1
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Mena S, Cruikshank A, Best J, Nijhout HF, Reed MC, Hashemi P. Modulation of serotonin transporter expression by escitalopram under inflammation. Commun Biol 2024; 7:710. [PMID: 38851804 PMCID: PMC11162477 DOI: 10.1038/s42003-024-06240-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 04/24/2024] [Indexed: 06/10/2024] Open
Abstract
Selective serotonin reuptake inhibitors (SSRIs) are widely used for depression based on the monoamine deficiency hypothesis. However, the clinical use of these agents is controversial, in part because of their variable clinical efficacy and in part because of their delayed onset of action. Because of the complexities involved in replicating human disease and clinical dosing in animal models, the scientific community has not reached a consensus on the reasons for these phenomena. In this work, we create a theoretical hippocampal model incorporating escitalopram's pharmacokinetics, pharmacodynamics (competitive and non-competitive inhibition, and serotonin transporter (SERT) internalization), inflammation, and receptor dynamics. With this model, we simulate chronic oral escitalopram in mice showing that days to weeks are needed for serotonin levels to reach steady-state. We show escitalopram's chemical efficacy is diminished under inflammation. Our model thus offers mechanisms for how chronic escitalopram affects brain serotonin, emphasizing the importance of optimized dose and time for future antidepressant discoveries.
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Affiliation(s)
- Sergio Mena
- Department of Bioengineering, Imperial College London, London, SW7 2AZ, UK
| | | | - Janet Best
- Department of Mathematics, The Ohio State University, Columbus, OH, USA
| | - H F Nijhout
- Department of Biology, Duke University, Durham, NC, USA
| | - Michael C Reed
- Department of Mathematics, Duke University, Durham, NC, USA
| | - Parastoo Hashemi
- Department of Bioengineering, Imperial College London, London, SW7 2AZ, UK.
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2
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Dunham KE, Venton BJ. Electrochemical and biosensor techniques to monitor neurotransmitter changes with depression. Anal Bioanal Chem 2024; 416:2301-2318. [PMID: 38289354 PMCID: PMC10950978 DOI: 10.1007/s00216-024-05136-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 12/29/2023] [Accepted: 01/09/2024] [Indexed: 03/21/2024]
Abstract
Depression is a common mental illness. However, its current treatments, like selective serotonin reuptake inhibitors (SSRIs) and micro-dosing ketamine, are extremely variable between patients and not well understood. Three neurotransmitters: serotonin, histamine, and glutamate, have been proposed to be key mediators of depression. This review focuses on analytical methods to quantify these neurotransmitters to better understand neurological mechanisms of depression and how they are altered during treatment. To quantitatively measure serotonin and histamine, electrochemical techniques such as chronoamperometry and fast-scan cyclic voltammetry (FSCV) have been improved to study how specific molecular targets, like transporters and receptors, change with antidepressants and inflammation. Specifically, these studies show that different SSRIs have unique effects on serotonin reuptake and release. Histamine is normally elevated during stress, and a new inflammation hypothesis of depression links histamine and cytokine release. Electrochemical measurements revealed that stress increases histamine, decreases serotonin, and leads to changes in cytokines, like interleukin-6. Biosensors can also measure non-electroactive neurotransmitters, including glutamate and cytokines. In particular, new genetic sensors have shown how glutamate changes with chronic stress, as well as with ketamine treatment. These techniques have been used to characterize how ketamine changes glutamate and serotonin, and to understand how it is different from SSRIs. This review briefly outlines how these electrochemical techniques work, but primarily highlights how they have been used to understand the mechanisms of depression. Future studies should explore multiplexing techniques and personalized medicine using biomarkers in order to investigate multi-analyte changes to antidepressants.
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Affiliation(s)
- Kelly E Dunham
- Department of Chemistry, University of Virginia, Charlottesville, VA, 22904, USA
| | - B Jill Venton
- Department of Chemistry, University of Virginia, Charlottesville, VA, 22904, USA.
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3
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Witt CE, Mena S, Holmes J, Hersey M, Buchanan AM, Parke B, Saylor R, Honan LE, Berger SN, Lumbreras S, Nijhout FH, Reed MC, Best J, Fadel J, Schloss P, Lau T, Hashemi P. Serotonin is a common thread linking different classes of antidepressants. Cell Chem Biol 2023; 30:1557-1570.e6. [PMID: 37992715 DOI: 10.1016/j.chembiol.2023.10.009] [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: 03/07/2023] [Revised: 09/07/2023] [Accepted: 10/12/2023] [Indexed: 11/24/2023]
Abstract
Depression pathology remains elusive. The monoamine hypothesis has placed much focus on serotonin, but due to the variable clinical efficacy of monoamine reuptake inhibitors, the community is looking for alternative therapies such as ketamine (neurogenesis theory of antidepressant action). There is evidence that different classes of antidepressants may affect serotonin levels; a notion we test here. We measure hippocampal serotonin in mice with voltammetry and study the effects of acute challenges of escitalopram, fluoxetine, reboxetine, and ketamine. We find that pseudo-equivalent doses of these drugs similarly raise ambient serotonin levels, despite their differing pharmacodynamics because of differences in Uptake 1 and 2, rapid SERT trafficking, and modulation of serotonin by histamine. These antidepressants have different pharmacodynamics but have strikingly similar effects on extracellular serotonin. Our findings suggest that serotonin is a common thread that links clinically effective antidepressants, synergizing different theories of depression (synaptic plasticity, neurogenesis, and the monoamine hypothesis).
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Affiliation(s)
- Colby E Witt
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, USA
| | - Sergio Mena
- Department of Bioengineering, Imperial College London, London, UK
| | - Jordan Holmes
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, USA
| | - Melinda Hersey
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, USA; Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, USA
| | - Anna Marie Buchanan
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, USA; Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, USA
| | - Brenna Parke
- Department of Bioengineering, Imperial College London, London, UK
| | - Rachel Saylor
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, USA
| | - Lauren E Honan
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, USA
| | - Shane N Berger
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, USA
| | - Sara Lumbreras
- Department of Psychiatry and Psychotherapy, Biochemical Laboratory, Central Institute of Mental Health, Medical Faculty, Mannheim, Heidelberg University, Mannheim, Germany
| | | | - Michael C Reed
- Department of Mathematics, Duke University, Durham, NC, USA
| | - Janet Best
- Department of Mathematics, The Ohio State University, Columbus, OH, USA
| | - James Fadel
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, USA
| | - Patrick Schloss
- Department of Psychiatry and Psychotherapy, Biochemical Laboratory, Central Institute of Mental Health, Medical Faculty, Mannheim, Heidelberg University, Mannheim, Germany
| | - Thorsten Lau
- Department of Psychiatry and Psychotherapy, Biochemical Laboratory, Central Institute of Mental Health, Medical Faculty, Mannheim, Heidelberg University, Mannheim, Germany; Department of Neuroanatomy, Mannheim Centre for Translational Neuroscience, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Parastoo Hashemi
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, USA; Department of Bioengineering, Imperial College London, London, UK.
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4
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Agramunt J, Parke B, Mena S, Ubels V, Jimenez F, Williams G, Rhodes ADY, Limbu S, Hexter M, Knight L, Hashemi P, Kozlov AS, Higgins CA. Mechanical stimulation of human hair follicle outer root sheath cultures activates adjacent sensory neurons. SCIENCE ADVANCES 2023; 9:eadh3273. [PMID: 37889977 PMCID: PMC10610912 DOI: 10.1126/sciadv.adh3273] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 09/27/2023] [Indexed: 10/29/2023]
Abstract
Mechanical stimuli, such as stroking or pressing on the skin, activate mechanoreceptors transmitting information to the sensory nervous system and brain. It is well accepted that deflection of the hair fiber that occurs with a light breeze or touch directly activates the sensory neurons surrounding the hair follicle, facilitating transmission of mechanical information. Here, we hypothesized that hair follicle outer root sheath cells act as transducers of mechanical stimuli to sensory neurons surrounding the hair follicle. Using electrochemical analysis on human hair follicle preparations in vitro, we were able to show that outer root sheath cells release ATP and the neurotransmitters serotonin and histamine in response to mechanical stimulation. Using calcium imaging combined with pharmacology in a coculture of outer root sheath cells with sensory neurons, we found that the release of these three molecules from hair follicle cells leads to activation of sensory neurons.
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Affiliation(s)
- Julià Agramunt
- Department of Bioengineering, Imperial College London, London, UK
| | - Brenna Parke
- Department of Bioengineering, Imperial College London, London, UK
| | - Sergio Mena
- Department of Bioengineering, Imperial College London, London, UK
| | - Victor Ubels
- Department of Bioengineering, Imperial College London, London, UK
| | - Francisco Jimenez
- Mediteknia Clinic, Las Palmas, Gran Canaria, Spain
- University Fernando Pessoa Canarias, Gran Canaria, Spain
| | | | - Anna DY Rhodes
- Department of Bioengineering, Imperial College London, London, UK
| | - Summik Limbu
- Department of Bioengineering, Imperial College London, London, UK
| | - Melissa Hexter
- Department of Bioengineering, Imperial College London, London, UK
| | | | - Parastoo Hashemi
- Department of Bioengineering, Imperial College London, London, UK
| | - Andriy S. Kozlov
- Department of Bioengineering, Imperial College London, London, UK
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5
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Witt CE, Mena S, Holmes J, Hersey M, Buchanan AM, Parke B, Saylor R, Honan LE, Berger SN, Lumbreras S, Nijhout FH, Reed MC, Best J, Fadel J, Schloss P, Lau T, Hashemi P. Serotonin is a Common Thread Linking Different Classes of Antidepressants. RESEARCH SQUARE 2023:rs.3.rs-2741902. [PMID: 37034599 PMCID: PMC10081366 DOI: 10.21203/rs.3.rs-2741902/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
Depression pathology remains elusive. The monoamine hypothesis has placed much focus on serotonin, but due to the variable clinical efficacy of monoamine reuptake inhibitors, the community is looking for alternative therapies such as ketamine (synaptic plasticity and neurogenesis theory of antidepressant action). There is evidence that different classes of antidepressants may affect serotonin levels; a notion we test here. We measure hippocampal serotonin in mice with voltammetry and study the effects of acute challenges of antidepressants. We find that pseudo-equivalent doses of these drugs similarly raise ambient serotonin levels, despite their differing pharmacodynamics because of differences in Uptake 1 and 2, rapid SERT trafficking and modulation of serotonin by histamine. These antidepressants have different pharmacodynamics but have strikingly similar effects on extracellular serotonin. Our findings suggest that serotonin is a common thread that links clinically effective antidepressants, synergizing different theories of depression (synaptic plasticity, neurogenesis and the monoamine hypothesis).
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Affiliation(s)
- Colby E. Witt
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, USA
| | - Sergio Mena
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Jordan Holmes
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, USA
| | - Melinda Hersey
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, USA
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, USA
| | - Anna Marie Buchanan
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, USA
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, USA
| | - Brenna Parke
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Rachel Saylor
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, USA
| | - Lauren E. Honan
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, USA
| | - Shane N. Berger
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, USA
| | - Sara Lumbreras
- Department of Psychiatry and Psychotherapy, Biochemical Laboratory, Central Institute of Mental Health, Medical Faculty, Mannheim, Heidelberg University, Mannheim, Germany
| | | | | | - Janet Best
- Department of Mathematics, The Ohio State University, Columbus, OH, USA
| | - James Fadel
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, USA
| | - Patrick Schloss
- Department of Psychiatry and Psychotherapy, Biochemical Laboratory, Central Institute of Mental Health, Medical Faculty, Mannheim, Heidelberg University, Mannheim, Germany
| | - Thorsten Lau
- Department of Psychiatry and Psychotherapy, Biochemical Laboratory, Central Institute of Mental Health, Medical Faculty, Mannheim, Heidelberg University, Mannheim, Germany
- Department of Neuroanatomy, Mannheim Centre for Translational Neuroscience, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Parastoo Hashemi
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, USA
- Department of Bioengineering, Imperial College London, London, United Kingdom
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6
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An In Vivo Definition of Brain Histamine Dynamics Reveals Critical Neuromodulatory Roles for This Elusive Messenger. Int J Mol Sci 2022; 23:ijms232314862. [PMID: 36499189 PMCID: PMC9738190 DOI: 10.3390/ijms232314862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 10/31/2022] [Accepted: 11/01/2022] [Indexed: 12/05/2022] Open
Abstract
Histamine is well known for mediating peripheral inflammation; however, this amine is also found in high concentrations in the brain where its roles are much less known. In vivo chemical dynamics are difficult to measure, thus fundamental aspects of histamine's neurochemistry remain undefined. In this work, we undertake the first in-depth characterization of real time in vivo histamine dynamics using fast electrochemical tools. We find that histamine release is sensitive to pharmacological manipulation at the level of synthesis, packaging, autoreceptors and metabolism. We find two breakthrough aspects of histamine modulation. First, differences in H3 receptor regulation between sexes show that histamine release in female mice is much more tightly regulated than in male mice under H3 or inflammatory drug challenge. We hypothesize that this finding may contribute to hormone-mediated neuroprotection mechanisms in female mice. Second, a high dose of a commonly available antihistamine, the H1 receptor inverse agonist diphenhydramine, rapidly decreases serotonin levels. This finding highlights the sheer significance of pharmaceuticals on neuromodulation. Our study opens the path to better understanding and treating histamine related disorders of the brain (such as neuroinflammation), emphasizing that sex and modulation (of serotonin) are critical factors to consider when studying/designing new histamine targeting therapeutics.
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7
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Robbins EM, Castagnola E, Cui XT. Accurate and stable chronic in vivo voltammetry enabled by a replaceable subcutaneous reference electrode. iScience 2022; 25:104845. [PMID: 35996579 PMCID: PMC9391596 DOI: 10.1016/j.isci.2022.104845] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 06/16/2022] [Accepted: 07/22/2022] [Indexed: 01/12/2023] Open
Abstract
In vivo sensing of neurotransmitters has provided valuable insight into both healthy and diseased brain. However, chronically implanted Ag/AgCl reference electrodes suffer from degradationgradation, resulting in errors in the potential at the working electrode. Here, we report a simple, effective way to protect in vivo sensing measurements from reference polarization with a replaceable subcutaneously implanted reference. We compared a brain-implanted reference and a subcutaneous reference and observed no difference in impedance or dopamine redox peak separation in an acute preparation. Chronically, peak background potential and dopamine oxidation potential shifts were eliminated for three weeks. Scanning electron microscopy shows changes in surface morphology and composition of chronically implanted Ag/AgCl electrodes, and postmortem histology reveals extensive cell death and gliosis in the surrounding tissue. As accurate reference potentials are critical to in vivo electrochemistry applications, this simple technique can improve a wide and diverse assortment of in vivo preparations.
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Affiliation(s)
- Elaine Marie Robbins
- Department of Bioengineering, University of Pittsburgh, 5057 Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA 15260, USA
| | - Elisa Castagnola
- Department of Bioengineering, University of Pittsburgh, 5057 Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA 15260, USA
| | - Xinyan Tracy Cui
- Department of Bioengineering, University of Pittsburgh, 5057 Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA 15260, USA
- Center for Neural Basis of Cognition, Pittsburgh, PA, USA
- McGowan Institute for Regenerative Medicine, Pittsburgh, PA, USA
- Corresponding author
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8
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Hersey M, Reneaux M, Berger SN, Mena S, Buchanan AM, Ou Y, Tavakoli N, Reagan LP, Clopath C, Hashemi P. A tale of two transmitters: serotonin and histamine as in vivo biomarkers of chronic stress in mice. J Neuroinflammation 2022; 19:167. [PMID: 35761344 PMCID: PMC9235270 DOI: 10.1186/s12974-022-02508-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 06/01/2022] [Indexed: 12/12/2022] Open
Abstract
Background Stress-induced mental illnesses (mediated by neuroinflammation) pose one of the world’s most urgent public health challenges. A reliable in vivo chemical biomarker of stress would significantly improve the clinical communities’ diagnostic and therapeutic approaches to illnesses, such as depression. Methods Male and female C57BL/6J mice underwent a chronic stress paradigm. We paired innovative in vivo serotonin and histamine voltammetric measurement technologies, behavioral testing, and cutting-edge mathematical methods to correlate chemistry to stress and behavior. Results Inflammation-induced increases in hypothalamic histamine were co-measured with decreased in vivo extracellular hippocampal serotonin in mice that underwent a chronic stress paradigm, regardless of behavioral phenotype. In animals with depression phenotypes, correlations were found between serotonin and the extent of behavioral indices of depression. We created a high accuracy algorithm that could predict whether animals had been exposed to stress or not based solely on the serotonin measurement. We next developed a model of serotonin and histamine modulation, which predicted that stress-induced neuroinflammation increases histaminergic activity, serving to inhibit serotonin. Finally, we created a mathematical index of stress, Si and predicted that during chronic stress, where Si is high, simultaneously increasing serotonin and decreasing histamine is the most effective chemical strategy to restoring serotonin to pre-stress levels. When we pursued this idea pharmacologically, our experiments were nearly identical to the model’s predictions. Conclusions This work shines the light on two biomarkers of chronic stress, histamine and serotonin, and implies that both may be important in our future investigations of the pathology and treatment of inflammation-induced depression. Supplementary Information The online version contains supplementary material available at 10.1186/s12974-022-02508-9.
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Affiliation(s)
- Melinda Hersey
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA.,Department of Pharmacology, Physiology, & Neuroscience, University of South Carolina School of Medicine, Columbia, SC, 29209, USA
| | - Melissa Reneaux
- Department of Bioengineering, Imperial College London, London, SW7 2AZ, UK
| | - Shane N Berger
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | - Sergio Mena
- Department of Bioengineering, Imperial College London, London, SW7 2AZ, UK
| | - Anna Marie Buchanan
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | - Yangguang Ou
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | - Navid Tavakoli
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | - Lawrence P Reagan
- Department of Pharmacology, Physiology, & Neuroscience, University of South Carolina School of Medicine, Columbia, SC, 29209, USA.,Columbia VA Health Care Systems, Columbia, SC, 29208, USA
| | - Claudia Clopath
- Department of Bioengineering, Imperial College London, London, SW7 2AZ, UK
| | - Parastoo Hashemi
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA. .,Department of Bioengineering, Imperial College London, London, SW7 2AZ, UK.
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9
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Mena S, Dietsch S, Berger SN, Witt CE, Hashemi P. Novel, User-Friendly Experimental and Analysis Strategies for Fast Voltammetry: 1. The Analysis Kid for FSCV. ACS MEASUREMENT SCIENCE AU 2021; 1:11-19. [PMID: 36785731 PMCID: PMC9836074 DOI: 10.1021/acsmeasuresciau.1c00003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Fast-scan cyclic voltammetry (FSCV) at carbon fiber microelectrodes measures low concentrations of analytes in biological systems. There are ongoing efforts to simplify FSCV analysis, and several custom platforms are available for filtering and multimodal analysis of FSCV signals, but there is no single, easily accessible platform that has the capacity for all of these features. Here we present The Analysis Kid: currently, the only free, open-source cloud application that does not require a specialized runtime environment and is easily accessible via common browsers. We show that a user-friendly interface can analyze multiplatform file formats to provide multimodal visualization of FSCV color plots with digital background subtraction. We highlight key features that allow interactive calibration and semiautomatic parametric analysis via peak finding algorithms to automatically detect the maximum amplitude, area under the curve, and clearance rate of the signal. Finally, The Analysis Kid enables semiautomatic fitting of data with Michaelis-Menten kinetics with single or dual reuptake models. The Analysis Kid can be freely accessed at http://analysis-kid.hashemilab.com/. The web application code is found, under an MIT license, at https://github.com/sermeor/The-Analysis-Kid.
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Affiliation(s)
- Sergio Mena
- Department of Bioengineering, Imperial College London, London SW7 2AZ, United Kingdom
| | - Solene Dietsch
- Department of Bioengineering, Imperial College London, London SW7 2AZ, United Kingdom
| | - Shane N. Berger
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Colby E. Witt
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Parastoo Hashemi
- Department of Bioengineering, Imperial College London, London SW7 2AZ, United Kingdom
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
- . Phone: +44
20 7594 9193
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10
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Extended sawhorse waveform for stable zinc detection with fast-scan cyclic voltammetry. Anal Bioanal Chem 2021; 413:6727-6735. [PMID: 34268588 DOI: 10.1007/s00216-021-03529-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 07/01/2021] [Accepted: 07/06/2021] [Indexed: 10/20/2022]
Abstract
Zinc (Zn(II)) is a divalent cation involved in regulating intracellular signal transduction and gene expression through transcription factor activity, and can act as a metal neurotransmitter by modulating synaptic activity and neuronal plasticity. Previous research has demonstrated spatial heterogeneity of Zn(II) in the brain, has estimated extracellular concentrations of Zn(II) across various brain regions, and has measured rapid intracellular changes in Zn(II) concentration during glutamate flux. Despite this work, quantification of rapid extracellular Zn(II) release from neurons, on a millisecond time scale, in real time has remained difficult with existing technologies. Here, we have developed an electrochemical waveform, called the "extended sawhorse waveform (ESW)," for fast-scan cyclic voltammetry detection at carbon-fiber microelectrodes which enabled rapid and stable Zn(II) monitoring over time. This waveform was developed to overcome existing challenges in monitoring metallotransmitters stably over time electrochemically by introducing a brief cleaning step to facilitate rapid cleaning of the electrode surface in between scans. The ESW scans from 0.5 V down to -1.0 V, up to 1.45 V for 3 ms (cleaning step), and back to 0.5 V at a scan rate of 400 V/s. Repeated introductions of Zn(II) at the electrode using a traditional waveform cause plating which ultimately deteriorates the sensitivity over time; however, using the ESW, significant improvements in stability were observed. Overall, we provide a unique approach to monitor and quantitate rapid Zn(II) signaling in the brain at carbon electrodes which will impact our ability to advance fundamental knowledge of Zn(II) involvement in extracellular signaling pathways in the brain.
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11
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Inflammation-Induced Histamine Impairs the Capacity of Escitalopram to Increase Hippocampal Extracellular Serotonin. J Neurosci 2021; 41:6564-6577. [PMID: 34083254 DOI: 10.1523/jneurosci.2618-20.2021] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 02/03/2021] [Accepted: 02/04/2021] [Indexed: 01/11/2023] Open
Abstract
Commonly prescribed selective serotonin reuptake inhibitors (SSRIs) inhibit the serotonin transporter to correct a presumed deficit in extracellular serotonin signaling during depression. These agents bring clinical relief to many who take them; however, a significant and growing number of individuals are resistant to SSRIs. There is emerging evidence that inflammation plays a significant role in the clinical variability of SSRIs, though how SSRIs and inflammation intersect with synaptic serotonin modulation remains unknown. In this work, we use fast in vivo serotonin measurement tools to investigate the nexus between serotonin, inflammation, and SSRIs. Upon acute systemic lipopolysaccharide (LPS) administration in male and female mice, we find robust decreases in extracellular serotonin in the mouse hippocampus. We show that these decreased serotonin levels are supported by increased histamine activity (because of inflammation), acting on inhibitory histamine H3 heteroreceptors on serotonin terminals. Importantly, under LPS-induced histamine increase, the ability of escitalopram to augment extracellular serotonin is impaired because of an off-target action of escitalopram to inhibit histamine reuptake. Finally, we show that a functional decrease in histamine synthesis boosts the ability of escitalopram to increase extracellular serotonin levels following LPS. This work reveals a profound effect of inflammation on brain chemistry, specifically the rapidity of inflammation-induced decreased extracellular serotonin, and points the spotlight at a potentially critical player in the pathology of depression, histamine. The serotonin/histamine homeostasis thus, may be a crucial new avenue in improving serotonin-based treatments for depression.SIGNIFICANCE STATEMENT Acute LPS-induced inflammation (1) increases CNS histamine, (2) decreases CNS serotonin (via inhibitory histamine receptors), and (3) prevents a selective serotonin reuptake inhibitor (SSRI) from effectively increasing extracellular serotonin. A targeted depletion of histamine recovers SSRI-induced increases in extracellular hippocampal serotonin.
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12
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Naganuma F, Yoshikawa T. Organic Cation Transporters in Brain Histamine Clearance: Physiological and Psychiatric Implications. Handb Exp Pharmacol 2021; 266:169-185. [PMID: 33641029 DOI: 10.1007/164_2021_447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Histamine acts as a neurotransmitter in the central nervous system and is involved in numerous physiological functions. Recent studies have identified the causative role of decreased histaminergic systems in various neurological disorders. Thus, the brain histamine system has attracted attention as a therapeutic target to improve brain function. Neurotransmitter clearance is one of the most important processes for the regulation of neuronal activity and is an essential target for diverse drugs. Our previous study has shown the importance of histamine N-methyltransferase for the inactivation of brain histamine and the intracellular localization of this enzyme; the study indicated that the transport system for the movement of positively charged histamine from the extracellular to intracellular space is a prerequisite for histamine inactivation. Several studies on in vitro astrocytic histamine transport have indicated the contribution of organic cation transporter 3 (OCT3) and plasma membrane monoamine transporter (PMAT) in histamine uptake, although the importance of these transporters in in vivo histamine clearance remains unknown. Immunohistochemical analyses have revealed the expression of OCT3 and PMAT on neurons, emphasizing the importance of investigating neuronal histamine uptake. Further studies using knockout mice or fast-scan cyclic voltammetry will accelerate the research on histamine transporters. In this review article, we summarize histamine transport assays and describe the candidate transporters responsible for histamine transport in the brain.
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Affiliation(s)
- Fumito Naganuma
- Department of Pharmacology, Tohoku University Graduate School of Medicine, Sendai, Japan.,Division of Pharmacology, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Takeo Yoshikawa
- Department of Pharmacology, Tohoku University Graduate School of Medicine, Sendai, Japan.
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Best J, Duncan W, Sadre-Marandi F, Hashemi P, Nijhout HF, Reed M. Autoreceptor control of serotonin dynamics. BMC Neurosci 2020; 21:40. [PMID: 32967609 PMCID: PMC7509944 DOI: 10.1186/s12868-020-00587-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 08/29/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Serotonin is a neurotransmitter that has been linked to a wide variety of behaviors including feeding and body-weight regulation, social hierarchies, aggression and suicidality, obsessive compulsive disorder, alcoholism, anxiety, and affective disorders. Full understanding involves genomics, neurochemistry, electrophysiology, and behavior. The scientific issues are daunting but important for human health because of the use of selective serotonin reuptake inhibitors and other pharmacological agents to treat disorders. This paper presents a new deterministic model of serotonin metabolism and a new systems population model that takes into account the large variation in enzyme and transporter expression levels, tryptophan input, and autoreceptor function. RESULTS We discuss the steady state of the model and the steady state distribution of extracellular serotonin under different hypotheses on the autoreceptors and we show the effect of tryptophan input on the steady state and the effect of meals. We use the deterministic model to interpret experimental data on the responses in the hippocampus of male and female mice, and to illustrate the short-time dynamics of the autoreceptors. We show there are likely two reuptake mechanisms for serotonin and that the autoreceptors have long-lasting influence and compare our results to measurements of serotonin dynamics in the substantia nigra pars reticulata. We also show how histamine affects serotonin dynamics. We examine experimental data that show very variable response curves in populations of mice and ask how much variation in parameters in the model is necessary to produce the observed variation in the data. Finally, we show how the systems population model can potentially be used to investigate specific biological and clinical questions. CONCLUSIONS We have shown that our new models can be used to investigate the effects of tryptophan input and meals and the behavior of experimental response curves in different brain nuclei. The systems population model incorporates individual variation and can be used to investigate clinical questions and the variation in drug efficacy. The codes for both the deterministic model and the systems population model are available from the authors and can be used by other researchers to investigate the serotonergic system.
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Affiliation(s)
- Janet Best
- Department of Mathematics, The Ohio State University, 231 W 18th Ave., Columbus, OH 43210 USA
| | - William Duncan
- Department of Mathematics, Duke University, Durham, NC 27708 USA
| | | | - Parastoo Hashemi
- Department of Bioengineering, Imperial College, London, SW7 2AZ UK
| | | | - Michael Reed
- Department of Mathematics, Duke University, Durham, NC 27708 USA
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Nehru L, Chinnathambi S, Fazio E, Neri F, Leonardi SG, Bonavita A, Neri G. Electrochemical Sensing of Serotonin by a Modified MnO 2-Graphene Electrode. BIOSENSORS 2020; 10:bios10040033. [PMID: 32252484 PMCID: PMC7235847 DOI: 10.3390/bios10040033] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 03/23/2020] [Accepted: 03/30/2020] [Indexed: 05/15/2023]
Abstract
The development of MnO2-graphene (MnO2-GR) composite by microwave irradiation method and its application as an electrode material for the selective determination of serotonin (SE), popularly known as "happy chemical", is reported. Anchoring MnO2 nanoparticles on graphene, yielded MnO2-GR composite with a large surface area, improved electron transport, high conductivity and numerous channels for rapid diffusion of electrolyte ions. The composite was characterized by X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and scanning electron microscopy (SEM) for assessing the actual composition, structure and morphology. The MnO2-GR composite modified glassy carbon electrode (GCE) exhibited an excellent electrochemical activity towards the detection of SE in phosphate buffer saline (PBS) at physiological pH of 7.0. Under optimum conditions, the modified electrode could be applied to the quantification of serotonin by square wave voltammetry over a wide linear range of 0.1 to 800 µM with the lowest detection limit of 10 nM (S/N = 3). The newly fabricated sensor also exhibited attractive features such as good anti-interference ability, high reproducibility and long-term stability.
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Affiliation(s)
- Lavanya Nehru
- Department of Bioelectronics and Biosensors, Alagappa University, Karaikudi 630003, India
- Department of Engineering, University of Messina, 98166 Messina, Italy; (S.G.L.); (A.B.); (G.N.)
- Correspondence: (L.N.); (S.C.); Tel.: +91-9442563637 (S.C.)
| | - Sekar Chinnathambi
- Department of Bioelectronics and Biosensors, Alagappa University, Karaikudi 630003, India
- Correspondence: (L.N.); (S.C.); Tel.: +91-9442563637 (S.C.)
| | - Enza Fazio
- Department of Mathematical and Computational Sciences, Physics and Earth Physics, University of Messina, 98166 Messina, Italy; (E.F.); (F.N.)
| | - Fortunato Neri
- Department of Mathematical and Computational Sciences, Physics and Earth Physics, University of Messina, 98166 Messina, Italy; (E.F.); (F.N.)
| | | | - Anna Bonavita
- Department of Engineering, University of Messina, 98166 Messina, Italy; (S.G.L.); (A.B.); (G.N.)
| | - Giovanni Neri
- Department of Engineering, University of Messina, 98166 Messina, Italy; (S.G.L.); (A.B.); (G.N.)
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Shin M, Wang Y, Borgus JR, Venton BJ. Electrochemistry at the Synapse. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2019; 12:297-321. [PMID: 30707593 PMCID: PMC6989097 DOI: 10.1146/annurev-anchem-061318-115434] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Electrochemical measurements of neurotransmitters provide insight into the dynamics of neurotransmission. In this review, we describe the development of electrochemical measurements of neurotransmitters and how they started with extrasynaptic measurements but now are pushing toward synaptic measurements. Traditionally, biosensors or fast-scan cyclic voltammetry have monitored extrasynaptic levels of neurotransmitters, such as dopamine, serotonin, adenosine, glutamate, and acetylcholine. Amperometry and electrochemical cytometry techniques have revealed mechanisms of exocytosis, suggesting partial release. Advances in nanoelectrodes now allow spatially resolved, electrochemical measurements in a synapse, which is only 20-100 nm wide. Synaptic measurements of dopamine and acetylcholine have been made. In this article, electrochemical measurements are also compared to optical imaging and mass spectrometry measurements, and while these other techniques provide enhanced spatial or chemical information, electrochemistry is best at monitoring real-time neurotransmission. Future challenges include combining electrochemistry with these other techniques in order to facilitate multisite and multianalyte monitoring.
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Affiliation(s)
| | | | - Jason R Borgus
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22901, USA;
| | - B Jill Venton
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22901, USA;
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Ou Y, Buchanan AM, Witt CE, Hashemi P. Frontiers in Electrochemical Sensors for Neurotransmitter Detection: Towards Measuring Neurotransmitters as Chemical Diagnostics for Brain Disorders. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2019; 11:2738-2755. [PMID: 32724337 PMCID: PMC7386554 DOI: 10.1039/c9ay00055k] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
It is extremely challenging to chemically diagnose disorders of the brain. There is hence great interest in designing and optimizing tools for direct detection of chemical biomarkers implicated in neurological disorders to improve diagnosis and treatment. Tools that are capable of monitoring brain chemicals, neurotransmitters in particular, need to be biocompatible, perform with high spatiotemporal resolution, and ensure high selectivity and sensitivity. Recent advances in electrochemical methods are addressing these criteria; the resulting devices demonstrate great promise for in vivo neurotransmitter detection. None of these devices are currently used for diagnostic purposes, however these cutting-edge technologies are promising more sensitive, selective, faster, and less invasive measurements. Via this review we highlight significant technical advances and in vivo studies, performed in the last 5 years, that we believe will facilitate the development of diagnostic tools for brain disorders.
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Affiliation(s)
- Yangguang Ou
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia SC
| | - Anna Marie Buchanan
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia SC
| | - Colby E. Witt
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia SC
| | - Parastoo Hashemi
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia SC
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17
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Denton AR, Samaranayake SA, Kirchner KN, Roscoe RF, Berger SN, Harrod SB, Mactutus CF, Hashemi P, Booze RM. Selective monoaminergic and histaminergic circuit dysregulation following long-term HIV-1 protein exposure. J Neurovirol 2019; 25:540-550. [PMID: 31102184 DOI: 10.1007/s13365-019-00754-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 04/06/2019] [Accepted: 04/15/2019] [Indexed: 12/21/2022]
Abstract
Between 30 and 60% of HIV-seropositive individuals develop symptoms of clinical depression and/or apathy. Dopamine and serotonin are associated with motivational alterations; however, histamine is less well studied. In the present study, we used fast-scan cyclic voltammetry in HIV-1 transgenic (Tg) rats to simultaneously analyze the kinetics of nucleus accumbens dopamine (DA), prefrontal cortical serotonin (5-HT), and hypothalamic histamine (HA). For voltammetry, subjects were 15 HIV-1 Tg (7 male, 8 female) and 20 F344/N (11 male, 9 female) adult rats. Both serotonergic and dopaminergic release and reuptake kinetics were decreased in HIV-1 Tg animals relative to controls. In contrast, rates of histamine release and reuptake increased in HIV-1 Tg rats. Additionally, we used immunohistochemical (IHC) methods to identify histaminergic neurons in the tuberomammillary nucleus (TMN) of the hypothalamus. For IHC, subjects were 9 HIV-1 Tg (5 male, 4 female) and 9 F344/N (5 male, 4 female) adult rats. Although the total number of TMN histaminergic cells did not differ between HIV-1 Tg rats and F344/N controls, a significant sex effect was found, with females having an increased number of histaminergic neurons, relative to males. Collectively, these findings illustrate neurochemical alterations that potentially underlie or exacerbate the pathogenesis of clinical depression and/or apathy in HIV-1.
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Affiliation(s)
- Adam R Denton
- Behavioral Neuroscience Laboratory, Department of Psychology, University of South Carolina, Columbia, SC, USA
| | | | - Kristin N Kirchner
- Behavioral Neuroscience Laboratory, Department of Psychology, University of South Carolina, Columbia, SC, USA
| | - Robert F Roscoe
- Behavioral Neuroscience Laboratory, Department of Psychology, University of South Carolina, Columbia, SC, USA
| | - Shane N Berger
- Department of Chemistry, University of South Carolina, Columbia, SC, USA
| | - Steven B Harrod
- Behavioral Neuroscience Laboratory, Department of Psychology, University of South Carolina, Columbia, SC, USA
| | - Charles F Mactutus
- Behavioral Neuroscience Laboratory, Department of Psychology, University of South Carolina, Columbia, SC, USA
| | - Parastoo Hashemi
- Department of Chemistry, University of South Carolina, Columbia, SC, USA
| | - Rosemarie M Booze
- Behavioral Neuroscience Laboratory, Department of Psychology, University of South Carolina, Columbia, SC, USA.
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Best J, Nijhout HF, Samaranayake S, Hashemi P, Reed M. A mathematical model for histamine synthesis, release, and control in varicosities. Theor Biol Med Model 2017; 14:24. [PMID: 29228949 PMCID: PMC5725884 DOI: 10.1186/s12976-017-0070-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Accepted: 10/27/2017] [Indexed: 12/24/2022] Open
Abstract
Background Histamine (HA), a small molecule that is synthesized from the amino acid histidine, plays an important role in the immune system where it is associated with allergies, inflammation, and T-cell regulation. In the brain, histamine is stored in mast cells and other non-neuronal cells and also acts as a neurotransmitter. The histamine neuron cell bodies are in the tuberomammillary (TM) nucleus of the hypothalamus and these neurons send projections throughout the central nervous system (CNS), in particular to the cerebral cortex, amygdala, basal ganglia, hippocampus, thalamus, retina, and spinal cord. HA neurons make few synapses, but release HA from the cell bodies and from varicosities when the neurons fire. Thus the HA neural system seems to modulate and control the HA concentration in projection regions. It is known that high HA levels in the extracellular space inhibit serotonin release, so HA may play a role in the etiology of depression. Results We compare model predictions to classical physiological experiments on HA half-life, the concentration of brain HA after histidine loading, and brain HA after histidine is dramatically increased or decreased in the diet. The model predictions are also consistent with in vivo experiments in which extracellular HA is measured, using Fast Scan Cyclic Voltammetry, in the premammillary nucleus (PM) after a 2 s antidromic stimulation of the TM, both without and in the presence of the H3 autoreceptor antagonist thioperamide. We show that the model predicts well the temporal behavior of HA in the extracellular space over 30 s in both experiments. Conclusions Our ability to measure in vivo histamine dynamics in the extracellular space after stimulation presents a real opportunity to understand brain function and control. The observed extracellular dynamics depends on synthesis, storage, neuronal firing, release, reuptake, glial cells, and control by autoreceptors, as well as the behavioral state of the animal (for example, depression) or the presence of neuroinflammation. In this complicated situation, the mathematical model will be useful for interpreting data and conducting in silico experiments to understand causal mechanisms. And, better understanding can suggest new therapeutic drug targets.
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Affiliation(s)
- Janet Best
- Department of Mathematics, Ohio State University, 231 W 18th Ave, MW 614, Columbus, 43210, OH, USA.
| | - H F Nijhout
- Department of Biology, Duke University, Durham, 27708, NC, USA
| | - Srimal Samaranayake
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, 29208, SC, USA
| | - Parastoo Hashemi
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, 29208, SC, USA
| | - Michael Reed
- Department of Mathematics, Duke University, Durham, 27708, NC, USA
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Abdalla A, Atcherley CW, Pathirathna P, Samaranayake S, Qiang B, Peña E, Morgan SL, Heien ML, Hashemi P. In Vivo Ambient Serotonin Measurements at Carbon-Fiber Microelectrodes. Anal Chem 2017; 89:9703-9711. [PMID: 28795565 DOI: 10.1021/acs.analchem.7b01257] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The mechanisms that control extracellular serotonin levels in vivo are not well-defined. This shortcoming makes it very challenging to diagnose and treat the many psychiatric disorders in which serotonin is implicated. Fast-scan cyclic voltammetry (FSCV) can measure rapid serotonin release and reuptake events but cannot report critically important ambient serotonin levels. In this Article, we use fast-scan controlled adsorption voltammetry (FSCAV), to measure serotonin's steady-state, extracellular chemistry. We characterize the "Jackson" voltammetric waveform for FSCAV and show highly stable, selective, and sensitive ambient serotonin measurements in vitro. In vivo, we report basal serotonin levels in the CA2 region of the hippocampus as 64.9 ± 2.3 nM (n = 15 mice, weighted average ± standard error). We electrochemically and pharmacologically verify the selectivity of the serotonin signal. Finally, we develop a statistical model that incorporates the uncertainty in in vivo measurements, in addition to electrode variability, to more critically analyze the time course of pharmacological data. Our novel method is a uniquely powerful analysis tool that can provide deeper insights into the mechanisms that control serotonin's extracellular levels.
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Affiliation(s)
- Aya Abdalla
- Department of Chemistry and Biochemistry, University of South Carolina , 631 Sumter Street, Columbia, South Carolina 29208, United States
| | | | - Pavithra Pathirathna
- Department of Chemistry and Biochemistry, University of South Carolina , 631 Sumter Street, Columbia, South Carolina 29208, United States
| | - Srimal Samaranayake
- Department of Chemistry and Biochemistry, University of South Carolina , 631 Sumter Street, Columbia, South Carolina 29208, United States
| | - Beidi Qiang
- Department of Statistics, University of South Carolina , 1523 Greene Street, Columbia, South Carolina 29208, United States
| | - Edsel Peña
- Department of Statistics, University of South Carolina , 1523 Greene Street, Columbia, South Carolina 29208, United States
| | - Stephen L Morgan
- Department of Chemistry and Biochemistry, University of South Carolina , 631 Sumter Street, Columbia, South Carolina 29208, United States
| | - Michael L Heien
- Department of Chemistry and Biochemistry, University of Arizona , 1306 East University Blvd., Tucson, Arizona 85721, United States
| | - Parastoo Hashemi
- Department of Chemistry and Biochemistry, University of South Carolina , 631 Sumter Street, Columbia, South Carolina 29208, United States
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Genetic Analysis of Histamine Signaling in Larval Zebrafish Sleep. eNeuro 2017; 4:eN-NWR-0286-16. [PMID: 28275716 PMCID: PMC5334454 DOI: 10.1523/eneuro.0286-16.2017] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 02/07/2017] [Accepted: 02/09/2017] [Indexed: 01/11/2023] Open
Abstract
Pharmacological studies in mammals and zebrafish suggest that histamine plays an important role in promoting arousal. However, genetic studies using rodents with disrupted histamine synthesis or signaling have revealed only subtle or no sleep/wake phenotypes. Studies of histamine function in mammalian arousal are complicated by its production in cells of the immune system and its roles in humoral and cellular immunity, which can have profound effects on sleep/wake states. To avoid this potential confound, we used genetics to explore the role of histamine in regulating sleep in zebrafish, a diurnal vertebrate in which histamine production is restricted to neurons in the brain. Similar to rodent genetic studies, we found that zebrafish that lack histamine due to mutation of histidine decarboxylase (hdc) exhibit largely normal sleep/wake behaviors. Zebrafish containing predicted null mutations in several histamine receptors also lack robust sleep/wake phenotypes, although we are unable to verify that these mutants are completely nonfunctional. Consistent with some rodent studies, we found that arousal induced by overexpression of the neuropeptide hypocretin (Hcrt) or by stimulation of hcrt-expressing neurons is not blocked in hdc or hrh1 mutants. We also found that the number of hcrt-expressing or histaminergic neurons is unaffected in animals that lack histamine or Hcrt signaling, respectively. Thus, while acute pharmacological manipulation of histamine signaling has been shown to have profound effects on zebrafish and mammalian sleep, our results suggest that chronic loss of histamine signaling due to genetic mutations has only subtle effects on sleep in zebrafish, similar to rodents.
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