 37741947 PMCID: PMC10517918 DOI: 10.1038/s41598-023-42975-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 09/17/2023] [Indexed: 09/25/2023] Open
Abstract
The noradrenergic fibers of the locus coeruleus, together with mossy fibers and climbing fibers, comprise the three types of cerebellar afferents that modulate the cerebellar neuronal circuit. We previously demonstrated that noradrenaline (NA) modulated synaptic transmission in the mouse cerebellar cortex via adrenergic receptors (ARs). In the present study, we investigated the effect of NA on facial stimulation-evoked cerebellar molecular layer interneuron (MLI)-Purkinje cell (PC) synaptic transmission in urethane-anesthetized mice using an in vivo cell-attached recording technique and a pharmacological method. MLI-PC synaptic transmission was induced by air-puff stimulation (duration: 60 ms) of the ipsilateral whisker pad, which exhibited positive components (P1 and P2) accompanied by a pause in simple spike activity. Cerebellar molecular layer application of NA (15 µM) decreased the amplitude and area under the curve of P1, and the pause in simple spike activity, but increased the P2/P1 ratio. The NA-induced decrease in P1 amplitude was concentration-dependent, and the half-inhibitory concentration was 10.94 µM. The NA-induced depression of facial stimulation-evoked MLI-PC GABAergic synaptic transmission was completely abolished by blockade of α-ARs or α2-ARs, but not by antagonism of α1-ARs or β-ARs. Bath application of an α2-AR agonist inhibited MLI-PC synaptic transmission and attenuated the effect of NA on the synaptic response. NA-induced depression of MLI-PC synaptic transmission was completely blocked by a mixture of α2A- and 2B-AR antagonists, and was abolished by inhibition of protein kinase A. In addition, electrical stimulation of the molecular layer evoked MLI-PC GABAergic synaptic transmission in the presence of an AMPA receptor antagonist, which was inhibited by NA through α2-ARs. Our results indicate that NA inhibits MLI-PC GABAergic synaptic transmission by reducing GABA release via an α2-AR/PKA signaling pathway.
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Affiliation(s)
- Jun-Ya Wang
- Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, China
- Department of Physiology, College of Basic Medicine, Jilin Medical University, Jilin, 132013, Jilin, China
| | - Wen-Cai Weng
- Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, China
- Department Radiology, Dalian Xinhua Hospital, Dalian University, Dalian, China
| | - Ting-Qi Wang
- Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, China
| | - Yue Liu
- Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, China
- Department of Physiology, College of Basic Medicine, Jilin Medical University, Jilin, 132013, Jilin, China
| | - De-Lai Qiu
- Department of Physiology, College of Basic Medicine, Jilin Medical University, Jilin, 132013, Jilin, China
| | - Mao-Cheng Wu
- Department of Osteology, Affiliated Hospital of Yanbian University, Yanji, 133002, Jilin, China.
| | - Chun-Ping Chu
- Department of Physiology, College of Basic Medicine, Jilin Medical University, Jilin, 132013, Jilin, China.
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Pasierski M, Kołba W, Szulczyk B. Guanfacine inhibits interictal epileptiform events and sodium currents in prefrontal cortex pyramidal neurons. Pharmacol Rep 2023; 75:331-341. [PMID: 36800106 DOI: 10.1007/s43440-023-00458-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 01/27/2023] [Accepted: 01/30/2023] [Indexed: 02/18/2023]
Abstract
BACKGROUND Guanfacine (an alpha-2A receptor agonist) is a commonly used drug with recognized efficacy in the treatment of attention deficit hyperactivity disorder (ADHD). This study aimed to assess the effects of guanfacine on short-lasting (interictal) epileptiform discharges in cortical neurons. Moreover, we assessed the effects of guanfacine on voltage-gated sodium currents. METHODS We conducted patch-clamp recordings in prefrontal cortex pyramidal neurons obtained from young rats. Interictal epileptiform events were evoked in cortical slices in a zero magnesium proepileptic extracellular solution with an elevated concentration of potassium ions. RESULTS Interictal epileptiform discharges were spontaneous depolarisations, which triggered action potentials. Guanfacine (10 and 100 µM) inhibited the frequency of epileptiform discharges. The effect of guanfacine on interictal events persisted in the presence of alpha-2 adrenergic receptor antagonist idazoxan. The tested drug inhibited neuronal excitability. Tonic NMDA currents were not influenced by guanfacine. Recordings from dispersed neurons showed that the tested drug (10 and 100 µM) inhibited persistent and fast inactivating voltage-gated sodium currents. CONCLUSIONS This study shows that guanfacine inhibits interictal discharges in cortical neurons independently of alpha-2A adrenergic receptors. This effect may be mediated by voltage-gated sodium currents. Inhibition of interictal activity by guanfacine may be of clinical importance because interictal events often occur in patients with ADHD and may contribute to symptoms of this disease.
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Affiliation(s)
- Michał Pasierski
- Department of Pharmacodynamics, The Medical University of Warsaw, Banacha 1B, 02-097, Warsaw, Poland
| | - Weronika Kołba
- Department of Pharmacodynamics, The Medical University of Warsaw, Banacha 1B, 02-097, Warsaw, Poland
| | - Bartłomiej Szulczyk
- Department of Pharmacodynamics, The Medical University of Warsaw, Banacha 1B, 02-097, Warsaw, Poland.
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Ferré S, Belcher AM, Bonaventura J, Quiroz C, Sánchez-Soto M, Casadó-Anguera V, Cai NS, Moreno E, Boateng CA, Keck TM, Florán B, Earley CJ, Ciruela F, Casadó V, Rubinstein M, Volkow ND. Functional and pharmacological role of the dopamine D 4 receptor and its polymorphic variants. Front Endocrinol (Lausanne) 2022; 13:1014678. [PMID: 36267569 PMCID: PMC9578002 DOI: 10.3389/fendo.2022.1014678] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 09/14/2022] [Indexed: 11/13/2022] Open
Abstract
The functional and pharmacological significance of the dopamine D4 receptor (D4R) has remained the least well understood of all the dopamine receptor subtypes. Even more enigmatic has been the role of the very prevalent human DRD4 gene polymorphisms in the region that encodes the third intracellular loop of the receptor. The most common polymorphisms encode a D4R with 4 or 7 repeats of a proline-rich sequence of 16 amino acids (D4.4R and D4.7R). DRD4 polymorphisms have been associated with individual differences linked to impulse control-related neuropsychiatric disorders, with the most consistent associations established between the gene encoding D4.7R and attention-deficit hyperactivity disorder (ADHD) and substance use disorders. The function of D4R and its polymorphic variants is being revealed by addressing the role of receptor heteromerization and the relatively avidity of norepinephrine for D4R. We review the evidence conveying a significant and differential role of D4.4R and D4.7R in the dopaminergic and noradrenergic modulation of the frontal cortico-striatal pyramidal neuron, with implications for the moderation of constructs of impulsivity as personality traits. This differential role depends on their ability to confer different properties to adrenergic α2A receptor (α2AR)-D4R heteromers and dopamine D2 receptor (D2R)-D4R heteromers, preferentially localized in the perisomatic region of the frontal cortical pyramidal neuron and its striatal terminals, respectively. We also review the evidence to support the D4R as a therapeutic target for ADHD and other impulse-control disorders, as well as for restless legs syndrome.
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Affiliation(s)
- Sergi Ferré
- Integrative Neurobiology Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes on Drug Abuse, Baltimore, MD, United States
- *Correspondence: Sergi Ferré,
| | - Annabelle M. Belcher
- Division of Addiction Research and Treatment, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Jordi Bonaventura
- Integrative Neurobiology Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes on Drug Abuse, Baltimore, MD, United States
- Pharmacology Unit, Department of Pathology and Experimental Therapeutics, Faculty of Medicine and Health Sciences, Institute of Neurosciences, University of Barcelona, L'Hospitalet de Llobregat, Spain
- Neuropharmacology & Pain Group, Neuroscience Program, Bellvitge Institute for Biomedical Research, L'Hospitalet de Llobregat, Spain
| | - César Quiroz
- Integrative Neurobiology Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes on Drug Abuse, Baltimore, MD, United States
| | - Marta Sánchez-Soto
- Integrative Neurobiology Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes on Drug Abuse, Baltimore, MD, United States
| | - Verònica Casadó-Anguera
- Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, Institute of Biomedicine of the University of Barcelona (IBUB), University of Barcelona, Barcelona, Spain
| | - Ning-Sheng Cai
- Integrative Neurobiology Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes on Drug Abuse, Baltimore, MD, United States
| | - Estefanía Moreno
- Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, Institute of Biomedicine of the University of Barcelona (IBUB), University of Barcelona, Barcelona, Spain
| | - Comfort A. Boateng
- Department of Basic Pharmaceutical Sciences, Fred Wilson School of Pharmacy, High Point, NC, United States
| | - Thomas M. Keck
- Department of Chemistry and Biochemistry, Rowan University, Glassboro, NJ, United States
| | - Benjamín Florán
- Departament of Physiology, Biophysics and Neurosciences, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico
| | - Christopher J. Earley
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Francisco Ciruela
- Pharmacology Unit, Department of Pathology and Experimental Therapeutics, Faculty of Medicine and Health Sciences, Institute of Neurosciences, University of Barcelona, L'Hospitalet de Llobregat, Spain
- Neuropharmacology & Pain Group, Neuroscience Program, Bellvitge Institute for Biomedical Research, L'Hospitalet de Llobregat, Spain
| | - Vicent Casadó
- Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, Institute of Biomedicine of the University of Barcelona (IBUB), University of Barcelona, Barcelona, Spain
| | - Marcelo Rubinstein
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas and, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Nora D. Volkow
- National Institute on Drug Abuse, National Institutes of Health, Rockville, MD, United States
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Li BX, Jin H, Zhang GJ, Cui LN, Chu CP, Qiu DL. Effect of Noradrenaline on the Facial Stimulation-Evoked Mossy Fiber-Granule Cell Synaptic Transmission in Mouse Cerebellar Cortex. Front Neurosci 2021; 15:785995. [PMID: 34867179 PMCID: PMC8634677 DOI: 10.3389/fnins.2021.785995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 10/13/2021] [Indexed: 11/15/2022] Open
Abstract
Noradrenaline is an important neuromodulator in the cerebellum. We previously found that noradrenaline depressed cerebellar Purkinje cell activity and climbing fiber–Purkinje cell synaptic transmission in vivo in mice. In this study, we investigated the effect of noradrenaline on the facial stimulation-evoked cerebellar cortical mossy fiber–granule cell synaptic transmission in urethane-anesthetized mice. In the presence of a γ-aminobutyrateA (GABAA) receptor antagonist, air-puff stimulation of the ipsilateral whisker pad evoked mossy fiber–granule cell synaptic transmission in the cerebellar granular layer, which expressed stimulus onset response, N1 and stimulus offset response, N2. Cerebellar surface perfusion of 25 μM noradrenaline induced decreases in the amplitude and area under the curve of N1 and N2, accompanied by an increase in the N2/N1 ratio. In the presence of a GABAA receptor blocker, noradrenaline induced a concentration-dependent decrease in the amplitude of N1, with a half-maximal inhibitory concentration of 25.45 μM. The noradrenaline-induced depression of the facial stimulation-evoked mossy fiber–granule cell synaptic transmission was reversed by additional application of an alpha-adrenergic receptor antagonist or an alpha-2 adrenergic receptor antagonist, but not by a beta-adrenergic receptor antagonist or an alpha-1 adrenergic receptor antagonist. Moreover, application of an alpha-2 adrenergic receptor agonist, UK14304, significantly decreased the synaptic response and prevented the noradrenaline-induced depression. Our results indicate that noradrenaline depresses facial stimulation-evoked mossy fiber–granule cell synaptic transmission via the alpha-2 adrenergic receptor in vivo in mice, suggesting that noradrenaline regulates sensory information integration and synaptic transmission in the cerebellar cortical granular layer.
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Affiliation(s)
- Bing-Xue Li
- Brain Science Research Center, Yanbian University, Yanji, China.,Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, China
| | - Hua Jin
- Brain Science Research Center, Yanbian University, Yanji, China.,Department of Psychology, Affiliated Hospital of Yanbian University, Yanji, China
| | - Guang-Jian Zhang
- Brain Science Research Center, Yanbian University, Yanji, China.,Department of Pain, Affiliated Hospital of Yanbian University, Yanji, China
| | - Li-Na Cui
- Brain Science Research Center, Yanbian University, Yanji, China.,Department of Acupuncture, Affiliated Hospital of Yanbian University, Yanji, China
| | - Chun-Ping Chu
- Brain Science Research Center, Yanbian University, Yanji, China.,Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, China
| | - De-Lai Qiu
- Brain Science Research Center, Yanbian University, Yanji, China.,Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, China
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Brocos-Mosquera I, Gabilondo AM, Diez-Alarcia R, Muguruza C, Erdozain AM, Meana JJ, Callado LF. α 2A- and α 2C-adrenoceptor expression and functionality in postmortem prefrontal cortex of schizophrenia subjects. Eur Neuropsychopharmacol 2021; 52:3-11. [PMID: 34237656 DOI: 10.1016/j.euroneuro.2021.05.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 04/28/2021] [Accepted: 05/26/2021] [Indexed: 12/25/2022]
Abstract
Previous evidence suggests that α2-adrenoceptors (α2-AR) may be involved in the pathophysiology of schizophrenia. However, postmortem brain studies on α2-AR expression and functionality in schizophrenia are scarce. The aim of our work was to evaluate α2A-AR and α2C-AR expression in different subcellular fractions of prefrontal cortex postmortem tissue from antipsychotic-free (absence of antipsychotics in blood at the time of death) (n = 12) and antipsychotic-treated (n = 12) subjects with schizophrenia, and matched controls (n = 24). Functional coupling of α2-AR to Gα proteins induced by the agonist UK14304 was also tested. Additionally, Gα protein expression was also evaluated. In antipsychotic-free schizophrenia subjects, α2A-AR and α2C-AR protein expression was similar to controls in all the subcellular fractions. Conversely, in antipsychotic-treated schizophrenia subjects, increased α2A-AR expression was found in synaptosomal plasma membrane and postsynaptic density (PSD) fractions (+60% and +79% vs controls, respectively) with no significant changes in α2C-AR. [35S]GTPγS SPA experiments showed a significant lower stimulation of Gαi2 and Gαi3 proteins by UK14304 in antipsychotic-treated schizophrenia subjects, whereas stimulation in antipsychotic-free schizophrenia subjects remained unchanged. Gαo protein stimulation was significantly decreased in both antipsychotic-free and antipsychotic-treated schizophrenia subjects compared to controls. Expression of Gαi3 protein did not differ between groups, whereas Gαi2 levels were increased in PSD of schizophrenia subjects, both antipsychotic-free and antipsychotic-treated. Gαo protein expression was increased in PSD of antipsychotic-treated subjects and in the presynaptic fraction of antipsychotic-free schizophrenia subjects. The present results suggest that antipsychotic treatment is able to modify in opposite directions both the protein expression and the functionality of α2A-AR in the cortex of schizophrenia patients.
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Affiliation(s)
- Iria Brocos-Mosquera
- Department of Pharmacology, University of the Basque Country, UPV/EHU, Leioa, Bizkaia, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Spain
| | - Ane M Gabilondo
- Department of Pharmacology, University of the Basque Country, UPV/EHU, Leioa, Bizkaia, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Spain; Biocruces Bizkaia Health Research Institute, Barakaldo, Bizkaia, Spain
| | - Rebeca Diez-Alarcia
- Department of Pharmacology, University of the Basque Country, UPV/EHU, Leioa, Bizkaia, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Spain; Biocruces Bizkaia Health Research Institute, Barakaldo, Bizkaia, Spain
| | - Carolina Muguruza
- Department of Pharmacology, University of the Basque Country, UPV/EHU, Leioa, Bizkaia, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Spain
| | - Amaia M Erdozain
- Department of Pharmacology, University of the Basque Country, UPV/EHU, Leioa, Bizkaia, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Spain
| | - J Javier Meana
- Department of Pharmacology, University of the Basque Country, UPV/EHU, Leioa, Bizkaia, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Spain; Biocruces Bizkaia Health Research Institute, Barakaldo, Bizkaia, Spain
| | - Luis F Callado
- Department of Pharmacology, University of the Basque Country, UPV/EHU, Leioa, Bizkaia, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Spain; Biocruces Bizkaia Health Research Institute, Barakaldo, Bizkaia, Spain.
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van Stralen J, Gill SK, Reaume CJ, Handelman K. A retrospective medical chart review of clinical outcomes in children and adolescents with attention-deficit/hyperactivity disorder treated with guanfacine extended-release in routine Canadian clinical practice. Child Adolesc Psychiatry Ment Health 2021; 15:55. [PMID: 34607580 PMCID: PMC8491395 DOI: 10.1186/s13034-021-00402-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Accepted: 09/03/2021] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE This study evaluated clinical outcomes in children and adolescents with attention-deficit/hyperactivity disorder (ADHD) treated with the α2-adrenoceptor agonist guanfacine extended-release (GXR) in routine Canadian clinical practice. METHODS This retrospective chart review focused on patients with ADHD aged 6-17 years initiating treatment with GXR as monotherapy or adjunctive therapy. Patients were followed for up to 12 months after GXR initiation and, if they had received prior ADHD pharmacotherapy, for 12 months before GXR initiation. The primary outcome was change in ADHD symptoms and functionality based on physician assessments, classified as improvement, no change, or worsening relative to the time of GXR initiation. Treatment-emergent adverse events (TEAEs) were evaluated. Clinical outcomes were also analyzed post hoc according to whether GXR treatment was received as monotherapy or adjunctive therapy, and by select psychiatric comorbidities. Exploratory analyses were conducted in patients who had received prior ADHD pharmacotherapy to evaluate clinical outcomes after initiating GXR. RESULTS Improvements in ADHD symptoms were reported for 232/330 (70.3%) patients. Functional improvements in school performance and home life were reported for 213/330 (64.5%) and 209/330 (63.3%) patients, respectively. The most frequent TEAEs (≥ 5%) were somnolence, headache, insomnia, presyncope, and decreased appetite. Improvements in ADHD symptoms were observed when GXR was received as either monotherapy (35/60 [58.3%]) or adjunctive therapy (197/270 [73.0%]). Improvements in ADHD symptoms and functionality were observed in the majority of patients with select psychiatric comorbidities. Among patients who had experienced worsening of symptoms with prior ADHD pharmacotherapy, 44/54 (81.5%) experienced symptom improvement, 33/44 (75.0%) who had previously experienced worsening of school performance improved, and 34/48 (70.8%) who had previously experienced worsening of home life improved. CONCLUSION In Canadian routine clinical practice, most children and adolescents with ADHD treated with GXR experienced improvements in ADHD symptoms and in functionality both at school and at home.
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Affiliation(s)
- Judy van Stralen
- Center for Pediatric Excellence, 206-1637 Woodroffe Avenue, Ottawa, ON, K2G 1W2, Canada.
| | - Simerpal K. Gill
- grid.507459.a0000 0004 0436 0978Takeda Canada Inc., Toronto, ON Canada
| | - Christopher J. Reaume
- grid.507459.a0000 0004 0436 0978Shire Pharma Canada ULC, A Takeda Company (Now Takeda Canada Inc.), Toronto, ON Canada
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9
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Ahmadirad N, Fathollahi Y, Janahmadi M, Ghasemi Z, Shojaei A, Rezaei M, Barkley V, Mirnajafi-Zadeh J. The role of α adrenergic receptors in mediating the inhibitory effect of electrical brain stimulation on epileptiform activity in rat hippocampal slices. Brain Res 2021; 1765:147492. [PMID: 33887250 DOI: 10.1016/j.brainres.2021.147492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 04/06/2021] [Accepted: 04/14/2021] [Indexed: 10/21/2022]
Abstract
The Inhibitory effect of electrical low-frequency stimulation (LFS) on neuronal excitability and seizure occurrence has been indicated in experimental models, but the precise mechanism has not established. This investigation was intended to figure out the role of α1 and α2 adrenergic receptors in LFS' inhibitory effect on neuronal excitability. Epileptiform activity induced in an in vitro rat hippocampal slice preparation by high K+ ACSF and LFS (900 square wave pulses at 1 Hz) was administered at the beginning of epileptiform activity to the Schaffer collaterals. In CA1 pyramidal neurons, the electrophysiological properties were measured at the baseline, before high K+ ACSF washout, and at 15 min after high K+ ACSF washout using whole-cell, patch-clamp recording. Results indicated that after high K+ ACSF washout, prazosine (10 µM; α1 adrenergic receptor antagonist) and yohimbine (5 µM; α2 adrenergic receptor antagonist) suppressed the LFS' effect of reducing rheobase current and utilization time following depolarizing ramp current, the latency to the first spike following a depolarizing current and latency to the first rebound action potential following hyperpolarizing current pulses. Thus, it may be proposed that LFS' inhibitory action on the neuronal hyperexcitability, in some way, is mediated by α1 and α2 adrenergic receptors.
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Affiliation(s)
- Nooshin Ahmadirad
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Yaghoub Fathollahi
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Mahyar Janahmadi
- Department of Physiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Zahra Ghasemi
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada
| | - Amir Shojaei
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Mahmoud Rezaei
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Victoria Barkley
- Krembil Research Institute, University Health Network, Toronto, Canada
| | - Javad Mirnajafi-Zadeh
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran; Institute for Brain Sciences and Cognition, Tarbiat Modares University, Tehran, Iran.
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10
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Cui LN, Sun N, Li BX, Wang LF, Zhang XY, Qiu DL, Chu CP. Noradrenaline inhibits complex spikes activity via the presynaptic PKA signaling pathway in mouse cerebellar slices. Neurosci Lett 2020; 729:135008. [PMID: 32344107 DOI: 10.1016/j.neulet.2020.135008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/10/2020] [Accepted: 04/20/2020] [Indexed: 10/24/2022]
Abstract
Norepinephrine (NA) is an important neurotransmitter of the cerebellum that regulates synaptic transmission, motor regulation and motor learning under certain conditions via adrenergic receptors (ARs). We previously found that NA depressed cerebellar climbing fiber-Purkinje cell (CF-PC) synaptic transmission via α2-ARs in vivo in mice. We here investigated the mechanisms of NA inhibited CF-PC synaptic transmission in acute cerebellar slices using the whole-cell recording technique and pharmacological methods. Bath application of NA (10 μM) depressed CF-PC synaptic transmission, which exhibited a time-dependent decrease in amplitude of excitatory postsynaptic currents (N1), accompanied by an increase in the paired-pulse ratio (PPR). The NA-induced depression of CF-PC synaptic transmission was significantly prevented by inhibition of protein kinase A (PKA) with either H-89 or KT5720. Furthermore, the NA-induced inhibition of CF-PC synaptic transmission was rescued by activation adenylate cyclase (AC), and the AC-induced enhancement of CF-PC synaptic transmission was depressed by NA. Moreover, inhibition of AC with SQ22536, produced a significant depression of CF-PC synaptic transmission and abrogated the NA-induced depression of CF-PC synaptic transmission. However, the NA-induced depression of CF-PC synaptic transmission was not blocked by intracellular inhibition of PKA with a cell impermeable PKA inhibitor, PKI, or by extracellular inhibition of protein kinase C. These results indicate that NA activates presynaptic α2-AR, resulting in a depression of mouse cerebellar CF-PC synaptic transmission through the AC-PKA signaling pathway.
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Affiliation(s)
- Li-Na Cui
- Brain Science Research Center, Yanbian University, Yanji, China; Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, China; Department of Acupuncture, Affiliated Hospital of Yanbian University, Yanji, Jilin, China
| | - Na Sun
- Brain Science Research Center, Yanbian University, Yanji, China; Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, China
| | - Bing-Xue Li
- Brain Science Research Center, Yanbian University, Yanji, China; Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, China
| | - Li-Fei Wang
- Brain Science Research Center, Yanbian University, Yanji, China; Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, China
| | - Xin-Yuan Zhang
- Brain Science Research Center, Yanbian University, Yanji, China; Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, China
| | - De-Lai Qiu
- Brain Science Research Center, Yanbian University, Yanji, China; Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, China.
| | - Chun-Ping Chu
- Brain Science Research Center, Yanbian University, Yanji, China; Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, China.
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11
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Chronic Stress Induces Maladaptive Behaviors by Activating Corticotropin-Releasing Hormone Signaling in the Mouse Oval Bed Nucleus of the Stria Terminalis. J Neurosci 2020; 40:2519-2537. [PMID: 32054675 DOI: 10.1523/jneurosci.2410-19.2020] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 01/16/2020] [Accepted: 01/16/2020] [Indexed: 12/21/2022] Open
Abstract
The bed nucleus of the stria terminalis (BNST) is a forebrain region highly responsive to stress that expresses corticotropin-releasing hormone (CRH) and is implicated in mood disorders, such as anxiety. However, the exact mechanism by which chronic stress induces CRH-mediated dysfunction in BNST and maladaptive behaviors remains unclear. Here, we first confirmed that selective acute optogenetic activation of the oval nucleus BNST (ovBNST) increases maladaptive avoidance behaviors in male mice. Next, we found that a 6 week chronic variable mild stress (CVMS) paradigm resulted in maladaptive behaviors and increased cellular excitability of ovBNST CRH neurons by potentiating mEPSC amplitude, altering the resting membrane potential, and diminishing M-currents (a voltage-gated K+ current that stabilizes membrane potential) in ex vivo slices. CVMS also increased c-fos+ cells in ovBNST following handling. We next investigated potential molecular mechanism underlying the electrophysiological effects and observed that CVMS increased CRH+ and pituitary adenylate cyclase-activating polypeptide+ (PACAP; a CRH upstream regulator) cells but decreased striatal-enriched protein tyrosine phosphatase+ (a STEP CRH inhibitor) cells in ovBNST. Interestingly, the electrophysiological effects of CVMS were reversed by CRHR1-selective antagonist R121919 application. CVMS also activated protein kinase A (PKA) in BNST, and chronic infusion of the PKA-selective antagonist H89 into ovBNST reversed the effects of CVMS. Coadministration of the PKA agonist forskolin prevented the beneficial effects of R121919. Finally, CVMS induced an increase in surface expression of phosphorylated GluR1 (S845) in BNST. Collectively, these findings highlight a novel and indispensable stress-induced role for PKA-dependent CRHR1 signaling in activating BNST CRH neurons and mediating maladaptive behaviors.SIGNIFICANCE STATEMENT Chronic stress and acute activation of oval bed nucleus of the stria terminalis (ovBNST) induces maladaptive behaviors in rodents. However, the precise molecular and electrophysiological mechanisms underlying these effects remain unclear. Here, we demonstrate that chronic variable mild stress activates corticotropin-releasing hormone (CRH)-associated stress signaling and CRH neurons in ovBNST by potentiating mEPSC amplitude and decreasing M-current in male mice. These electrophysiological alterations and maladaptive behaviors were mediated by BNST protein kinase A-dependent CRHR1 signaling. Our results thus highlight the importance of BNST CRH dysfunction in chronic stress-induced disorders.
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12
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Cong Z, Li D, Tao Y, Lv X, Zhu X. α 2A -AR antagonism by BRL-44408 maleate attenuates acute lung injury in rats with downregulation of ERK1/2, p38MAPK, and p65 pathway. J Cell Physiol 2020; 235:6905-6914. [PMID: 32003020 DOI: 10.1002/jcp.29586] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 01/13/2020] [Indexed: 12/17/2022]
Abstract
Acute respiratory distress syndrome (ARDS), characterized by acute hypoxic respiratory dysfunction or failure, is a manifestation of multiple organ failure in the lung, and the most common risk factor is sepsis. We previously showed that blocking α2 -adrenoceptor (α2 -AR) could attenuate lung injury induced by endotoxin in rats. α2A -adrenoceptor (α2A -AR), a subtype of α2 -AR plays a key role in inflammatory diseases, but the mechanism remains unknown. Here, we explored the effect of BRL-44408 maleate (BRL), a specific α2A -AR antagonist, on cecal ligation puncture (CLP)-induced ARDS in rats and the underlying mechanism. Preadministration of BRL-44408 maleate significantly alleviated CLP-induced histological injury, macrophage infiltration, inflammatory response, and wet/dry ratio in lung tissue. However, there was no statistical difference in survival rate between the CLP and CLP+BRL groups. Extracellular regulated protein kinase (ERK1/2), p38MAPK, and p65 were activated in the CLP group, and BRL-44408 maleate inhibited the activation of these signal molecules, c-Jun N-terminal kinase (JNK) and protein kinase A (PKA) showed no changes in activation between these two groups. BRL-44408 maleate decreased lipopolysaccharide (LPS)-induced expression of cytokines in NR8383 rat alveolar macrophages and reduced phosphorylation of ERK1/2, p38MAPK, and p65. JNK and PKA were not influenced by LPS. Together, these findings suggest that antagonism of α2A -AR improves CLP-induced acute lung injury and involves the downregulation of ERK1/2, p38MAPK, and p65 pathway independent of the activation of JNK and PKA.
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Affiliation(s)
- Zhukai Cong
- Department of Critical Care Medicine, Peking University Third Hospital, Beijing, China
| | - Dan Li
- Department of Critical Care Medicine, Peking University Third Hospital, Beijing, China
| | - Yifan Tao
- Department of Anesthesiology, Peking University Third Hospital, Beijing, China
| | - Xiangpeng Lv
- Department of Critical Care Medicine, Peking University Third Hospital, Beijing, China
| | - Xi Zhu
- Department of Critical Care Medicine, Peking University Third Hospital, Beijing, China
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13
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Liu S, Miersch S, Li P, Bai B, Liu C, Qin W, Su J, Huang H, Pan J, Sidhu SS, Wu D. A Synthetic Human Antibody Antagonizes IL-18Rβ Signaling Through an Allosteric Mechanism. J Mol Biol 2020; 432:1169-1182. [PMID: 31954129 DOI: 10.1016/j.jmb.2020.01.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 01/07/2020] [Accepted: 01/08/2020] [Indexed: 01/01/2023]
Abstract
The interleukin-18 subfamily belongs to the interleukin-1 family and plays an important role in modulating innate and adaptive immune responses. Dysregulation of IL-18 has been implicated in or correlated with numerous diseases, including inflammatory diseases, autoimmune disorders, and cancer. Thus, blockade of IL-18 signaling may offer therapeutic benefits in many pathological settings. Here, we report the development of synthetic human antibodies that target human IL-18Rβ and block IL-18-mediated IFN-γ secretion by inhibiting NF-κB and MAPK dependent pathways. The crystal structure of a potent antagonist antibody in complex with IL-18Rβ revealed inhibition through an unexpected allosteric mechanism. Our findings offer a novel means for therapeutic intervention in the IL-18 pathway and may provide a new strategy for targeting cytokine receptors.
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Affiliation(s)
- Shusu Liu
- Laboratory of Antibody Engineering, Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China
| | - Shane Miersch
- Banting and Best Department of Medical Research, Terrence Donnelly Center for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, Canada
| | - Ping Li
- Laboratory of Antibody Engineering, Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China; Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, China
| | - Bingxin Bai
- Laboratory of Antibody Engineering, Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China
| | - Chunchun Liu
- Laboratory of Antibody Engineering, Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China
| | - Wenming Qin
- National Facility for Protein Science (Shanghai), Shanghai Advanced Research Institute (Zhangjiang Lab), Chinese Academy of Sciences, Shanghai, China
| | - Jie Su
- Laboratory of Antibody Engineering, Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China
| | - Haiming Huang
- Banting and Best Department of Medical Research, Terrence Donnelly Center for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, Canada; Shanghai Asian United Antibody Medical Co., Shanghai, China
| | - James Pan
- Banting and Best Department of Medical Research, Terrence Donnelly Center for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, Canada
| | - Sachdev S Sidhu
- Laboratory of Antibody Engineering, Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China; Banting and Best Department of Medical Research, Terrence Donnelly Center for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, Canada.
| | - Donghui Wu
- Laboratory of Antibody Engineering, Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China.
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14
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Erdozain AM, Brocos-Mosquera I, Gabilondo AM, Meana JJ, Callado LF. Differential α 2A- and α 2C-adrenoceptor protein expression in presynaptic and postsynaptic density fractions of postmortem human prefrontal cortex. J Psychopharmacol 2019; 33:244-249. [PMID: 30255728 DOI: 10.1177/0269881118798612] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Three different α2-adrenoceptor (α2-AR) subtypes have been described. The α2A-AR and α2C-AR subtypes are highly expressed in the human prefrontal cortex, where they modulate neurotransmission. However, due to the lack of subtype-selective ligands, the physiological relevance of both subtypes has not been fully resolved. AIMS In this context, the aim of the present study was to characterize the protein expression of both α2-AR subtypes, in different synaptic fractions of postmortem human prefrontal cortex. METHODS A subcellular fractionation of the samples was performed and the protein expression of α2A- and α2C-ARs was measured in presynaptic membranes and postsynaptic density fractions by Western blot. RESULTS The results revealed that the α2A-AR subtype is mainly located postsynaptically (95±3%) whereas the remaining 5±3% is in the presynapse. Conversely, the α2C-AR subtype showed a similar distribution between pre- and postsynaptic membranes, with a slightly higher percentage present in the presynapse (60±2% vs. 40±2%). CONCLUSIONS These findings could explain some contradictory effects reported for α2-AR agonists and antagonists in the human prefrontal cortex. Furthermore, the present data could contribute to elucidating the therapeutic potential of selectively targeting α2A- or α2C-AR subtypes.
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Affiliation(s)
- Amaia M Erdozain
- 1 Department of Pharmacology, University of the Basque Country, UPV/EHU, Leioa, Spain.,2 Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Spain
| | - Iria Brocos-Mosquera
- 1 Department of Pharmacology, University of the Basque Country, UPV/EHU, Leioa, Spain
| | - Ane M Gabilondo
- 1 Department of Pharmacology, University of the Basque Country, UPV/EHU, Leioa, Spain.,2 Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Spain.,3 Biocruces Health Research Institute, Barakaldo, Spain
| | - J Javier Meana
- 1 Department of Pharmacology, University of the Basque Country, UPV/EHU, Leioa, Spain.,2 Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Spain.,3 Biocruces Health Research Institute, Barakaldo, Spain
| | - Luis F Callado
- 1 Department of Pharmacology, University of the Basque Country, UPV/EHU, Leioa, Spain.,2 Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Spain.,3 Biocruces Health Research Institute, Barakaldo, Spain
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15
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Grzelka K, Kurowski P, Gawlak M, Szulczyk P. Noradrenaline Modulates the Membrane Potential and Holding Current of Medial Prefrontal Cortex Pyramidal Neurons via β 1-Adrenergic Receptors and HCN Channels. Front Cell Neurosci 2017; 11:341. [PMID: 29209170 PMCID: PMC5701640 DOI: 10.3389/fncel.2017.00341] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 10/16/2017] [Indexed: 12/27/2022] Open
Abstract
The medial prefrontal cortex (mPFC) receives dense noradrenergic projections from the locus coeruleus. Adrenergic innervation of mPFC pyramidal neurons plays an essential role in both physiology (control of memory formation, attention, working memory, and cognitive behavior) and pathophysiology (attention deficit hyperactivity disorder, posttraumatic stress disorder, cognitive deterioration after traumatic brain injury, behavioral changes related to addiction, Alzheimer's disease and depression). The aim of this study was to elucidate the mechanism responsible for adrenergic receptor-mediated control of the resting membrane potential in layer V mPFC pyramidal neurons. The membrane potential or holding current of synaptically isolated layer V mPFC pyramidal neurons was recorded in perforated-patch and classical whole-cell configurations in slices from young rats. Application of noradrenaline (NA), a neurotransmitter with affinity for all types of adrenergic receptors, evoked depolarization or inward current in the tested neurons irrespective of whether the recordings were performed in the perforated-patch or classical whole-cell configuration. The effect of noradrenaline depended on β1- and not α1- or α2-adrenergic receptor stimulation. Activation of β1-adrenergic receptors led to an increase in inward Na+ current through hyperpolarization-activated cyclic nucleotide-gated (HCN) channels, which carry a mixed Na+/K+ current. The protein kinase A- and C-, glycogen synthase kinase-3β- and tyrosine kinase-linked signaling pathways were not involved in the signal transduction between β1-adrenergic receptors and HCN channels. The transduction system operated in a membrane-delimited fashion and involved the βγ subunit of G-protein. Thus, noradrenaline controls the resting membrane potential and holding current in mPFC pyramidal neurons through β1-adrenergic receptors, which in turn activate HCN channels via a signaling pathway involving the βγ subunit.
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Affiliation(s)
- Katarzyna Grzelka
- Laboratory of Physiology and Pathophysiology, Centre for Preclinical Research and Technology, Medical University of Warsaw, Warsaw, Poland
| | | | | | - Paweł Szulczyk
- Laboratory of Physiology and Pathophysiology, Centre for Preclinical Research and Technology, Medical University of Warsaw, Warsaw, Poland
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16
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Hassani SA, Oemisch M, Balcarras M, Westendorff S, Ardid S, van der Meer MA, Tiesinga P, Womelsdorf T. A computational psychiatry approach identifies how alpha-2A noradrenergic agonist Guanfacine affects feature-based reinforcement learning in the macaque. Sci Rep 2017; 7:40606. [PMID: 28091572 PMCID: PMC5238510 DOI: 10.1038/srep40606] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 12/08/2016] [Indexed: 01/05/2023] Open
Abstract
Noradrenaline is believed to support cognitive flexibility through the alpha 2A noradrenergic receptor (a2A-NAR) acting in prefrontal cortex. Enhanced flexibility has been inferred from improved working memory with the a2A-NA agonist Guanfacine. But it has been unclear whether Guanfacine improves specific attention and learning mechanisms beyond working memory, and whether the drug effects can be formalized computationally to allow single subject predictions. We tested and confirmed these suggestions in a case study with a healthy nonhuman primate performing a feature-based reversal learning task evaluating performance using Bayesian and Reinforcement learning models. In an initial dose-testing phase we found a Guanfacine dose that increased performance accuracy, decreased distractibility and improved learning. In a second experimental phase using only that dose we examined the faster feature-based reversal learning with Guanfacine with single-subject computational modeling. Parameter estimation suggested that improved learning is not accounted for by varying a single reinforcement learning mechanism, but by changing the set of parameter values to higher learning rates and stronger suppression of non-chosen over chosen feature information. These findings provide an important starting point for developing nonhuman primate models to discern the synaptic mechanisms of attention and learning functions within the context of a computational neuropsychiatry framework.
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Affiliation(s)
- S. A. Hassani
- Department of Biology, Centre for Vision Research, York University, Toronto, Ontario M6J 1P3, Canada
| | - M. Oemisch
- Department of Biology, Centre for Vision Research, York University, Toronto, Ontario M6J 1P3, Canada
| | - M. Balcarras
- Department of Biology, Centre for Vision Research, York University, Toronto, Ontario M6J 1P3, Canada
| | - S. Westendorff
- Department of Biology, Centre for Vision Research, York University, Toronto, Ontario M6J 1P3, Canada
| | - S. Ardid
- Department of Mathematics, Boston University, Boston, MA 02215, USA
| | - M. A. van der Meer
- Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH 03755, USA
| | - P. Tiesinga
- Department of Neuroinformatics, Donders Centre for Neuroscience, Radboud University Nijmegen, Nijmegen, AJ 6525, The Netherlands
| | - T. Womelsdorf
- Department of Biology, Centre for Vision Research, York University, Toronto, Ontario M6J 1P3, Canada
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Hoxha E, Tempia F, Lippiello P, Miniaci MC. Modulation, Plasticity and Pathophysiology of the Parallel Fiber-Purkinje Cell Synapse. Front Synaptic Neurosci 2016; 8:35. [PMID: 27857688 PMCID: PMC5093118 DOI: 10.3389/fnsyn.2016.00035] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Accepted: 10/19/2016] [Indexed: 12/24/2022] Open
Abstract
The parallel fiber-Purkinje cell (PF-PC) synapse represents the point of maximal signal divergence in the cerebellar cortex with an estimated number of about 60 billion synaptic contacts in the rat and 100,000 billions in humans. At the same time, the Purkinje cell dendritic tree is a site of remarkable convergence of more than 100,000 parallel fiber synapses. Parallel fiber activity generates fast postsynaptic currents via α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, and slower signals, mediated by mGlu1 receptors, resulting in Purkinje cell depolarization accompanied by sharp calcium elevation within dendritic regions. Long-term depression (LTD) and long-term potentiation (LTP) have been widely described for the PF-PC synapse and have been proposed as mechanisms for motor learning. The mechanisms of induction for LTP and LTD involve different signaling mechanisms within the presynaptic terminal and/or at the postsynaptic site, promoting enduring modification in the neurotransmitter release and change in responsiveness to the neurotransmitter. The PF-PC synapse is finely modulated by several neurotransmitters, including serotonin, noradrenaline and acetylcholine. The ability of these neuromodulators to gate LTP and LTD at the PF-PC synapse could, at least in part, explain their effect on cerebellar-dependent learning and memory paradigms. Overall, these findings have important implications for understanding the cerebellar involvement in a series of pathological conditions, ranging from ataxia to autism. For example, PF-PC synapse dysfunctions have been identified in several murine models of spino-cerebellar ataxia (SCA) types 1, 3, 5 and 27. In some cases, the defect is specific for the AMPA receptor signaling (SCA27), while in others the mGlu1 pathway is affected (SCA1, 3, 5). Interestingly, the PF-PC synapse has been shown to be hyper-functional in a mutant mouse model of autism spectrum disorder, with a selective deletion of Pten in Purkinje cells. However, the full range of methodological approaches, that allowed the discovery of the physiological principles of PF-PC synapse function, has not yet been completely exploited to investigate the pathophysiological mechanisms of diseases involving the cerebellum. We, therefore, propose to extend the spectrum of experimental investigations to tackle this problem.
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Affiliation(s)
- Eriola Hoxha
- Neuroscience Institute Cavalieri Ottolenghi (NICO) and Department of Neuroscience, University of TorinoTorino, Italy
| | - Filippo Tempia
- Neuroscience Institute Cavalieri Ottolenghi (NICO) and Department of Neuroscience, University of TorinoTorino, Italy
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Arnsten AFT, Wang M. Targeting Prefrontal Cortical Systems for Drug Development: Potential Therapies for Cognitive Disorders. Annu Rev Pharmacol Toxicol 2016; 56:339-60. [PMID: 26738476 DOI: 10.1146/annurev-pharmtox-010715-103617] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Medications to treat cognitive disorders are increasingly needed, yet researchers have had few successes in this challenging arena. Cognitive abilities in primates arise from highly evolved N-methyl-d-aspartate (NMDA) receptor circuits in layer III of the dorsolateral prefrontal cortex. These circuits have unique modulatory needs that can differ from the layer V neurons that predominate in rodents, but they offer multiple therapeutic targets. Cognitive improvement often requires low doses that enhance the pattern of information held in working memory, whereas higher doses can produce nonspecific changes that obscure information. Identifying appropriate doses for clinical trials may be helped by assessments in monkeys and by flexible, individualized dose designs. The use of guanfacine (Intuniv) for prefrontal cortical disorders was based on research in monkeys, supporting this approach. Coupling our knowledge of higher primate circuits with the powerful methods now available in drug design will help create effective treatments for cognitive disorders.
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Affiliation(s)
- Amy F T Arnsten
- Department of Neurobiology, Yale University School of Medicine, New Haven, Connecticut 06510; ,
| | - Min Wang
- Department of Neurobiology, Yale University School of Medicine, New Haven, Connecticut 06510; ,
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Abstract
Children/adolescents with attention-deficit/hyperactivity disorder (ADHD) may have a poor or inadequate response to psychostimulants or be unable to tolerate their side-effects; furthermore, stimulants may be inappropriate because of co-existing conditions. Only one non-stimulant ADHD pharmacotherapy, the noradrenaline transporter inhibitor atomoxetine, is currently approved for use in Europe. We review recent advances in understanding of the pathophysiology of ADHD with a focus on the roles of catecholamine receptors in context of the α2A-adrenergic receptor agonist guanfacine extended release (GXR), a new non-stimulant treatment option in Europe. Neuroimaging studies of children/adolescents with ADHD show impaired brain maturation, and structural and functional anomalies in brain regions and networks. Neurobiological studies in ADHD and medication response patterns support involvement of monoaminergic neurotransmitters (primarily dopamine and noradrenaline). Guanfacine is a selective α2A-adrenergic receptor agonist that has been shown to improve prefrontal cortical cognitive function, including working memory. The hypothesized mode of action of guanfacine centres on direct stimulation of post-synaptic α2A-adrenergic receptors to enhance noradrenaline neurotransmission. Preclinical data suggest that guanfacine also influences dendritic spine growth and maturation. Clinical trials have demonstrated the efficacy of GXR in ADHD, and it is approved as monotherapy or adjunctive therapy to stimulants in Canada and the USA (for children and adolescents). GXR was approved recently in Europe for the treatment of ADHD in children and adolescents for whom stimulants are not suitable, not tolerated or have been shown to be ineffective. GXR may provide particular benefit for children/adolescents who have specific co-morbidities such as chronic tic disorders or oppositional defiant disorder (or oppositional symptoms) that have failed to respond to first-line treatment options.
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Norepinephrine versus dopamine and their interaction in modulating synaptic function in the prefrontal cortex. Brain Res 2016; 1641:217-33. [PMID: 26790349 DOI: 10.1016/j.brainres.2016.01.005] [Citation(s) in RCA: 109] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 12/16/2015] [Accepted: 01/05/2016] [Indexed: 01/11/2023]
Abstract
Among the neuromodulators that regulate prefrontal cortical circuit function, the catecholamine transmitters norepinephrine (NE) and dopamine (DA) stand out as powerful players in working memory and attention. Perturbation of either NE or DA signaling is implicated in the pathogenesis of several neuropsychiatric disorders, including attention deficit hyperactivity disorder (ADHD), post-traumatic stress disorder (PTSD), schizophrenia, and drug addiction. Although the precise mechanisms employed by NE and DA to cooperatively control prefrontal functions are not fully understood, emerging research indicates that both transmitters regulate electrical and biochemical aspects of neuronal function by modulating convergent ionic and synaptic signaling in the prefrontal cortex (PFC). This review summarizes previous studies that investigated the effects of both NE and DA on excitatory and inhibitory transmissions in the prefrontal cortical circuitry. Specifically, we focus on the functional interaction between NE and DA in prefrontal cortical local circuitry, synaptic integration, signaling pathways, and receptor properties. Although it is clear that both NE and DA innervate the PFC extensively and modulate synaptic function by activating distinctly different receptor subtypes and signaling pathways, it remains unclear how these two systems coordinate their actions to optimize PFC function for appropriate behavior. Throughout this review, we provide perspectives and highlight several critical topics for future studies. This article is part of a Special Issue entitled SI: Noradrenergic System.
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Luo F, Tang H, Cheng ZY. Stimulation of α1-adrenoceptors facilitates GABAergic transmission onto pyramidal neurons in the medial prefrontal cortex. Neuroscience 2015; 300:63-74. [PMID: 25943480 DOI: 10.1016/j.neuroscience.2015.04.070] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 04/27/2015] [Accepted: 04/28/2015] [Indexed: 11/16/2022]
Abstract
Whereas activation of α1-adrenoceptors (α1-ARs) modulates glutamatergic transmission, the roles of α1-ARs in GABAergic transmission in the medial prefrontal cortex (mPFC) are elusive. Here, we examined the effects of the α1-AR agonist phenylephrine (Phe) on GABAergic transmission onto pyramidal neurons in the deep layers of the mPFC. We found that bath application of Phe dose-dependently increased the amplitude of evoked IPSCs (eIPSCs). Phe increased the frequency but not the amplitude of miniature IPSCs (mIPSCs). Ca(2+) influx through T-type voltage-gated calcium channels is required for Phe-induced increases in GABA release. Phe increases GABA release probability and the number of releasable vesicles. Phe depolarizes the fast-spiking (FS) interneurons without effects on the firing rate of action potentials (APs) of interneurons. Phe-induced depolarization is independent of extracellular Na(+), Ca(2+) and T-type calcium channels, but requires inward rectifier K(+) channels (Kirs). The present study demonstrates that Phe enhances GABAergic transmission onto mPFC pyramidal neurons through inhibiting interneurons Kirs, which further depolarizes interneurons leading to increase in Ca(2+) influx via T-type calcium channels. Our results may provide a cellular and molecular mechanism that helps explain α1-AR-induced PFC dysfunction.
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Affiliation(s)
- F Luo
- Center for Neuropsychiatric Diseases, Institute of Life Science, Nanchang University, Nanchang 330031, China.
| | - H Tang
- Center for Neuropsychiatric Diseases, Institute of Life Science, Nanchang University, Nanchang 330031, China
| | - Z-Y Cheng
- Center for Neuropsychiatric Diseases, Institute of Life Science, Nanchang University, Nanchang 330031, China
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García-Fuster MJ, García-Sevilla JA. Monoamine receptor agonists, acting preferentially at presynaptic autoreceptors and heteroreceptors, downregulate the cell fate adaptor FADD in rat brain cortex. Neuropharmacology 2014; 89:204-14. [PMID: 25286119 DOI: 10.1016/j.neuropharm.2014.09.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 08/26/2014] [Accepted: 09/15/2014] [Indexed: 11/13/2022]
Abstract
FADD is a crucial adaptor of death receptors that can engage apoptosis or survival actions (e.g. neuroplasticity) through its phosphorylated form (p-FADD). Although FADD was shown to participate in receptor mechanisms related to drugs of abuse, little is known on its role in the signaling of classic neurotransmitters (dopamine, noradrenaline, and serotonin) in brain. This study assessed the modulation of FADD (and p-FADD/FADD ratio, as an index of neuroplasticity) and FLIP-L (a neuroprotective FADD interacting partner), as well as the role of MEK-ERK signaling, after activation of monoamine auto/heteroreceptors by selective agonists in rat cortex. Acute depletion of monoamines with reserpine, but not with AMPT or PCPA, reduced FADD (28%) and increased p-FADD/FADD ratio (1.34-fold). Activation of presynaptic α2A-adrenoceptors (UK-14304 and clonidine), 5-HT1A receptors (8-OH-DPAT), and D2 dopamine receptor (bromocriptine) dose-dependently decreased FADD (up to 54%) and increased p-FADD (up to 29%) and p-FADD/FADD ratios (up to 2.93-fold), through specific receptor mechanisms. Activation of rat 5-HT1B autoreceptor in axon terminals by CP-94253 did not modulate FADD forms. Activation of postsynaptic D1 dopamine receptor by SKF-81297 also reduced FADD (25%) and increased p-FADD (32%). Disruption of MEK-ERK activation with SL327 did not modify clonidine (α2A-adrenoceptor)-induced FADD inhibition, indicating that agonist effect was not dependent on ERK signaling. The various monoamine receptor agonists and antagonists did not alter FLIP-L content, or the activation of executioner caspase-3 and PARP-1 cleavage, indicating that the agonists attenuated apoptotic signals and promoted neuroplasticity through FADD regulation. These novel results indicate that inhibition of pro-apoptotic FADD adaptor could function as a common signaling step in the initial activation of monoamine receptors in the brain.
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Affiliation(s)
- M Julia García-Fuster
- Neurobiology of Drug Abuse Group, IUNICS/IdISPa, University of the Balearic Islands, Spain; Redes Temáticas de Investigación Cooperativa en Salud-Red de Trastornos Adictivos (RETICS-RTA), Palma de Mallorca, Spain.
| | - Jesús A García-Sevilla
- Laboratory of Neuropharmacology, IUNICS/IdISPa, University of the Balearic Islands, Spain; Redes Temáticas de Investigación Cooperativa en Salud-Red de Trastornos Adictivos (RETICS-RTA), Palma de Mallorca, Spain
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Luo F, Li SH, Tang H, Deng WK, Zhang Y, Liu Y. Phenylephrine enhances glutamate release in the medial prefrontal cortex through interaction with N-type Ca2+ channels and release machinery. J Neurochem 2014; 132:38-50. [PMID: 25196067 DOI: 10.1111/jnc.12941] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 08/27/2014] [Indexed: 11/30/2022]
Abstract
α1 -adrenoceptors (α1 -ARs) stimulation has been found to enhance excitatory processes in many brain regions. A recent study in our laboratory showed that α1 -ARs stimulation enhances glutamatergic transmission via both pre- and post-synaptic mechanisms in layer V/VI pyramidal cells of the rat medial prefrontal cortex (mPFC). However, a number of pre-synaptic mechanisms may contribute to α1 -ARs-induced enhancement of glutamate release. In this study, we blocked the possible post-synaptic action mediated by α1 -ARs to investigate how α1 -ARs activation regulates pre-synaptic glutamate release in layer V/VI pyramidal neurons of mPFC. We found that the α1 -ARs agonist phenylephrine (Phe) induced a significant enhancement of glutamatergic transmission. The Phe-induced potentiation was mediated by enhancing pre-synaptic glutamate release probability and increasing the number of release vesicles via a protein kinase C-dependent pathway. The mechanisms of Phe-induced potentiation included interaction with both glutamate release machinery and N-type Ca(2+) channels, probably via a pre-synaptic Gq /phospholipase C/protein kinase C pathway. Our results may provide a cellular and molecular mechanism that helps explain α1 -ARs-mediated influence on PFC cognitive functions. Alpha1 -adrenoceptor (α1 -ARs) stimulation has been reported to enhance glutamatergic transmission in layer V/VI pyramidal neurons of the rat medial prefrontal cortex (mPFC). We found that α1 -ARs agonist phenylephrine (Phe) increases pre-synaptic glutamate release probability and the number of released vesicles via interaction with both glutamate release machinery and N-type Ca(2+) channels. Our results may provide a cellular and molecular mechanism that helps explain α1 -ARs-mediated influence on PFC cognitive functions. Gq, Gq protein; PLC, phospholipase C; PKC, protein kinase C; AMPA, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid; NMDA, N-methyl-d-aspartate; Glu, glutamate; Phe, phenylephrine.
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Affiliation(s)
- Fei Luo
- Center for Neuropsychiatric Diseases, Institute of Life Science, Nanchang University, Nanchang, China
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Lippiello P, Hoxha E, Volpicelli F, Lo Duca G, Tempia F, Miniaci MC. Noradrenergic modulation of the parallel fiber-Purkinje cell synapse in mouse cerebellum. Neuropharmacology 2014; 89:33-42. [PMID: 25218865 DOI: 10.1016/j.neuropharm.2014.08.016] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 08/05/2014] [Accepted: 08/19/2014] [Indexed: 10/24/2022]
Abstract
The signals arriving to Purkinje cells via parallel fibers are essential for all tasks in which the cerebellum is involved, including motor control, learning new motor skills and calibration of reflexes. Since learning also requires the activation of adrenergic receptors, we investigated the effects of adrenergic receptor agonists on the main plastic site of the cerebellar cortex, the parallel fiber-Purkinje cell synapse. Here we show that noradrenaline serves as an endogenous ligand for both α1-and α2-adrenergic receptors to produce synaptic depression between parallel fibers and Purkinje cells. On the contrary, PF-EPSCs were potentiated by the β-adrenergic receptor agonist isoproterenol. This short-term potentiation was postsynaptically expressed, required protein kinase A, and was mimicked by the β2-adrenoceptor agonist clenbuterol, suggesting that the β2-adrenoceptors mediate the noradrenergic facilitation of synaptic transmission between parallel fibers and Purkinje cells. Moreover, β-adrenoceptor activation lowered the threshold for cerebellar long-term potentiation induced by 1 Hz parallel fiber stimulation. The presence of both α and β adrenergic receptors on Purkinje cells suggests the existence of bidirectional mechanisms of regulation allowing the noradrenergic afferents to refine the signals arriving to Purkinje cells at particular arousal states or during learning.
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Affiliation(s)
| | - Eriola Hoxha
- Dept. of Neuroscience, University of Torino, Torino, Italy; Neuroscience Institute Cavalieri Ottolenghi (NICO), Italy
| | - Floriana Volpicelli
- Dept. of Pharmacy, University of Naples Federico II, Naples, Italy; Institute of Genetics and Biophysics "Adriano Buzzati Traverso", CNR, Naples, Italy
| | | | - Filippo Tempia
- Dept. of Neuroscience, University of Torino, Torino, Italy; Neuroscience Institute Cavalieri Ottolenghi (NICO), Italy.
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Luo F, Guo NN, Li SH, Tang H, Liu Y, Zhang Y. Reduction of glutamate release probability and the number of releasable vesicles are required for suppression of glutamatergic transmission by β1-adrenoceptors in the medial prefrontal cortex. Neuropharmacology 2014; 83:89-98. [DOI: 10.1016/j.neuropharm.2014.03.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 03/23/2014] [Accepted: 03/29/2014] [Indexed: 11/28/2022]
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Luo F, Tang H, Li BM, Li SH. Activation of α1-adrenoceptors enhances excitatory synaptic transmission via a pre- and postsynaptic protein kinase C-dependent mechanism in the medial prefrontal cortex of rats. Eur J Neurosci 2014; 39:1281-93. [DOI: 10.1111/ejn.12495] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 12/16/2013] [Accepted: 12/25/2013] [Indexed: 11/30/2022]
Affiliation(s)
- Fei Luo
- Institute of Neurobiology & State Key Laboratory of Medical Neurobiology; Institutes of Brain Science; Fudan University; Shanghai 200032 China
| | - Hua Tang
- Center for Neuropsychiatric Diseases; Institute of Life Science; Nanchang University; Nanchang China
| | - Bao-ming Li
- Institute of Neurobiology & State Key Laboratory of Medical Neurobiology; Institutes of Brain Science; Fudan University; Shanghai 200032 China
- Center for Neuropsychiatric Diseases; Institute of Life Science; Nanchang University; Nanchang China
| | - Si-hai Li
- Center for Neuropsychiatric Diseases; Institute of Life Science; Nanchang University; Nanchang China
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