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Stamos J, Stalnaker K, Teegala S, Routh VH, Beck KD. Effects of glucose modulation in lateral hypothalamus on motivated behavior to obtain sucrose in an operant task. Appetite 2023; 189:106621. [PMID: 37311483 DOI: 10.1016/j.appet.2023.106621] [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: 04/11/2023] [Revised: 06/02/2023] [Accepted: 06/03/2023] [Indexed: 06/15/2023]
Abstract
Orexin neurons in the Lateral Hypothalamus (LH) play an important role in food seeking behavior. Approximately 60 percent of LH orexin neurons are inhibited by elevated extracellular glucose. It has been shown that elevated LH glucose decreases conditioned place preference for a food associated chamber. However, it has never been shown how modulation of LH extracellular glucose effects a rat's motivation to work for food. In this experiment we used reverse microdialysis to modulate extracellular glucose levels in LH during an operant task. Results from a progressive ratio task demonstrated that 4 mM glucose perfusion significantly decreased the animal's motivation to work for sucrose pellets while not effecting the hedonic value of the pellets. In a second experiment we demonstrated that 4 mM but not 2.5 mM glucose perfusion was sufficient to significantly decrease the number of sucrose pellets earned. Finally, we showed that modulating LH extracellular glucose mid-session from 0.7 mM to 4 mM did not affect behavior. This indicates that once feeding behavior has begun the animal becomes unresponsive to changes in extracellular glucose levels in LH. Taken together these experiments indicate that LH glucose sensing neurons play an important role in motivation to initiate feeding. However, once consumption has begun it is likely that feeding is controlled by brain regions downstream of LH.
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Affiliation(s)
- Joshua Stamos
- Neurobehavioral Research Laboratory, Research Service, Veterans Affairs New Jersey Health Care System, East Orange, NJ, USA
| | - Katherine Stalnaker
- School of Graduate Studies, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Suraj Teegala
- School of Graduate Studies, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Vanessa H Routh
- School of Graduate Studies, Rutgers, The State University of New Jersey, Newark, NJ, USA; Department of Pharmacology, Physiology & Neuroscience, Rutgers - New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Kevin D Beck
- Neurobehavioral Research Laboratory, Research Service, Veterans Affairs New Jersey Health Care System, East Orange, NJ, USA; School of Graduate Studies, Rutgers, The State University of New Jersey, Newark, NJ, USA; Department of Pharmacology, Physiology & Neuroscience, Rutgers - New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA.
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Maness EB, Blumenthal SA, Burk JA. Dual orexin/hypocretin receptor antagonism attenuates NMDA receptor hypofunction-induced attentional impairments in a rat model of schizophrenia. Behav Brain Res 2023; 450:114497. [PMID: 37196827 PMCID: PMC10330488 DOI: 10.1016/j.bbr.2023.114497] [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: 02/14/2023] [Revised: 05/12/2023] [Accepted: 05/14/2023] [Indexed: 05/19/2023]
Abstract
Schizophrenia is a neuropsychiatric condition that is associated with impaired attentional processing and performance. Failure to support increasing attentional load may result, in part, from inhibitory failure in attention-relevant cortical regions, and available antipsychotics often fail to address this issue. Orexin/hypocretin receptors are found throughout the brain and are expressed on neurons relevant to both attention and schizophrenia, highlighting them as a potential target to treat schizophrenia-associated attentional dysfunction. In the present experiment, rats (N = 14) trained in a visual sustained attention task that required discrimination of trials which presented a visual signal from trials during which no signal was presented. Once trained, rats were then co-administered the psychotomimetic N-methyl-D-aspartate (NMDA) receptor antagonist dizocilpine (MK-801: 0 or 0.1mg/kg, intraperitoneal injections) and the dual orexin receptor antagonist filorexant (MK-6096: 0, 0.1, or 1mM, intracerebroventricular infusions) prior to task performance across six sessions. Dizocilpine impaired overall accuracy during signal trials, slowed reaction times for correctly-responded trials, and increased the number of omitted trials throughout the task. Dizocilpine-induced increases in signal trial deficits, correct response latencies, and errors of omission were reduced following infusions of the 0.1mM, but not 1mM, dose of filorexant. As such, orexin receptor blockade may improve attentional deficits in a state of NMDA receptor hypofunction.
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Affiliation(s)
- Eden B Maness
- Department of Psychological Sciences, College of William and Mary, Williamsburg, VA, 23187, USA; VA Boston Healthcare System and Department of Psychiatry, Harvard Medical School, West Roxbury, MA, 02132, USA.
| | - Sarah A Blumenthal
- Center for Translational Social Neuroscience, Emory National Primate Research Center, Emory University, Atlanta, GA, 30329, USA
| | - Joshua A Burk
- Department of Psychological Sciences, College of William and Mary, Williamsburg, VA, 23187, USA
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Ten-Blanco M, Flores Á, Cristino L, Pereda-Pérez I, Berrendero F. Targeting the orexin/hypocretin system for the treatment of neuropsychiatric and neurodegenerative diseases: from animal to clinical studies. Front Neuroendocrinol 2023; 69:101066. [PMID: 37015302 DOI: 10.1016/j.yfrne.2023.101066] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 03/15/2023] [Accepted: 03/30/2023] [Indexed: 04/06/2023]
Abstract
Orexins (also known as hypocretins) are neuropeptides located exclusively in hypothalamic neurons that have extensive projections throughout the central nervous system and bind two different G protein-coupled receptors (OX1R and OX2R). Since its discovery in 1998, the orexin system has gained the interest of the scientific community as a potential therapeutic target for the treatment of different pathological conditions. Considering previous basic science research, a dual orexin receptor antagonist, suvorexant, was the first orexin agent to be approved by the US Food and Drug Administration to treat insomnia. In this review, we discuss and update the main preclinical and human studies involving the orexin system with several psychiatric and neurodegenerative diseases. This system constitutes a nice example of how basic scientific research driven by curiosity can be the best route to the generation of new and powerful pharmacological treatments.
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Affiliation(s)
- Marc Ten-Blanco
- Faculty of Experimental Sciences, Universidad Francisco de Vitoria, 28223 Pozuelo de Alarcón, Madrid, Spain
| | - África Flores
- Pharmacology Unit, Department of Pathology and Experimental Therapeutics, Neurosciences Institute, University of Barcelona and Bellvitge University Hospital-IDIBELL, 08908 L'Hospitalet de Llobregat, Barcelona, Spain
| | - Luigia Cristino
- Endocannabinoid Research Group, Institute of Biomolecular Chemistry (ICB), National Research Council (CNR), Pozzuoli, Italy
| | - Inmaculada Pereda-Pérez
- Faculty of Experimental Sciences, Universidad Francisco de Vitoria, 28223 Pozuelo de Alarcón, Madrid, Spain
| | - Fernando Berrendero
- Faculty of Experimental Sciences, Universidad Francisco de Vitoria, 28223 Pozuelo de Alarcón, Madrid, Spain.
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Maness EB, Blumenthal SA, Burk JA. Dual orexin/hypocretin receptor antagonism attenuates attentional impairments in an NMDA receptor hypofunction model of schizophrenia. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.05.527043. [PMID: 36778441 PMCID: PMC9915718 DOI: 10.1101/2023.02.05.527043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Schizophrenia is a neuropsychiatric condition that is associated with impaired attentional processing and performance. Failure to support increasing attentional load may result, in part, from abnormally overactive basal forebrain projections to the prefrontal cortex, and available antipsychotics often fail to address this issue. Orexin/hypocretin receptors are expressed on corticopetal cholinergic neurons, and their blockade has been shown to decrease the activity of cortical basal forebrain outputs and prefrontal cortical cholinergic neurotransmission. In the present experiment, rats (N = 14) trained in a visual sustained attention task that required discrimination of trials which presented a visual signal from trials during which no signal was presented. Once trained, rats were then co-administered the psychotomimetic N-methyl-D-aspartate (NMDA) receptor antagonist dizocilpine (MK-801: 0 or 0.1 mg/kg, intraperitoneal injections) and the dual orexin receptor antagonist filorexant (MK-6096: 0, 0.1, or 1 mM, intracerebroventricular infusions) prior to task performance across six sessions. Dizocilpine impaired overall accuracy during signal trials, slowed reaction times for correctly-responded trials, and increased the number of omitted trials throughout the task. Dizocilpine-induced increases in signal trial deficits, correct response latencies, and errors of omission were reduced following infusions of the 0.1 mM, but not 1 mM, dose of filorexant. Orexin receptor blockade, perhaps through anticholinergic mechanisms, may improve attentional deficits in a state of NMDA receptor hypofunction. Highlights Schizophrenia is associated with attentional deficits that may stem from abnormally reactive BF projections to the prefrontal cortexOrexin receptor antagonists decrease acetylcholine release and reduce prefrontal cortical activityThe dual orexin receptor antagonist filorexant alleviated impairments of attention following NMDA receptor blockade.
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Affiliation(s)
- Eden B. Maness
- VA Boston Healthcare System and Department of Psychiatry, Harvard Medical School, West Roxbury, MA, 02132, USA,Department of Psychological Sciences, College of William and Mary, Williamsburg, VA, 23187, USA,Please address correspondence to: Eden B. Maness, West Roxbury VA Medical Center, 1400 Veterans of Foreign Wars Parkway, West Roxbury, MA, 02132, Tel: 857-203-4359,
| | - Sarah A. Blumenthal
- Center for Translational Social Neuroscience, Emory National Primate Research Center, Emory University, Atlanta, GA, 30329, USA
| | - Joshua A. Burk
- Department of Psychological Sciences, College of William and Mary, Williamsburg, VA, 23187, USA
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Malik JA, Yaseen Z, Thotapalli L, Ahmed S, Shaikh MF, Anwar S. Understanding translational research in schizophrenia: A novel insight into animal models. Mol Biol Rep 2023; 50:3767-3785. [PMID: 36692676 PMCID: PMC10042983 DOI: 10.1007/s11033-023-08241-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 01/04/2023] [Indexed: 01/25/2023]
Abstract
Schizophrenia affects millions of people worldwide and is a major challenge for the scientific community. Like most psychotic diseases, it is also considered a complicated mental disorder caused by an imbalance in neurotransmitters. Due to the complexity of neuropathology, it is always a complicated disorder. The lack of proper understanding of the pathophysiology makes the disorder unmanageable in clinical settings. However, due to recent advances in animal models, we hope we can have better therapeutic approaches with more success in clinical settings. Dopamine, glutamate, GABA, and serotonin are the neurotransmitters involved in the pathophysiology of schizophrenia. Various animal models have been put forward based on these neurotransmitters, including pharmacological, neurodevelopmental, and genetic models. Polymorphism of genes such as dysbindin, DICS1, and NRG1 has also been reported in schizophrenia. Hypothesis based on dopamine, glutamate, and serotonin are considered successful models of schizophrenia on which drug therapies have been designed to date. New targets like the orexin system, muscarinic and nicotinic receptors, and cannabinoid receptors have been approached to alleviate the negative and cognitive symptoms. The non-pharmacological models like the post-weaning social isolation model (maternal deprivation), the isolation rearing model etc. have been also developed to mimic the symptoms of schizophrenia and to create and test new approaches of drug therapy which is a breakthrough at present in psychiatric disorders. Different behavioral tests have been evaluated in these specific models. This review will highlight the currently available animal models and behavioral tests in psychic disorders concerning schizophrenia.
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Affiliation(s)
- Jonaid Ahmad Malik
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research, Guwahati, India.,Department of Biomedical Engineering, Indian Institute of Technology Ropar, Rupnagar, India
| | - Zahid Yaseen
- Department of Pharmaceutical Biotechnology, Delhi Pharmaceutical Sciences and Research University, Delhi, India
| | - Lahari Thotapalli
- Department of Pharmaceutical Sciences, JNTU University, Anantapur, India
| | - Sakeel Ahmed
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research, Ahmedabad, Gujarat, 382355, India
| | - Mohd Farooq Shaikh
- Neuropharmacology Research Strength, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, 47500, Bandar Sunway, Selangor, Malaysia. .,School of Dentistry and Medical Sciences, Charles Sturt University, Orange, 2800, New South Wales, Australia.
| | - Sirajudheen Anwar
- Department of Pharmacology, College of Pharmacy, University of Hail, Hail, 81422, Saudi Arabia.
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Elam HB, Donegan JJ, Hsieh J, Lodge DJ. Gestational buprenorphine exposure disrupts dopamine neuron activity and related behaviors in adulthood. eNeuro 2022; 9:ENEURO.0499-21.2022. [PMID: 35851301 PMCID: PMC9337603 DOI: 10.1523/eneuro.0499-21.2022] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 05/13/2022] [Accepted: 05/20/2022] [Indexed: 11/21/2022] Open
Abstract
Opioid misuse among pregnant women is rapidly increasing in the United States. The number of maternal opioid-related diagnoses increased by 131% in the last ten years, resulting in an increased number of infants exposed to opioids in utero and a subsequent increase in infants developing neonatal abstinence syndrome (NAS). The most prescribed treatment to combat maternal opioid use disorder is buprenorphine, a partial μ-opioid receptor agonist and κ-opioid receptor antagonist. Buprenorphine treatment effectively reduces NAS but has been associated with disrupted cortical development and neurodevelopmental consequences in childhood. Less is known about the long-term neurodevelopmental consequences following buprenorphine exposure in utero Previous research has shown that gestational buprenorphine exposure can induce anxiety- and depressive-like phenotypes in adult rats, suggesting that exposure to buprenorphine in utero may render individuals more susceptible to psychiatric illness in adulthood. A common pathology observed across multiple psychiatric illnesses is dopamine system dysfunction. Here, we administered the highly-abused opioid, oxycodone (10 mg/kg, i.p.) or a therapeutic used to treat opioid use disorder, buprenorphine (1 mg/kg, i.p) to pregnant Sprague Dawley rats from gestational day 11 through 21, then examined neurophysiological alterations in the mesolimbic dopamine system and dopamine-dependent behaviors in adult offspring. We found that gestational exposure to buprenorphine or oxycodone increases dopamine neuron activity in adulthood. Moreover, prenatal buprenorphine exposure disrupts the afferent regulation of dopamine neuron activity in the ventral tegmental area (VTA). Taken together, we posit that gestational buprenorphine or oxycodone exposure can have profound effects on the mesolimbic dopamine system in adulthood.Significance StatementThe opioid epidemic in the United States is a growing problem that affects people from all demographics, including pregnant women. In 2017, nearly 21,000 pregnant women reported misusing opioids during pregnancy, which can lead to many physiological and neurodevelopmental complications in infants. To combat illicit opioid use during pregnancy, buprenorphine is the priority treatment option, as it reduces illicit opioid use and alleviates symptoms of neonatal abstinence syndrome in infants. However, less is known about the long-term neurophysiological consequences of in utero opioid or buprenorphine exposure. Here, we demonstrate that both oxycodone and buprenorphine exposure, in utero, can result in aberrant dopamine system function in adult rats. These results provide evidence of potential long-lasting effects of opioid exposure during development.
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Affiliation(s)
- Hannah B Elam
- Department of Pharmacology and Center for Biomedical Neuroscience, University of Texas Health Science Center, San Antonio, TX, 78229, USA
| | - Jennifer J Donegan
- Department of Pharmacology and Center for Biomedical Neuroscience, University of Texas Health Science Center, San Antonio, TX, 78229, USA
- Department of Psychiatry and Behavioral Sciences, Dell Medical School at UT Austin, Austin, TX, USA
| | - Jenny Hsieh
- Department of Neuroscience, Developmental and Regenerative Biology, University of Texas at San Antonio, San Antonio, TX, 78249, USA
- Brain Health Consortium, University of Texas at San Antonio, San Antonio, TX, 78249, USA
| | - Daniel J Lodge
- Department of Pharmacology and Center for Biomedical Neuroscience, University of Texas Health Science Center, San Antonio, TX, 78229, USA
- South Texas Veterans Health Care System, Audie L. Murphy Division, San Antonio, USA
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Demidova A, Kahl E, Fendt M. Orexin deficiency affects sensorimotor gating and its amphetamine-induced impairment. Prog Neuropsychopharmacol Biol Psychiatry 2022; 116:110517. [PMID: 35101602 DOI: 10.1016/j.pnpbp.2022.110517] [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: 12/16/2021] [Revised: 01/19/2022] [Accepted: 01/20/2022] [Indexed: 11/17/2022]
Abstract
The orexin neuropeptides have an important role in the regulation of the sleep/wake cycle and foraging, as well as in reward processing and emotions. Furthermore, recent research implicates the orexin system in different behavioral endophenotypes of neuropsychiatric diseases such as social avoidance and cognitive flexibility. Utilizing orexin-deficient mice, the present study tested the hypothesis that orexin is involved in two further mouse behavioral endophenotypes of neuropsychiatric disorders, i.e., sensorimotor gating and amphetamine sensitivity. The data revealed that orexin-deficient mice expressed a deficit in sensorimotor gating, measured by prepulse inhibition of the startle response. Amphetamine treatment impaired prepulse inhibition in wildtype and heterozygous orexin-deficient mice, but had no effects in homozygous orexin-deficient mice. Furthermore, locomotor activity and center time in the open field was not affected by orexin deficiency but was similarly increased or decreased, respectively, by amphetamine treatment in all genotypes. These data indicate that the orexin system modulates prepulse inhibition and is involved in mediating amphetamine's effect on prepulse inhibition. Future studies should investigate whether pharmacological manipulations of the orexin system can be used to treat neuropsychiatric diseases associated with deficits in sensorimotor gating, such as schizophrenia or attention deficit hyperactivity disorder.
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Affiliation(s)
- Alexandrina Demidova
- Institute for Pharmacology and Toxicology, Otto-von-Guericke University Magdeburg, Germany; Psychology Master Program, Otto-von-Guericke University Magdeburg, Germany
| | - Evelyn Kahl
- Institute for Pharmacology and Toxicology, Otto-von-Guericke University Magdeburg, Germany
| | - Markus Fendt
- Institute for Pharmacology and Toxicology, Otto-von-Guericke University Magdeburg, Germany; Psychology Master Program, Otto-von-Guericke University Magdeburg, Germany; Center for Behavioral Brain Sciences, Otto-von-Guericke University Magdeburg, Germany.
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Neurobiology of the Orexin System and Its Potential Role in the Regulation of Hedonic Tone. Brain Sci 2022; 12:brainsci12020150. [PMID: 35203914 PMCID: PMC8870430 DOI: 10.3390/brainsci12020150] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 12/14/2021] [Accepted: 12/14/2021] [Indexed: 01/13/2023] Open
Abstract
Orexin peptides comprise two neuropeptides, orexin A and orexin B, that bind two G-protein coupled receptors (GPCRs), orexin receptor 1 (OXR1) and orexin receptor 2 (OXR2). Although cell bodies that produce orexin peptides are localized in a small area comprising the lateral hypothalamus and adjacent regions, orexin-containing fibres project throughout the neuraxis. Although orexins were initially described as peptides that regulate feeding behaviour, research has shown that orexins are involved in diverse functions that range from the modulation of autonomic functions to higher cognitive functions, including reward-seeking, behaviour, attention, cognition, and mood. Furthermore, disruption in orexin signalling has been shown in mood disorders that are associated with low hedonic tone or anhedonia, including depression, anxiety, attention deficit hyperactivity disorder, and addiction. Notably, projections of orexin neurons overlap circuits involved in the modulation of hedonic tone. Evidence shows that orexins may potentiate hedonic behaviours by increasing the feeling of pleasure or reward to various signalling, whereas dysregulation of orexin signalling may underlie low hedonic tone or anhedonia. Further, orexin appears to play a key role in regulating behaviours in motivationally charged situations, such as food-seeking during hunger, or drug-seeking during withdrawal. Therefore, it would be expected that dysregulation of orexin expression or signalling is associated with changes in hedonic tone. Further studies investigating this association are warranted.
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Perez SM, McCoy AM, Prevot TD, Mian MY, Carreno FR, Frazer A, Cook JM, Sibille E, Lodge DJ. Hippocampal α5-GABA A Receptors Modulate Dopamine Neuron Activity in the Rat Ventral Tegmental Area. BIOLOGICAL PSYCHIATRY GLOBAL OPEN SCIENCE 2022; 3:78-86. [PMID: 36712569 PMCID: PMC9874136 DOI: 10.1016/j.bpsgos.2021.12.010] [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: 11/08/2021] [Revised: 11/22/2021] [Accepted: 12/16/2021] [Indexed: 02/01/2023] Open
Abstract
Background Aberrant dopamine neuron activity is attributable to hyperactivity in hippocampal subfields driving a pathological increase in dopamine neuron activity, which is positively correlated with psychosis in humans. Evidence indicates that hippocampal hyperactivity is due to loss of intrinsic GABAergic (gamma-aminobutyric acidergic) inhibition. We have previously demonstrated that hippocampal GABAergic neurotransmission can be modulated by targeting α5-GABAA receptors, which are preferentially expressed in hippocampal regions. Positive and negative allosteric modulators of α5-GABAA receptors (α5-PAMs and α5-NAMs) elicit effects on hippocampal-dependent behaviors. We posited that the selective manipulation of hippocampal inhibition, using α5-PAMs or α5-NAMs, would modulate dopamine activity in control rats. Further, α5-PAMs would reverse aberrant dopamine neuron activity in a rodent model with schizophrenia-related pathophysiologies (methylazoxymethanol acetate [MAM] model). Methods We performed in vivo extracellular recordings of ventral tegmental area dopamine neurons in anesthetized rats to compare the effects of two novel, selective α5-PAMs (GL-II-73, MP-III-022), a nonselective α-PAM (midazolam), and two selective α5-NAMs (L-655,708, TB 21007) in control and MAM-treated male Sprague Dawley rats (n = 5-9). Results Systemic or intracranial administration of selective α5-GABAA receptor modulators regulated dopamine activity. Specifically, both α5-NAMs increased dopamine neuron activity in control rats, whereas GL-II-73, MP-III-022, and L-655,708 attenuated aberrant dopamine neuron activity in MAM-treated rats, an effect mediated by the ventral hippocampus. Conclusions This study demonstrated that α5-GABAA receptor modulation can regulate dopamine neuron activity under control or abnormal activity, providing additional evidence that α5-PAMs and α5-NAMs may have therapeutic applications in psychosis and other psychiatric diseases where aberrant hippocampal activity is present.
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Affiliation(s)
- Stephanie M. Perez
- Department of Pharmacology and Center for Biomedical Neuroscience, UT Health San Antonio, San Antonio, Texas,Audie L. Murphy Memorial Veterans Hospital, South Texas Veterans Health Care System, San Antonio, Texas,Address correspondence to Stephanie M. Perez, Ph.D.
| | - Alexandra M. McCoy
- Department of Pharmacology and Center for Biomedical Neuroscience, UT Health San Antonio, San Antonio, Texas,Audie L. Murphy Memorial Veterans Hospital, South Texas Veterans Health Care System, San Antonio, Texas
| | - Thomas D. Prevot
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - Md Yeunus Mian
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin
| | - Flavia R. Carreno
- Department of Pharmacology and Center for Biomedical Neuroscience, UT Health San Antonio, San Antonio, Texas
| | - Alan Frazer
- Department of Pharmacology and Center for Biomedical Neuroscience, UT Health San Antonio, San Antonio, Texas,Audie L. Murphy Memorial Veterans Hospital, South Texas Veterans Health Care System, San Antonio, Texas
| | - James M. Cook
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin
| | - Etienne Sibille
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada,Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada
| | - Daniel J. Lodge
- Department of Pharmacology and Center for Biomedical Neuroscience, UT Health San Antonio, San Antonio, Texas,Audie L. Murphy Memorial Veterans Hospital, South Texas Veterans Health Care System, San Antonio, Texas
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Subramanian S, Ravichandran M. Orexin receptors: Targets and applications. Fundam Clin Pharmacol 2021; 36:72-80. [PMID: 34464995 DOI: 10.1111/fcp.12723] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 08/18/2021] [Accepted: 08/26/2021] [Indexed: 01/02/2023]
Abstract
Over the years, elucidating targets from the neural circuits that can be used to treat disorders pertaining to the nervous system and extending their scope to other systems have always proved interesting to researchers. The role of various peptides and neurotransmitters has been elucidated and is being developed as therapeutic targets. Out of these, orexins are neuropeptides produced in the hypothalamus that stimulate a specific type of G-Protein coupled receptors (GPCR) called orexin receptors and bring about various physiological and pathological roles. Orexin receptors are of interest not only because of their wide applications such as insomnia, obesity, and inflammatory disorders but also because of their contribution to promising aspects of drug discovery such as optogenetics and their tremendous growth from the stage of being orphans to orexins. This review will discuss in detail the structure of orexin receptors, their physiological role, and various applications in disease states adding a note on agonists and antagonists and finally summarizing the recent drug approvals in the field.
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Affiliation(s)
- Subhiksha Subramanian
- Department of Pharmacology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India
| | - Mirunalini Ravichandran
- Department of Pharmacology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India
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