1
|
Romanova OL, Blagonravov ML, Dzhuvalyakov PG, Torshin VI, Barinov EK, Ershov AV, Kislov MA. [Assessment of histological changes in the lungs and Bax and Bcl-2 expression in bronchial epithelium, alveolar type 1 cells and neutrophils of rats in poisoning with baclofen]. Sud Med Ekspert 2024; 67:36-41. [PMID: 39440563 DOI: 10.17116/sudmed20246705136] [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] [Indexed: 10/25/2024]
Abstract
OBJECTIVE To study the histological changes in lung of rats, evaluate their dynamics and determine the Bax and Bcl-2 genes expression in bronchial epithelium, alveolar type 1 cells and neutrophils at different times after the administration of baclofen. MATERIAL AND METHODS The experiment was conducted on 20 mature (at the age of 20 weeks) male Wistar rats with a mass of 290-350 g, distributed in 4 groups (5 rats in each). Animals in the control group did not receive baclofen. Rats in experimental groups received baclofen at a dose of 85 mg/kg: in the 1st group, the experiment duration was 3 hours (time to maximum observed blood drug concentration); in the 2nd group - 4.5 h (drug half-life and time to maximum observed concentration of the main drug's metabolite - beta-[p-chlorophenyl])-gamma-hydroxybutyric acid in the blood); in the 3rd group - 24 h. RESULTS A complex of pathological reactions developed in lungs of experimental animals when baclofen muscle relaxant was administered, namely circulatory disturbances at all levels of the microvasculature (venular and capillary congestion, hemorrhages in the interalveolar septums, alveoli, sludge), emphysema, sites of which punctuated with atelectases and dystelectases. The complex of pathological changes in the lungs had a certain dynamics and reached its highest severity by the 24th hour. Bax expression was strong, while Bcl-2 expression was moderate in the immunohistochemical (IHC) study of bronchical epithelium and alveolar type 1 cells, Bax and Bcl-2 expression in neutrophils was moderate in rats of the 1st group. The expression of Bax and Bcl-2 was strong in the bronchial epithelium and alveolar type 1 cells, the expression of Bax in neutrophils was moderate, and BCL-2 - strong in animals of the 2nd group. The expression of Bax in bronchial epithelium and alveolar type 1 cells was moderate, expression of Bcl-2 in bronchial epithelium and alveolar type 1 cells - strong, expression of Bax in neutrophils - weak and expression of Bcl-2 - strong among the rats of the 3rd group. CONCLUSION The complex of pathological changes in lungs had a certain dynamic. Data on the histological changes in lungs in combination with the results of the chemical study, can be used to diagnose the poisoning by baclofen and to establish the time since the drug was administered. The results obtained during the IHC study suggest the involvement of apoptosis in the development of lesion of bronchial epithelium and alveolar type 1 cells. In addition, the expression of Bcl-2 in epithelial cells may play a role in the process of their regeneration.
Collapse
Affiliation(s)
- O L Romanova
- Peoples' Friendship University of Russia named after Patrice Lumumba, Moscow, Russia
- Avtsyn Research Institute of Human Morphology of the Petrovsky National Research Centre of Surgery, Moscow, Russia
| | - M L Blagonravov
- Peoples' Friendship University of Russia named after Patrice Lumumba, Moscow, Russia
| | - P G Dzhuvalyakov
- Peoples' Friendship University of Russia named after Patrice Lumumba, Moscow, Russia
- Avtsyn Research Institute of Human Morphology of the Petrovsky National Research Centre of Surgery, Moscow, Russia
| | - V I Torshin
- Peoples' Friendship University of Russia named after Patrice Lumumba, Moscow, Russia
| | - E Kh Barinov
- Peoples' Friendship University of Russia named after Patrice Lumumba, Moscow, Russia
- Russian University of Medicine, Moscow, Russia
| | - A V Ershov
- V.A. Negovsky Research Institute of General Reanimatology of the Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology, Moscow, Russia
- I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - M A Kislov
- Pirogov Russian National Research Medical University, Moscow, Russia
| |
Collapse
|
2
|
Kilduff TS. The mystery of gamma-hydoxybutyrate efficacy in narcolepsy type 1. Sleep 2023; 46:zsad156. [PMID: 37260387 PMCID: PMC10485562 DOI: 10.1093/sleep/zsad156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Indexed: 06/02/2023] Open
Affiliation(s)
- Thomas S Kilduff
- Center for Neuroscience, Biosciences Division, SRI International, Menlo Park, CA, USA
| |
Collapse
|
3
|
Kim M, Oh S, Kim S, Ji M, Choi B, Bae JW, Lee YS, Paik MJ, Lee S. Alcohol perturbed locomotor behavior, metabolism, and pharmacokinetics of gamma-hydroxybutyric acid in rats. Biomed Pharmacother 2023; 164:114992. [PMID: 37301134 DOI: 10.1016/j.biopha.2023.114992] [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: 03/25/2023] [Revised: 05/30/2023] [Accepted: 06/06/2023] [Indexed: 06/12/2023] Open
Abstract
Gamma-hydroxybutyric acid (GHB), both a metabolic precursor and product of gamma-aminobutyric acid (GABA), is a central nervous system depressant used for the treatment of narcolepsy-associated cataplexy and alcohol withdrawal. However, administration of GHB with alcohol (ethanol) is a major cause of hospitalizations related to GHB intoxication. In this study, we investigated locomotor behavior as well as metabolic and pharmacokinetic interactions following co-administration of GHB and ethanol in rats. The locomotor behavior of rats was evaluated following the intraperitoneal administration of GHB (sodium salt, 500 mg/kg) and/or ethanol (2 g/kg). Further, time-course urinary metabolic profiling of GHB and its biomarker metabolites glutamic acid, GABA, succinic acid, 2,4-dihydroxybutyric acid (OH-BA), 3,4-OH-BA, and glycolic acid as well as pharmacokinetic analysis were performed. GHB/ethanol co-administration significantly reduced locomotor activity, compared to the individual administration of GHB or ethanol. The urinary and plasma concentrations of GHB and other target compounds, except for 2,4-OH-BA, were significantly higher in the GHB/ethanol co-administration group than the group administered only GHB. The pharmacokinetic analysis results showed that the co-administration of GHB and ethanol significantly increased the half-life of GHB while the total clearance decreased. Moreover, a comparison of the metabolite-to-parent drug area under the curve ratios demonstrated that the metabolic pathways of GHB, such α- and β-oxidation, were inhibited by ethanol. Consequently, the co-administration of GHB and ethanol aggravated the metabolism and elimination of GHB and enhanced its sedative effect. These findings will contribute to clinical interpretation of GHB intoxication.
Collapse
Affiliation(s)
- Mingyu Kim
- College of Pharmacy, Keimyung University, 1095 Dalgubeol-daero, Dalseo-gu, Daegu 42601, the Republic of Korea
| | - Songjin Oh
- College of Pharmacy, Sunchon National University, 25 Jungang-ro, Suncheon 57922, the Republic of Korea
| | - Suji Kim
- College of Pharmacy, Keimyung University, 1095 Dalgubeol-daero, Dalseo-gu, Daegu 42601, the Republic of Korea
| | - Moongi Ji
- College of Pharmacy, Sunchon National University, 25 Jungang-ro, Suncheon 57922, the Republic of Korea
| | - Byeongchan Choi
- College of Pharmacy, Sunchon National University, 25 Jungang-ro, Suncheon 57922, the Republic of Korea
| | - Jung-Woo Bae
- College of Pharmacy, Keimyung University, 1095 Dalgubeol-daero, Dalseo-gu, Daegu 42601, the Republic of Korea
| | - Yong Sup Lee
- College of Pharmacy, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, the Republic of Korea
| | - Man-Jeong Paik
- College of Pharmacy, Sunchon National University, 25 Jungang-ro, Suncheon 57922, the Republic of Korea.
| | - Sooyeun Lee
- College of Pharmacy, Keimyung University, 1095 Dalgubeol-daero, Dalseo-gu, Daegu 42601, the Republic of Korea.
| |
Collapse
|
4
|
Børresen ML, Lundstrøm KE, Ifversen M, Jennum PJ. Sodium oxybate (Xyrem) treatment in severely sleep-deprived child with Epstein-Barr virus encephalitis with lesion of sleep-wake regulation system: a case report. Sleep Med 2019; 62:29-31. [PMID: 31526967 DOI: 10.1016/j.sleep.2019.03.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Revised: 03/06/2019] [Accepted: 03/07/2019] [Indexed: 10/27/2022]
Abstract
We present the effect of exogenous sodium oxybate (GHB) in a severely tormented boy unable to sleep and unable to be anesthetized due to a lesion in the sleep initiation system involving the tracks between the ventrolateral preoptic nucleus and the reticular system. We bypassed the system by using sodium oxybate's effect on the cortical GHB and GABAB receptors involved in the initiation and maintenance of sleep.
Collapse
Affiliation(s)
- Malene Landbo Børresen
- Department of Pediatric and Adolescent Medicine, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.
| | - Kaare Engell Lundstrøm
- Department of Pediatric and Adolescent Medicine, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Marianne Ifversen
- Department of Pediatric and Adolescent Medicine, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Poul Jørgen Jennum
- Danish Center of Sleep Medicine, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| |
Collapse
|
5
|
Szabo ST, Thorpy MJ, Mayer G, Peever JH, Kilduff TS. Neurobiological and immunogenetic aspects of narcolepsy: Implications for pharmacotherapy. Sleep Med Rev 2018; 43:23-36. [PMID: 30503715 DOI: 10.1016/j.smrv.2018.09.006] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 09/22/2018] [Accepted: 09/27/2018] [Indexed: 01/19/2023]
Abstract
Excessive daytime sleepiness (EDS) and cataplexy are common symptoms of narcolepsy, a sleep disorder associated with the loss of hypocretin/orexin (Hcrt) neurons. Although only a few drugs have received regulatory approval for narcolepsy to date, treatment involves diverse medications that affect multiple biochemical targets and neural circuits. Clinical trials have demonstrated efficacy for the following classes of drugs as narcolepsy treatments: alerting medications (amphetamine, methylphenidate, modafinil/armodafinil, solriamfetol [JZP-110]), antidepressants (tricyclic antidepressants, selective serotonin reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors), sodium oxybate, and the H3-receptor inverse agonist/antagonist pitolisant. Enhanced catecholamine availability and regulation of locus coeruleus (LC) norepinephrine (NE) neuron activity is likely central to the therapeutic activity of most of these compounds. LC NE neurons are integral to sleep/wake regulation and muscle tone; reduced excitatory input to the LC due to compromise of Hcrt/orexin neurons (likely due to autoimmune factors) results in LC NE dysregulation and contributes to narcolepsy/cataplexy symptoms. Agents that increase catecholamines and/or LC activity may mitigate EDS and cataplexy by elevating NE regulation of GABAergic inputs from the amygdala. Consequently, novel medications and treatment strategies aimed at preserving and/or modulating Hcrt/orexin-LC circuit integrity are warranted in narcolepsy/cataplexy.
Collapse
Affiliation(s)
- Steven T Szabo
- Duke University Medical Center, Durham, NC, USA; Durham Veterans Affairs Medical Center, Durham, NC, USA.
| | | | | | - John H Peever
- University of Toronto, Toronto, Ontario M5S 3G5, Canada.
| | - Thomas S Kilduff
- Center for Neuroscience, Biosciences Division, SRI International, Menlo Park, CA 94025, USA.
| |
Collapse
|
6
|
de Beaurepaire R. A Review of the Potential Mechanisms of Action of Baclofen in Alcohol Use Disorder. Front Psychiatry 2018; 9:506. [PMID: 30459646 PMCID: PMC6232933 DOI: 10.3389/fpsyt.2018.00506] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 09/25/2018] [Indexed: 12/17/2022] Open
Abstract
Baclofen, a GABA-B receptor agonist, is a promising treatment for alcohol use disorder (AUD). Its mechanism of action in this condition is unknown. GABA-B receptors interact with many biological systems potentially involved in AUD, including transduction pathways and neurotransmitter systems. Preclinical studies have shown that GABA-B receptors are involved in memory storage and retrieval, reward, motivation, mood and anxiety; neuroimaging studies in humans show that baclofen produces region-specific alterations in cerebral activity; GABA-B receptor activation may have neuroprotective effects; baclofen also has anti-inflammatory properties that may be of interest in the context of addiction. However, none of these biological effects fully explain the mechanism of action of baclofen in AUD. Data from clinical studies have provided a certain number of elements which may be useful for the comprehension of its mechanism of action: baclofen typically induces a state of indifference toward alcohol; the effective dose of baclofen in AUD is extremely variable from one patient to another; higher treatment doses correlate with the severity of the addiction; many of the side effects of baclofen resemble those of alcohol, raising the possibility that baclofen acts as a substitution drug; usually, however, there is no tolerance to the effects of baclofen during long-term AUD treatment. In the present article, the biological effects of baclofen are reviewed in the light of its clinical effects in AUD, assuming that, in many instances, clinical effects can be reliable indicators of underlying biological processes. In conclusion, it is proposed that baclofen may suppress the Pavlovian association between cues and rewards through an action in a critical part of the dopaminergic network (the amygdala), thereby normalizing the functional connectivity in the reward network. It is also proposed that this action of baclofen is made possible by the fact that baclofen and alcohol act on similar brain systems in certain regions of the brain.
Collapse
|
7
|
Fore S, Palumbo F, Pelgrims R, Yaksi E. Information processing in the vertebrate habenula. Semin Cell Dev Biol 2017; 78:130-139. [PMID: 28797836 DOI: 10.1016/j.semcdb.2017.08.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 07/12/2017] [Accepted: 08/05/2017] [Indexed: 10/19/2022]
Abstract
The habenula is a brain region that has gained increasing popularity over the recent years due to its role in processing value-related and experience-dependent information with a strong link to depression, addiction, sleep and social interactions. This small diencephalic nucleus is proposed to act as a multimodal hub or a switchboard, where inputs from different brain regions converge. These diverse inputs to the habenula carry information about the sensory world and the animal's internal state, such as reward expectation or mood. However, it is not clear how these diverse habenular inputs interact with each other and how such interactions contribute to the function of habenular circuits in regulating behavioral responses in various tasks and contexts. In this review, we aim to discuss how information processing in habenular circuits, can contribute to specific behavioral programs that are attributed to the habenula.
Collapse
Affiliation(s)
- Stephanie Fore
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian University of Science and Technology, Olav Kyrres Gate 9, Norwegian Brain Centre, 7491 Trondheim, Norway
| | - Fabrizio Palumbo
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian University of Science and Technology, Olav Kyrres Gate 9, Norwegian Brain Centre, 7491 Trondheim, Norway
| | - Robbrecht Pelgrims
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian University of Science and Technology, Olav Kyrres Gate 9, Norwegian Brain Centre, 7491 Trondheim, Norway
| | - Emre Yaksi
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian University of Science and Technology, Olav Kyrres Gate 9, Norwegian Brain Centre, 7491 Trondheim, Norway.
| |
Collapse
|
8
|
Elucidation of the neural circuits activated by a GABA B receptor positive modulator: Relevance to anxiety. Neuropharmacology 2017; 136:129-145. [PMID: 28734870 DOI: 10.1016/j.neuropharm.2017.07.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 07/17/2017] [Accepted: 07/18/2017] [Indexed: 01/09/2023]
Abstract
Although there is much evidence for a role of GABAB receptors in the pathophysiology of anxiety, the underlying neuronal mechanisms are largely unclear. The GABAB receptor allosteric positive modulator, GS39783, exerts anxiolytic effects without interfering with GABAB-mediated modulation of body temperature, cognitive performance and locomotor activity thus offering advantages over GABAB receptor agonists. However, the precise neural circuits underlying the anxiolytic effects of GS39783 are unknown. The aim of the present study was to identify brain structures and associated neuronal circuits that are modulated by GS39783 under either basal or mild stress conditions. To this end, the expression pattern of c-Fos, a marker of neuronal activation, was examined in mice acutely treated with GS39783 under basal conditions or following a mild anxiogenic challenge induced by exposure to the Open Arm (OA) of an Elevated Plus Maze. OA exposure enhanced c-Fos expression in vehicle-treated animals in several brain regions, including the medial prefrontal cortex, lateral septum, amygdala, hippocampus, paraventricular nucleus of the hypothalamus and the periaqueductal gray (PAG). Under basal conditions, GS39783 increased c-Fos in a restricted panel of areas notably amygdala nuclei, cortical areas and PAG subregions, while it inhibited c-Fos expression in the dorsal raphe nucleus (DRN). Under stress conditions, GS39783 reversed OA-induced c-Fos expression in the granular cell layer of the dentate gyrus, no longer increased c-Fos expression in the amygdala nor reduced c-Fos expression in the DRN. These specific patterns of neural activation by GS39783 might explain the neurobiological correlates implicated in GABAB-mediated anti-anxiety effects. This article is part of the "Special Issue Dedicated to Norman G. Bowery".
Collapse
|
9
|
Regional c-Fos expression induced by peripheral oxytocin administration is prevented by the vasopressin 1A receptor antagonist SR49059. Brain Res Bull 2016; 127:208-218. [PMID: 27725169 DOI: 10.1016/j.brainresbull.2016.10.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 10/05/2016] [Accepted: 10/06/2016] [Indexed: 12/18/2022]
Abstract
Peripherally administered oxytocin induces a wide range of behavioural and physiological effects that are thought to be mediated by the oxytocin receptor (OTR). However, oxytocin also has considerable affinity for the vasopressin 1A receptor (V1AR), such that various oxytocinergic effects may in fact be mediated by the V1AR rather than the OTR. Here we used c-Fos immunohistochemistry to determine the extent to which the regional pattern of neuronal activation produced by peripheral oxytocin involves the V1AR. Male Wistar rats were administered oxytocin (1mg/kg, IP) alone, or following pre-treatment with the V1AR antagonist SR49059 (1mg/kg, IP), and were assessed for locomotor activity changes and for c-Fos expression across a number of brain regions. Oxytocin reduced the distance travelled by rats during a 70min test session, and this inhibitory behavioural effect was prevented by SR49059. Consistent with previous reports, oxytocin increased c-Fos expression in a number of brain regions. In several of these regions-the supraoptic and paraventricular (PVN) nuclei of the hypothalamus, locus coeruleus and nucleus of the solitary tract-the c-Fos response was prevented by SR49059 pre-treatment. Notably, SR49059 inhibited the c-Fos activation in oxytocin-synthesising magnocellular neurons in the PVN. However, c-Fos expression in the central amygdala to oxytocin was unaffected by SR49059. The current findings add to an increasing body of research suggesting that many of the functional effects of oxytocin may be V1AR mediated.
Collapse
|
10
|
Maitre M, Klein C, Mensah-Nyagan AG. Mechanisms for the Specific Properties of γ-Hydroxybutyrate in Brain. Med Res Rev 2016; 36:363-88. [PMID: 26739481 DOI: 10.1002/med.21382] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 11/17/2015] [Accepted: 11/25/2015] [Indexed: 12/12/2022]
Abstract
γ-Hydroxybutyrate (GHB) is both a natural brain compound with neuromodulatory properties at central GABAergic synapses (micromolar concentration range) and also a drug (Xyrem(R) ) clinically used for the treatment of various neurological symptoms (millimolar dose range). However, this drug has abuse potential and can be addictive for some patients. Here, we review the basic mechanistic role of endogenous GHB in brain as well as the properties and mechanisms of action for therapeutic clinical doses of exogenous GHB. Several hypotheses are discussed with a preference for a molecular mechanism that conciliates most of the findings available. This conciliatory model may help for the design of GHB-like drugs active at lower doses and devoid of major side effects.
Collapse
Affiliation(s)
- Michel Maitre
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, INSERM U1119, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Bâtiment 3 de la Faculté de Médecine, 11 rue Humann, 67000, Strasbourg, France
| | - Christian Klein
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, INSERM U1119, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Bâtiment 3 de la Faculté de Médecine, 11 rue Humann, 67000, Strasbourg, France
| | - Ayikoe G Mensah-Nyagan
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, INSERM U1119, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Bâtiment 3 de la Faculté de Médecine, 11 rue Humann, 67000, Strasbourg, France
| |
Collapse
|
11
|
|
12
|
Korpi ER, den Hollander B, Farooq U, Vashchinkina E, Rajkumar R, Nutt DJ, Hyytiä P, Dawe GS. Mechanisms of Action and Persistent Neuroplasticity by Drugs of Abuse. Pharmacol Rev 2015; 67:872-1004. [DOI: 10.1124/pr.115.010967] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
|
13
|
Klein C, Mathis C, Leva G, Patte-Mensah C, Cassel JC, Maitre M, Mensah-Nyagan AG. γ-Hydroxybutyrate (Xyrem) ameliorates clinical symptoms and neuropathology in a mouse model of Alzheimer's disease. Neurobiol Aging 2015; 36:832-44. [DOI: 10.1016/j.neurobiolaging.2014.10.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 10/02/2014] [Accepted: 10/07/2014] [Indexed: 10/24/2022]
|
14
|
Gamma-Hydroxybutyrate (Sodium Oxybate): From the Initial Synthesis to the Treatment of Narcolepsy–Cataplexy and Beyond. Sleep Med 2015. [DOI: 10.1007/978-1-4939-2089-1_63] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
15
|
Xu L. Leptin action in the midbrain: From reward to stress. J Chem Neuroanat 2014; 61-62:256-65. [DOI: 10.1016/j.jchemneu.2014.06.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 06/13/2014] [Accepted: 06/25/2014] [Indexed: 12/11/2022]
|
16
|
Vadovičová K. Affective and cognitive prefrontal cortex projections to the lateral habenula in humans. Front Hum Neurosci 2014; 8:819. [PMID: 25386128 PMCID: PMC4209891 DOI: 10.3389/fnhum.2014.00819] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 09/25/2014] [Indexed: 11/13/2022] Open
Abstract
Anterior insula (AI) and dorsal ACC (dACC) are known to process information about pain, loss, adversities, bad, harmful or suboptimal choices and consequences that threaten survival or well-being. Also pregenual ACC (pgACC) is linked to loss and pain, being activated by sad thoughts and regrets. Lateral habenula (LHb) is stimulated by predicted and received pain, discomfort, aversive outcome, loss. Its chronic stimulation makes us feel worse/low and gradually stops us choosing and moving for the suboptimal or punished choices, by direct and indirect (via rostromedial tegmental nucleus, RMTg) inhibition of dorsal raphe nucleus (DRN) and VTA/SNc. The response selectivity of LHb neurons suggests their cortical input from affective and cognitive evaluative regions that make expectations about bad, unpleasant or suboptimal outcomes. Based on these facts I predicted direct dACC, pgACC and AI projections to LHb, which form part of an adversity processing circuit that learns to avoid bad outcomes by suppressing dopamine and serotonin signal. To test this connectivity I used Diffusion Tensor Imaging (DTI). I found dACC, pgACC, AI and caudolateral OFC (clOFC) projections to LHb. I predicted no corticohabenular projections from the reward processing regions: medial OFC (mOFC) and ventral ACC (vACC) because both respond most strongly to good, high valued stimuli and outcomes, inducing dopamine and serotonin release. This lack of LHb projections was confirmed for vACC and likely for mOFC. The surprising findings were the corticohabenular projections from the cognitive prefrontal cortex regions, known for flexible reasoning, planning and combining whatever information are relevant for reaching current goals. I propose that the prefrontohabenular projections provide a teaching signal for value-based choice behavior, to learn to deselect, avoid or inhibit the potentially harmful, low valued or wrong choices, goals, strategies, predictions and ways of doing things, to prevent bad or suboptimal consequences.
Collapse
Affiliation(s)
- Karin Vadovičová
- Neuroradiology Unit, Department of Diagnostic Imaging Brescia, Italy
| |
Collapse
|
17
|
Hodor A, Palchykova S, Gao B, Bassetti CL. Baclofen and gamma-hydroxybutyrate differentially altered behavior, EEG activity and sleep in rats. Neuroscience 2014; 284:18-28. [PMID: 25301745 DOI: 10.1016/j.neuroscience.2014.08.061] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 08/17/2014] [Accepted: 08/27/2014] [Indexed: 12/29/2022]
Abstract
OBJECTIVES Animal and human studies have shown that sleep may have an impact on functional recovery after brain damage. Baclofen (Bac) and gamma-hydroxybutyrate (GHB) have been shown to induce physiological sleep in humans, however, their effects in rodents are unclear. The aim of this study is to characterize sleep and electroencelphalogram (EEG) after Bac and GHB administration in rats. We hypothesized that both drugs would induce physiological sleep. METHODS Adult male Sprague-Dawley rats were implanted with EEG/electromyogram (EMG) electrodes for sleep recordings. Bac (10 or 20 mg/kg), GHB (150 or 300 mg/kg) or saline were injected 1 h after light and dark onset to evaluate time of day effect of the drugs. Vigilance states and EEG spectra were quantified. RESULTS Bac and GHB induced a non-physiological state characterized by atypical behavior and an abnormal EEG pattern. After termination of this state, Bac was found to increase the duration of non-rapid eye movement (NREM) and rapid eye movement (REM) sleep (∼90 and 10 min, respectively), reduce sleep fragmentation and affect NREM sleep episode frequency and duration (p<0.05). GHB had no major effect on vigilance states. Bac drastically increased EEG power density in NREM sleep in the frequencies 1.5-6.5 and 9.5-21.5 Hz compared to saline (p<0.05), while GHB enhanced power in the 1-5-Hz frequency band and reduced it in the 7-9-Hz band. Slow-wave activity in NREM sleep was enhanced 1.5-3-fold during the first 1-2 h following termination of the non-physiological state. The magnitude of drug effects was stronger during the dark phase. CONCLUSION While both Bac and GHB induced a non-physiological resting state, only Bac facilitated and consolidated sleep, and promoted EEG delta oscillations thereafter. Hence, Bac can be considered a sleep-promoting drug and its effects on functional recovery after stroke can be evaluated both in humans and rats.
Collapse
Affiliation(s)
- A Hodor
- Center for Experimental Neurology (ZEN), Department of Neurology, Inselspital, Bern University Hospital, Switzerland.
| | - S Palchykova
- Center for Experimental Neurology (ZEN), Department of Neurology, Inselspital, Bern University Hospital, Switzerland
| | - B Gao
- Center for Experimental Neurology (ZEN), Department of Neurology, Inselspital, Bern University Hospital, Switzerland
| | - C L Bassetti
- Center for Experimental Neurology (ZEN), Department of Neurology, Inselspital, Bern University Hospital, Switzerland
| |
Collapse
|
18
|
van Nieuwenhuijzen P, McGregor I, Chebib M, Hunt G. Regional Fos-expression induced by γ-hydroxybutyrate (GHB): Comparison with γ-butyrolactone (GBL) and effects of co-administration of the GABAB antagonist SCH 50911 and putative GHB antagonist NCS-382. Neuroscience 2014; 277:700-15. [DOI: 10.1016/j.neuroscience.2014.07.056] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 06/25/2014] [Accepted: 07/01/2014] [Indexed: 10/25/2022]
|
19
|
Abstract
γ-Hydroxybutyrate (GHB) is an approved therapeutic for the excessive sleepiness and sudden loss of muscle tone (cataplexy) characteristic of narcolepsy. The mechanism of action for these therapeutic effects is hypothesized to be GABAB receptor dependent. We evaluated the effects of chronic administration of GHB and the GABAB agonist R-baclofen (R-BAC) on arousal state and cataplexy in two models of narcolepsy: orexin/ataxin-3 (Atax) and orexin/tTA; TetO diphtheria toxin mice (DTA). Mice were implanted for EEG/EMG monitoring and dosed with GHB (150 mg/kg), R-BAC (2.8 mg/kg), or vehicle (VEH) bid for 15 d-a treatment paradigm designed to model the twice nightly GHB dosing regimen used by human narcoleptics. In both models, R-BAC increased NREM sleep time, intensity, and consolidation during the light period; wake bout duration increased and cataplexy decreased during the subsequent dark period. GHB did not increase NREM sleep consolidation or duration, although NREM delta power increased in the first hour after dosing. Cataplexy decreased from baseline in 57 and 86% of mice after GHB and R-BAC, respectively, whereas cataplexy increased in 79% of the mice after VEH. At the doses tested, R-BAC suppressed cataplexy to a greater extent than GHB. These results suggest utility of R-BAC-based therapeutics for narcolepsy.
Collapse
|
20
|
GHB receptor targets in the CNS: Focus on high-affinity binding sites. Biochem Pharmacol 2014; 87:220-8. [DOI: 10.1016/j.bcp.2013.10.028] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 10/29/2013] [Accepted: 10/29/2013] [Indexed: 12/13/2022]
|
21
|
Vogensen SB, Marek A, Bay T, Wellendorph P, Kehler J, Bundgaard C, Frølund B, Pedersen MHF, Clausen RP. New synthesis and tritium labeling of a selective ligand for studying high-affinity γ-hydroxybutyrate (GHB) binding sites. J Med Chem 2013; 56:8201-5. [PMID: 24053696 DOI: 10.1021/jm4011719] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
3-Hydroxycyclopent-1-enecarboxylic acid (HOCPCA, 1) is a potent ligand for the high-affinity GHB binding sites in the CNS. An improved synthesis of 1 together with a very efficient synthesis of [(3)H]-1 is described. The radiosynthesis employs in situ generated lithium trimethoxyborotritide. Screening of 1 against different CNS targets establishes a high selectivity, and we demonstrate in vivo brain penetration. In vitro characterization of [(3)H]-1 binding shows high specificity to the high-affinity GHB binding sites.
Collapse
Affiliation(s)
- Stine B Vogensen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen , 2100 Copenhagen, Denmark
| | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Kohlmeier KA, Vardar B, Christensen MH. γ-Hydroxybutyric acid induces actions via the GABAB receptor in arousal and motor control-related nuclei: implications for therapeutic actions in behavioral state disorders. Neuroscience 2013; 248:261-77. [PMID: 23791974 DOI: 10.1016/j.neuroscience.2013.06.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Revised: 05/22/2013] [Accepted: 06/07/2013] [Indexed: 10/26/2022]
Abstract
γ-Hydroxybutyric acid (GHB) is used as an effective therapeutic for reducing the hypersomnolence and cataplexy (loss of motor control) of the sleeping disorder, narcolepsy, with an immediate pharmacologic behavioral action of inducing a natural sleep-like state. Despite its clinical use, few studies have examined the cellular actions of this drug on behavioral state-related neurons. Therefore, we monitored GHB-induced responses using calcium imaging within the laterodorsal tegmentum (LDT) and the dorsal raphe (DR), two pontine nuclei important in state and motor control. In addition, we recorded GHB-induced membrane responses using whole cell, patch clamp electrophysiology of immunohistochemically-identified principal neurons within these nuclei. GHB induced GABAB receptor-mediated rises in calcium in neurons of the LDT and the DR. However, the pattern and amplitude of calcium rises differed greatly between these two nuclei. GHB induced GABAB receptor antagonist-sensitive outward currents/hyperpolarizations in immunohistochemically-identified cholinergic LDT and serotonergic DR neurons. However, GHB had this action in a greater proportion of DR cells than LDT neurons. Further, larger inhibitory currents were induced in DR cells when compared to the amplitude of GHB-induced current in LDT-responding cells. Finally, NCS-382 and HOCPCA, a reported antagonist and agonist specific to activity at the putative GHB receptor, respectively, with no demonstrated binding at the GABAB receptor, failed to block GHB-induced effects or elicit any discernible electrophysiological action when applied alone, indicating a lack of involvement of a GHB receptor in mediating GHB actions. Taken together, our data support the conclusion that GHB may be exerting its actions on state and motor control, in part, via an acutely mediated strong inhibition of serotonergic DR neurons and a more modest inhibitory action on a smaller proportion of LDT cholinergic neurons. Given the roles played by these nuclei, these actions are consistent with acute pharmacologic effects of GHB: hypotonia and promotion of sleep, including presence of REM, a sub-state of sleep. Differences in GHB-mediated calcium suggest differential regulation of calcium-dependent processes, which may also contribute to functioning of the LDT and DR in state and motor control and the therapeutic pharmacologic actions of GHB, which develop following chronic administration. These findings add to knowledge of cellular actions of GHB and it is hoped that, combined with findings from other studies examining GHB neurotransmission, these data can contribute to development of highly targeted therapeutics at the GABAB receptor for management of human disorders presenting with alterations in motor and arousal control.
Collapse
Affiliation(s)
- K A Kohlmeier
- Department of Drug Design and Pharmacology, Faculty of Health Sciences, Universitsparken 2, University of Copenhagen, Copenhagen 2100, Denmark.
| | - B Vardar
- Department of Drug Design and Pharmacology, Faculty of Health Sciences, Universitsparken 2, University of Copenhagen, Copenhagen 2100, Denmark
| | - M H Christensen
- Department of Drug Design and Pharmacology, Faculty of Health Sciences, Universitsparken 2, University of Copenhagen, Copenhagen 2100, Denmark
| |
Collapse
|
23
|
Zanos P, Wright SR, Georgiou P, Yoo JH, Ledent C, Hourani SM, Kitchen I, Winsky-Sommerer R, Bailey A. Chronic methamphetamine treatment induces oxytocin receptor up-regulation in the amygdala and hypothalamus via an adenosine A2A receptor-independent mechanism. Pharmacol Biochem Behav 2013; 119:72-9. [PMID: 23680573 DOI: 10.1016/j.pbb.2013.05.009] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 04/30/2013] [Accepted: 05/03/2013] [Indexed: 12/12/2022]
Abstract
There is mounting evidence that the neuropeptide oxytocin is a possible candidate for the treatment of drug addiction. Oxytocin was shown to reduce methamphetamine self-administration, conditioned place-preference, hyperactivity and reinstatement in rodents, highlighting its potential for the management of methamphetamine addiction. Thus, we hypothesised that the central endogenous oxytocinergic system is dysregulated following chronic methamphetamine administration. We tested this hypothesis by examining the effect of chronic methamphetamine administration on oxytocin receptor density in mice brains with the use of quantitative receptor autoradiographic binding. Saline (4ml/kg/day, i.p.) or methamphetamine (1mg/kg/day, i.p.) was administered daily for 10 days to male, CD1 mice. Quantitative autoradiographic mapping of oxytocin receptors was carried out with the use of [(125)I]-vasotocin in brain sections of these animals. Chronic methamphetamine administration induced a region specific upregulation of oxytocin receptor density in the amygdala and hypothalamus, but not in the nucleus accumbens and caudate putamen. As there is evidence suggesting an involvement of central adenosine A2A receptors on central endogenous oxytocinergic function, we investigated whether these methamphetamine-induced oxytocinergic neuroadaptations are mediated via an A2A receptor-dependent mechanism. To test this hypothesis, autoradiographic oxytocin receptor binding was carried out in brain sections of male CD1 mice lacking A2A receptors which were chronically treated with methamphetamine (1mg/kg/day, i.p. for 10 days) or saline. Similar to wild-type animals, chronic methamphetamine administration induced a region-specific upregulation of oxytocin receptor binding in the amygdala and hypothalamus of A2A receptor knockout mice and no genotype effect was observed. These results indicate that chronic methamphetamine use can induce profound neuroadaptations of the oxytocinergic receptor system in brain regions associated with stress, emotionality and social bonding and that these neuroadaptations are independent on the presence of A2A receptors. These results may at least partly explain some of the behavioural consequences of chronic methamphetamine use.
Collapse
Affiliation(s)
- Panos Zanos
- Sleep, Chronobiology & Addiction Group, Department of Biochemistry & Physiology, Faculty of Health and Medical Sciences, University of Surrey, Guildford, GU2 7XH, Surrey, UK
| | - Sherie R Wright
- Sleep, Chronobiology & Addiction Group, Department of Biochemistry & Physiology, Faculty of Health and Medical Sciences, University of Surrey, Guildford, GU2 7XH, Surrey, UK
| | - Polymnia Georgiou
- Sleep, Chronobiology & Addiction Group, Department of Biochemistry & Physiology, Faculty of Health and Medical Sciences, University of Surrey, Guildford, GU2 7XH, Surrey, UK
| | - Ji Hoon Yoo
- Sleep, Chronobiology & Addiction Group, Department of Biochemistry & Physiology, Faculty of Health and Medical Sciences, University of Surrey, Guildford, GU2 7XH, Surrey, UK
| | - Catherine Ledent
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire, Université Libre de Bruxelles, B-1070, Belgium
| | - Susanna M Hourani
- Sleep, Chronobiology & Addiction Group, Department of Biochemistry & Physiology, Faculty of Health and Medical Sciences, University of Surrey, Guildford, GU2 7XH, Surrey, UK
| | - Ian Kitchen
- Sleep, Chronobiology & Addiction Group, Department of Biochemistry & Physiology, Faculty of Health and Medical Sciences, University of Surrey, Guildford, GU2 7XH, Surrey, UK
| | - Raphaelle Winsky-Sommerer
- Sleep, Chronobiology & Addiction Group, Department of Biochemistry & Physiology, Faculty of Health and Medical Sciences, University of Surrey, Guildford, GU2 7XH, Surrey, UK
| | - Alexis Bailey
- Sleep, Chronobiology & Addiction Group, Department of Biochemistry & Physiology, Faculty of Health and Medical Sciences, University of Surrey, Guildford, GU2 7XH, Surrey, UK.
| |
Collapse
|
24
|
Kimura EH, De Oliveira LB, Menani JV, Callera JC. Baclofen into the lateral parabrachial nucleus induces hypertonic sodium chloride intake during cell dehydration. Behav Brain Funct 2013; 9:17. [PMID: 23642235 PMCID: PMC3679877 DOI: 10.1186/1744-9081-9-17] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Accepted: 04/23/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Activation of GABA(B) receptors with baclofen into the lateral parabrachial nucleus (LPBN) induces ingestion of water and 0.3 M NaCl in fluid replete rats. However, up to now, no study has investigated the effects of baclofen injected alone or combined with GABA(B) receptor antagonist into the LPBN on water and 0.3 M NaCl intake in rats with increased plasma osmolarity (rats treated with an intragastric load of 2 M NaCl). Male Wistar rats with stainless steel cannulas implanted bilaterally into the LPBN were used. RESULTS In fluid replete rats, baclofen (0.5 nmol/0.2 μl), bilaterally injected into the LPBN, induced ingestion of 0.3 M NaCl (14.3 ± 4.1 vs. saline: 0.2 ± 0.2 ml/210 min) and water (7.1 ± 2.9 vs. saline: 0.6 ± 0.5 ml/210 min). In cell-dehydrated rats, bilateral injections of baclofen (0.5 and 1.0 nmol/0.2 μl) into the LPBN induced an increase of 0.3 M NaCl intake (15.6 ± 5.7 and 21.5 ± 3.5 ml/210 min, respectively, vs. saline: 1.7 ± 0.8 ml/210 min) and an early inhibition of water intake (3.5 ± 1.4 and 6.7 ± 2.1 ml/150 min, respectively, vs. saline: 9.2 ± 1.4 ml/150 min). The pretreatment of the LPBN with 2-hydroxysaclofen (GABA(B) antagonist, 5 nmol/0.2 μl) potentiated the effect of baclofen on 0.3 M NaCl intake in the first 90 min of test and did not modify the inhibition of water intake induced by baclofen in cell-dehydrated rats. Baclofen injected into the LPBN did not affect blood pressure and heart rate. CONCLUSIONS Thus, injection of baclofen into the LPBN in cell-dehydrated rats induced ingestion of 0.3 M NaCl and inhibition of water intake, suggesting that even in a hyperosmotic situation, the blockade of LPBN inhibitory mechanisms with baclofen is enough to drive rats to drink hypertonic NaCl, an effect independent of changes in blood pressure.
Collapse
Affiliation(s)
- Everton H Kimura
- Department of Basic Sciences, School of Dentistry, UNESP - Univ. Estadual Paulista, Rodovia Marechal Rondom, km 527, Araçatuba, São Paulo 16018-805, Brazil
| | | | | | | |
Collapse
|
25
|
Differential development of tolerance to the functional and behavioral effects of repeated baclofen treatment in rats. Pharmacol Biochem Behav 2013; 106:27-32. [PMID: 23500188 DOI: 10.1016/j.pbb.2013.03.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 02/27/2013] [Accepted: 03/02/2013] [Indexed: 11/21/2022]
Abstract
Baclofen, a gamma-aminobutyric acid (GABA)B receptor agonist, has been used clinically to treat muscle spasticity, rigidity and pain. More recently, interest in the use of baclofen as an addiction medicine has grown, with promising preclinical cocaine and amphetamine data and demonstrated clinical benefit from alcohol and nicotine studies. Few preclinical investigations, however, have utilized chronic dosing of baclofen, which is important given that tolerance can occur to many of its effects. Thus the question of whether chronic treatment of baclofen maintains the efficacy of acute doses is imperative. The neural substrates that underlie the effects of baclofen, particularly those after chronic treatment, are also not known. In the present study, therefore, rats were treated with either a) vehicle, b) acute baclofen (5 mg/kg) or c) chronic baclofen (5 mg/kg, t.i.d. for 5 days). The effects of acute and chronic baclofen administration, compared to vehicle, were assessed using locomotor activity and changes in brain glucose metabolism (a measure of functional brain activity). Acute baclofen significantly reduced locomotor activity (horizontal and total distance traveled), while chronic baclofen failed to affect locomotor activity. Acute baclofen resulted in significantly lower rates of local cerebral glucose utilization throughout many areas of the brain, including the prefrontal cortex, caudate putamen, septum and hippocampus. The majority of these functional effects, with the exception of the caudate putamen and septum, were absent in animals chronically treated with baclofen. Despite the tolerance to the locomotor and functional effects of baclofen following repeated treatment, these persistent effects on functional activity in the caudate putamen and septum may provide insights into the way in which baclofen alters the reinforcing effects of abused substances such as cocaine, alcohol, and methamphetamine both in humans and animal models.
Collapse
|
26
|
Peters S, Slattery DA, Flor PJ, Neumann ID, Reber SO. Differential effects of baclofen and oxytocin on the increased ethanol consumption following chronic psychosocial stress in mice. Addict Biol 2013; 18:66-77. [PMID: 23126471 DOI: 10.1111/adb.12001] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Chronic stress is known to enhance the susceptibility for addiction disorders including alcoholism. While these findings have been recapitulated in animal models, the majority of these studies have utilized non-social rather than social stress paradigms; the latter of which are believed to be more relevant to the human situation. Therefore, the major aim of this study was to investigate, if 14 days of chronic subordinate colony housing (CSC), a pre-clinically validated psychosocial stress paradigm relevant for human psychiatric and somatic disorders, enhances ethanol (EtOH) consumption in male mice. To assess this, we employed the well-established two-bottle free-choice paradigm where mice were given access to water and 2, 4, 6 and 8% EtOH solutions (with the concentrations increasing each fourth day) following termination of the stress procedure. After 14 days of CSC, stressed mice consumed significantly more EtOH at all concentrations tested and displayed increased EtOH preference at concentrations of 6 and 8%. This effect was not due to an altered taste preference in CSC mice as assessed by saccharine- and quinine-preference tests, but was accompanied by increased anxiety-related behavior. Systemic administration of baclofen (2.5 mg/kg) or oxytocin (OXT; 10 mg/kg) reduced the EtOH intake in single housed control (baclofen, OXT) and CSC (baclofen) mice, whereas intracerebroventricular OXT (0.5 μg/2 μl) was ineffective in both groups. Taken together, these results suggest that (i) chronic psychosocial stress enhances EtOH consumption, and (ii) baclofen and OXT differentially affect EtOH intake in mice.
Collapse
Affiliation(s)
- Sebastian Peters
- Department of Behavioural and Molecular Neurobiology; University of Regensburg; Regensburg; Germany
| | - David A. Slattery
- Department of Behavioural and Molecular Neurobiology; University of Regensburg; Regensburg; Germany
| | - Peter J. Flor
- Department of Behavioural and Molecular Neurobiology; University of Regensburg; Regensburg; Germany
| | - Inga D. Neumann
- Department of Behavioural and Molecular Neurobiology; University of Regensburg; Regensburg; Germany
| | - Stefan O. Reber
- Department of Behavioural and Molecular Neurobiology; University of Regensburg; Regensburg; Germany
| |
Collapse
|
27
|
Absalom N, Eghorn LF, Villumsen IS, Karim N, Bay T, Olsen JV, Knudsen GM, Bräuner-Osborne H, Frølund B, Clausen RP, Chebib M, Wellendorph P. α4βδ GABA(A) receptors are high-affinity targets for γ-hydroxybutyric acid (GHB). Proc Natl Acad Sci U S A 2012; 109:13404-9. [PMID: 22753476 PMCID: PMC3421209 DOI: 10.1073/pnas.1204376109] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
γ-Hydroxybutyric acid (GHB) binding to brain-specific high-affinity sites is well-established and proposed to explain both physiological and pharmacological actions. However, the mechanistic links between these lines of data are unknown. To identify molecular targets for specific GHB high-affinity binding, we undertook photolinking studies combined with proteomic analyses and identified several GABA(A) receptor subunits as possible candidates. A subsequent functional screening of various recombinant GABA(A) receptors in Xenopus laevis oocytes using the two-electrode voltage clamp technique showed GHB to be a partial agonist at αβδ- but not αβγ-receptors, proving that the δ-subunit is essential for potency and efficacy. GHB showed preference for α4 over α(1,2,6)-subunits and preferably activated α4β1δ (EC(50) = 140 nM) over α4β(2/3)δ (EC(50) = 8.41/1.03 mM). Introduction of a mutation, α4F71L, in α4β1(δ)-receptors completely abolished GHB but not GABA function, indicating nonidentical binding sites. Radioligand binding studies using the specific GHB radioligand [(3)H](E,RS)-(6,7,8,9-tetrahydro-5-hydroxy-5H-benzocyclohept-6-ylidene)acetic acid showed a 39% reduction (P = 0.0056) in the number of binding sites in α4 KO brain tissue compared with WT controls, corroborating the direct involvement of the α4-subunit in high-affinity GHB binding. Our data link specific GHB forebrain binding sites with α4-containing GABA(A) receptors and postulate a role for extrasynaptic α4δ-containing GABA(A) receptors in GHB pharmacology and physiology. This finding will aid in elucidating the molecular mechanisms behind the proposed function of GHB as a neurotransmitter and its unique therapeutic effects in narcolepsy and alcoholism.
Collapse
Affiliation(s)
- Nathan Absalom
- Faculty of Pharmacy A15, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Laura F. Eghorn
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Inge S. Villumsen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Nasiara Karim
- Faculty of Pharmacy A15, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Tina Bay
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Jesper V. Olsen
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; and
| | - Gitte M. Knudsen
- Neurobiology Research Unit and Center for Integrated Molecular Brain Imaging (Cimbi), Rigshospitalet and University of Copenhagen, 2100 Copenhagen, Denmark
| | - Hans Bräuner-Osborne
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Bente Frølund
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Rasmus P. Clausen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Mary Chebib
- Faculty of Pharmacy A15, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Petrine Wellendorph
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark
| |
Collapse
|
28
|
Hicks C, Jorgensen W, Brown C, Fardell J, Koehbach J, Gruber CW, Kassiou M, Hunt GE, McGregor IS. The nonpeptide oxytocin receptor agonist WAY 267,464: receptor-binding profile, prosocial effects and distribution of c-Fos expression in adolescent rats. J Neuroendocrinol 2012; 24:1012-29. [PMID: 22420322 PMCID: PMC3399775 DOI: 10.1111/j.1365-2826.2012.02311.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Previous research suggests that the nonpeptide oxytocin receptor (OTR) agonist WAY 267,464 may only partly mimic the effects of oxytocin in rodents. The present study further explored these differences and related them to OTR and vasopressin 1a receptor (V(1a) R) pharmacology and regional patterns of c-Fos expression. Binding data for WAY 267,464 and oxytocin were obtained by displacement binding assays on cellular membranes, while functional receptor data were generated by luciferase reporter assays. For behavioural testing, adolescent rats were tested in a social preference paradigm, the elevated plus-maze (EPM) and for locomotor activity changes following WAY 267,464 (10 and 100 mg/kg, i.p.) or oxytocin (0.1 and 1 mg/kg, i.p.). The higher doses were also examined for their effects on regional c-Fos expression. Results showed that WAY 267,464 had higher affinity (K(i) ) at the V(1a) R than the OTR (113 versus 978 nm). However, it had no functional response at the V(1a) R and only a weak functional effect (EC(50) ) at the OTR (881 nm). This suggests WAY 267,464 is an OTR agonist with weak affinity and a possible V(1a) R antagonist. Oxytocin showed high binding at the OTR (1.0 nm) and V(1a) R (503 nm), with a functional EC(50) of 9.0 and 59.7 nm, respectively, indicating it is a potent OTR agonist and full V(1a) R agonist. WAY 267,464 (100 mg/kg), but not oxytocin, significantly increased the proportion of time spent with a live rat, over a dummy rat, in the social preference test. Neither compound affected EPM behaviour, whereas the higher doses of WAY 267,464 and oxytocin suppressed locomotor activity. WAY 267,464 and oxytocin produced similar c-Fos expression in the paraventricular hypothalamic nucleus, central amygdala, lateral parabrachial nucleus and nucleus of the solitary tract, suggesting a commonality of action at the OTR with the differential doses employed. However, WAY 267,464 caused greater c-Fos expression in the medial amygdala and the supraoptic nucleus than oxytocin, and lesser effects in the locus coeruleus. Overall, our results confirm the differential effects of WAY 267,464 and oxytocin and suggest that this may reflect contrasting actions of WAY 267,464 and oxytocin at the V(1a) R. Antagonism of the V(1a) R by WAY 267,464 could underlie some of the prosocial effects of this drug either through a direct action or through disinhibition of oxytocin circuitry that is subject to vasopressin inhibitory influences.
Collapse
Affiliation(s)
- C. Hicks
- School of Psychology, Brennan MacCallum Building, University of Sydney, Sydney, Australia
| | - W. Jorgensen
- School of Chemistry, University of Sydney, Sydney, Australia
- Brain and Mind Research Institute, University of Sydney, Sydney, Australia
| | - C. Brown
- Brain and Mind Research Institute, University of Sydney, Sydney, Australia
| | - J. Fardell
- School of Psychology, Brennan MacCallum Building, University of Sydney, Sydney, Australia
| | - J. Koehbach
- Medical University of Vienna, Centre for Physiology and Pharmacology, Vienna, Austria
| | - C. W. Gruber
- Medical University of Vienna, Centre for Physiology and Pharmacology, Vienna, Austria
| | - M. Kassiou
- School of Chemistry, University of Sydney, Sydney, Australia
- Brain and Mind Research Institute, University of Sydney, Sydney, Australia
- Discipline of Medical Radiation Sciences, University of Sydney, Sydney, Australia
| | - G. E. Hunt
- Discipline of Psychiatry, Sydney Medical School, University of Sydney, Concord Hospital, Sydney, Australia
| | - I. S. McGregor
- School of Psychology, Brennan MacCallum Building, University of Sydney, Sydney, Australia
| |
Collapse
|
29
|
McGregor IS, Bowen MT. Breaking the loop: oxytocin as a potential treatment for drug addiction. Horm Behav 2012; 61:331-9. [PMID: 22198308 DOI: 10.1016/j.yhbeh.2011.12.001] [Citation(s) in RCA: 213] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Revised: 12/04/2011] [Accepted: 12/05/2011] [Indexed: 12/18/2022]
Abstract
Drug use typically occurs within a social context, and social factors play an important role in the initiation, maintenance and recovery from addictions. There is now accumulating evidence of an interaction between the neural substrates of affiliative behavior and those of drug reward, with a role for brain oxytocin systems in modulating acute and long-term drug effects. Early research in this field indicated that exogenous oxytocin administration can prevent development of tolerance to ethanol and opiates, the induction of stereotyped, hyperactive behavior by stimulants, and the withdrawal symptoms associated with sudden abstinence from drugs and alcohol. Additionally, stimulation of endogenous oxytocin systems is a key neurochemical substrate underlying the prosocial and empathogenic effects of party drugs such as MDMA (Ecstasy) and GHB (Fantasy). Brain oxytocin systems exhibit profound neuroplasticity and undergo major neuroadaptations as a result of drug exposure. Many drugs, including cocaine, opiates, alcohol, cannabis, MDMA and GHB cause long-term changes in markers of oxytocin function and this may be linked to enduring deficits in social behavior that are commonly observed in laboratory animals repeatedly exposed to these drugs. Very recent preclinical studies have illustrated a remarkable ability of exogenously delivered oxytocin to inhibit stimulant and alcohol self-administration, to alter associated drug-induced changes in dopamine, glutamate and Fos expression in cortical and basal ganglia sites, and to prevent stress and priming-induced relapse to drug seeking. Oxytocin therefore has fascinating potential to reverse the corrosive effects of long-term drugs abuse on social behavior and to perhaps inoculate against future vulnerability to addictive disorders. The results of clinical studies examining intranasal oxytocin effects in humans with drug use disorders are eagerly awaited. This article is part of a Special Issue entitled Oxytocin, Vasopressin, and Social Behavior.
Collapse
Affiliation(s)
- Iain S McGregor
- School of Psychology, University of Sydney, NSW 2006, Australia.
| | | |
Collapse
|
30
|
Cornish J, Hunt G, Robins L, McGregor I. Regional c-Fos and FosB/ΔFosB expression associated with chronic methamphetamine self-administration and methamphetamine-seeking behavior in rats. Neuroscience 2012; 206:100-14. [DOI: 10.1016/j.neuroscience.2012.01.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Revised: 12/08/2011] [Accepted: 01/04/2012] [Indexed: 10/14/2022]
|
31
|
Motbey CP, Hunt GE, Bowen MT, Artiss S, McGregor IS. Mephedrone (4-methylmethcathinone, 'meow'): acute behavioural effects and distribution of Fos expression in adolescent rats. Addict Biol 2012; 17:409-22. [PMID: 21995495 DOI: 10.1111/j.1369-1600.2011.00384.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Mephedrone (4-methylmethcathinone) is a novel recreational drug that has rapidly increased in popularity in recent years. Users report mephedrone as having the stimulant-like qualities of methamphetamine and cocaine, combined with the prosocial, entactogenic effects of 3,4-methylenedioxymethamphetamine (MDMA). Anecdotal and case study reports indicate that mephedrone may have the potential to engender compulsive patterns of use as well as toxicity in overdose. However, there have been almost no neuropharmacological investigations of the drug up to this point. Here we examined the effects of two different mephedrone doses [15 and 30 mg/kg, intraperitoneal (IP)] relative to the well-known stimulant methamphetamine (2 mg/kg IP) in adolescent rats. Rats were injected, assessed for locomotor activity for 60 minutes and then tested in a 10-minute social preference test (measuring time spent in close proximity to a real rat versus a dummy rat). Their brains were then processed using Fos immunohistochemistry to determine patterns of brain activation. Results showed that mephedrone caused profound locomotor hyperactivity at both dose levels while tending to reduce social preference. Patterns of Fos expression with mephedrone resembled a combination of those observed with methamphetamine and MDMA, with particularly strong Fos expression in the cortex, dorsal and ventral striatum, ventral tegmental area (typical of both MDMA and methamphetamine) and supraoptic nucleus (typical of MDMA). These results demonstrate for the first time the powerful stimulant effects of mephedrone in animal models and its capacity to activate mesolimbic regions. These results also provide some empirical basis to user reports that mephedrone subjectively resembles a MDMA/methamphetamine hybrid.
Collapse
Affiliation(s)
- Craig P Motbey
- School of Psychology, University of Sydney, NSW 2006, Australia
| | | | | | | | | |
Collapse
|
32
|
Mohamed WM, Hamida SB, Cassel JC, de Vasconcelos AP, Jones BC. MDMA: Interactions with other psychoactive drugs. Pharmacol Biochem Behav 2011; 99:759-74. [DOI: 10.1016/j.pbb.2011.06.032] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2010] [Revised: 05/10/2011] [Accepted: 06/28/2011] [Indexed: 10/18/2022]
|
33
|
Kozicz T, Bittencourt JC, May PJ, Reiner A, Gamlin PDR, Palkovits M, Horn AKE, Toledo CAB, Ryabinin AE. The Edinger-Westphal nucleus: a historical, structural, and functional perspective on a dichotomous terminology. J Comp Neurol 2011; 519:1413-34. [PMID: 21452224 DOI: 10.1002/cne.22580] [Citation(s) in RCA: 152] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The eponymous term nucleus of Edinger-Westphal (EW) has come to be used to describe two juxtaposed and somewhat intermingled cell groups of the midbrain that differ dramatically in their connectivity and neurochemistry. On one hand, the classically defined EW is the part of the oculomotor complex that is the source of the parasympathetic preganglionic motoneuron input to the ciliary ganglion (CG), through which it controls pupil constriction and lens accommodation. On the other hand, EW is applied to a population of centrally projecting neurons involved in sympathetic, consumptive, and stress-related functions. This terminology problem arose because the name EW has historically been applied to the most prominent cell collection above or between the somatic oculomotor nuclei (III), an assumption based on the known location of the preganglionic motoneurons in monkeys. However, in many mammals, the nucleus designated as EW is not made up of cholinergic, preganglionic motoneurons supplying the CG and instead contains neurons using peptides, such as urocortin 1, with diverse central projections. As a result, the literature has become increasingly confusing. To resolve this problem, we suggest that the term EW be supplemented with terminology based on connectivity. Specifically, we recommend that 1) the cholinergic, preganglionic neurons supplying the CG be termed the Edinger-Westphal preganglionic (EWpg) population and 2) the centrally projecting, peptidergic neurons be termed the Edinger-Westphal centrally projecting (EWcp) population. The history of this nomenclature problem and the rationale for our solutions are discussed in this review.
Collapse
Affiliation(s)
- Tamás Kozicz
- Department of Cellular Animal Physiology, Donders Institute for Brain Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands.
| | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Luppi PH, Clément O, Sapin E, Gervasoni D, Peyron C, Léger L, Salvert D, Fort P. The neuronal network responsible for paradoxical sleep and its dysfunctions causing narcolepsy and rapid eye movement (REM) behavior disorder. Sleep Med Rev 2011; 15:153-63. [PMID: 21115377 DOI: 10.1016/j.smrv.2010.08.002] [Citation(s) in RCA: 186] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2010] [Revised: 08/11/2010] [Accepted: 08/11/2010] [Indexed: 02/02/2023]
Affiliation(s)
- Pierre-Hervé Luppi
- UMR5167 CNRS, Institut Fédératif des Neurosciences de Lyon (IFR 19), Univ Lyon 1, Université de Lyon, Lyon, France.
| | | | | | | | | | | | | | | |
Collapse
|
35
|
|
36
|
The habenula: from stress evasion to value-based decision-making. Nat Rev Neurosci 2011; 11:503-13. [PMID: 20559337 DOI: 10.1038/nrn2866] [Citation(s) in RCA: 680] [Impact Index Per Article: 52.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Surviving in a world with hidden rewards and dangers requires choosing the appropriate behaviours. Recent discoveries indicate that the habenula plays a prominent part in such behavioural choice through its effects on neuromodulator systems, in particular the dopamine and serotonin systems. By inhibiting dopamine-releasing neurons, habenula activation leads to the suppression of motor behaviour when an animal fails to obtain a reward or anticipates an aversive outcome. Moreover, the habenula is involved in behavioural responses to pain, stress, anxiety, sleep and reward, and its dysfunction is associated with depression, schizophrenia and drug-induced psychosis. As a highly conserved structure in the brain, the habenula provides a fundamental mechanism for both survival and decision-making.
Collapse
|
37
|
|
38
|
Residual social, memory and oxytocin-related changes in rats following repeated exposure to γ-hydroxybutyrate (GHB), 3,4-methylenedioxymethamphetamine (MDMA) or their combination. Psychopharmacology (Berl) 2010; 212:663-74. [PMID: 20730418 DOI: 10.1007/s00213-010-1986-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Accepted: 08/06/2010] [Indexed: 10/19/2022]
Abstract
RATIONALE There has been little investigation of the possible lasting adverse effects of γ-hydroxybutyrate (GHB). OBJECTIVES This study aims to study whether GHB produces residual adverse effects on memory and social behaviour in rats and lasting changes in brain monoamines and oxytocin-related gene expression. METHODS Rats received daily intraperitoneal injections of GHB (500 mg/kg), methylenedioxymethamphetamine (MDMA; 5 mg/kg) or their combination (GHB/MDMA) over ten consecutive days. Locomotor activity and body weight were assessed during the dosing period and withdrawal-related anxiety was assessed 24 h after drug cessation. After a washout of 4 weeks, rats were tested on the emergence, social interaction, and object recognition tasks over a 2-week period. Monoamine levels in cortex and striatum, and hypothalamic oxytocin and oxytocin receptor mRNA, were then assessed. RESULTS MDMA and GHB/MDMA caused modest sensitization of locomotor activity over time, while sedative effects of GHB diminished with repeated exposure. GHB-treated rats showed reduced social interaction 24 h after the final dose, indicating GHB withdrawal-induced anxiety. All drug-treated groups displayed residual deficits in social interaction and object recognition. No changes in monoamine levels were detected 8 weeks post-drug. However, MDMA pre-exposure increased hypothalamic oxytocin mRNA while GHB pre-exposure upregulated oxytocin receptor mRNA. GHB/MDMA pre-exposure caused intermediate changes in both of these measures. CONCLUSIONS GHB treatment caused residual impairments in memory and social behaviour and increases in anxiety, paralleling the lasting adverse effects of MDMA. Both drugs caused lasting neuroadaptations in brain oxytocin systems and this may be related to the long-term social interaction deficiencies caused by both drugs.
Collapse
|
39
|
Differential effects of GABAB receptor subtypes, {gamma}-hydroxybutyric Acid, and Baclofen on EEG activity and sleep regulation. J Neurosci 2010; 30:14194-204. [PMID: 20962240 DOI: 10.1523/jneurosci.3145-10.2010] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The role of GABA(B) receptors in sleep is still poorly understood. GHB (γ-hydroxybutyric acid) targets these receptors and is the only drug approved to treat the sleep disorder narcolepsy. GABA(B) receptors are obligate dimers comprised of the GABA(B2) subunit and either one of the two GABA(B1) subunit isoforms, GABA(B1a) and GABA(B1b). To better understand the role of GABA(B) receptors in sleep regulation, we performed electroencephalogram (EEG) recordings in mice devoid of functional GABA(B) receptors (1(-/-) and 2(-/-)) or lacking one of the subunit 1 isoforms (1a(-/-) and 1b(-/-)). The distribution of sleep over the day was profoundly altered in 1(-/-) and 2(-/-) mice, suggesting a role for GABA(B) receptors in the circadian organization of sleep. Several other sleep and EEG phenotypes pointed to a more prominent role for GABA(B1a) compared with the GABA(B1b) isoform. Moreover, we found that GABA(B1a) protects against the spontaneous seizure activity observed in 1(-/-) and 2(-/-) mice. We also evaluated the effects of the GHB-prodrug GBL (γ-butyrolactone) and of baclofen (BAC), a high-affinity GABA(B) receptor agonist. Both drugs induced a state distinct from physiological sleep that was not observed in 1(-/-) and 2(-/-) mice. Subsequent sleep was not affected by GBL whereas BAC was followed by a delayed hypersomnia even in 1(-/-) and 2(-/-) mice. The differential effects of GBL and BAC might be attributed to differences in GABA(B)-receptor affinity. These results also indicate that all GBL effects are mediated through GABA(B) receptors, although these receptors do not seem to be involved in mediating the BAC-induced hypersomnia.
Collapse
|
40
|
Carson DS, Hunt GE, Guastella AJ, Barber L, Cornish JL, Arnold JC, Boucher AA, McGregor IS. Systemically administered oxytocin decreases methamphetamine activation of the subthalamic nucleus and accumbens core and stimulates oxytocinergic neurons in the hypothalamus. Addict Biol 2010; 15:448-63. [PMID: 20731630 DOI: 10.1111/j.1369-1600.2010.00247.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Recent preclinical evidence indicates that the neuropeptide oxytocin may have potential in the treatment of drug dependence and drug withdrawal. Oxytocin reduces methamphetamine self-administration, conditioned place preference and hyperactivity in rodents. However, it is unclear how oxytocin acts in the brain to produce such effects. The present study examined how patterns of neural activation produced by methamphetamine were modified by co-administered oxytocin. Male Sprague-Dawley rats were pretreated with either 2 mg/kg oxytocin (IP) or saline and then injected with either 2 mg/kg methamphetamine (IP) or saline. After injection, locomotor activity was measured for 80 minutes prior to perfusion. As in previous studies, co-administered oxytocin significantly reduced methamphetamine-induced behaviors. Strikingly, oxytocin significantly reduced methamphetamine-induced Fos expression in two regions of the basal ganglia: the subthalamic nucleus and the nucleus accumbens core. The subthalamic nucleus is of particular interest given emerging evidence for this structure in compulsive, addiction-relevant behaviors. When administered alone, oxytocin increased Fos expression in several regions, most notably in the oxytocin-synthesizing neurons of the supraoptic nucleus and paraventricular nucleus of the hypothalamus. This provides new evidence for central actions of peripheral oxytocin and suggests a self-stimulation effect of exogenous oxytocin on its own hypothalamic circuitry. Overall, these results give further insight into the way in which oxytocin might moderate compulsive behaviors and demonstrate the capacity of peripherally administered oxytocin to induce widespread central effects.
Collapse
Affiliation(s)
- Dean S Carson
- Brain & Mind Research Institute, University of Sydney, NSW, Australia
| | | | | | | | | | | | | | | |
Collapse
|
41
|
van Nieuwenhuijzen PS, Kashem MA, Matsumoto I, Hunt GE, McGregor IS. A long hangover from party drugs: Residual proteomic changes in the hippocampus of rats 8 weeks after γ-hydroxybutyrate (GHB), 3,4-methylenedioxymethamphetamine (MDMA) or their combination. Neurochem Int 2010; 56:871-7. [DOI: 10.1016/j.neuint.2010.03.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Accepted: 03/05/2010] [Indexed: 10/19/2022]
|
42
|
Bortolato M, Frau R, Orrù M, Fà M, Dessì C, Puligheddu M, Barberini L, Pillolla G, Polizzi L, Santoni F, Mereu G, Marrosu F. GABAB receptor activation exacerbates spontaneous spike-and-wave discharges in DBA/2J mice. Seizure 2010; 19:226-31. [DOI: 10.1016/j.seizure.2010.02.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2009] [Revised: 02/13/2010] [Accepted: 02/19/2010] [Indexed: 10/19/2022] Open
|
43
|
Kemmel V, Klein C, Dembélé D, Jost B, Taleb O, Aunis D, Mensah-Nyagan AG, Maitre M. A single acute pharmacological dose of γ-hydroxybutyrate modifies multiple gene expression patterns in rat hippocampus and frontal cortex. Physiol Genomics 2010; 41:146-60. [PMID: 20103696 DOI: 10.1152/physiolgenomics.00208.2009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
γ-Hydroxybutyrate (GHB) is a natural brain neuromodulator that has its own enzymatic machinery for synthesis and degradation, release, and transport systems and several receptors that belong to the G protein-coupled receptor (GPCR) family. Targeting of this system with exogenous GHB is used in therapy to induce sleep and anesthesia and to reduce alcohol withdrawal syndrome. GHB is also popular as a recreational drug for its anxiolytic and mild euphoric effects. However, in both cases, GHB must be administered at high doses in order to maintain GHB concentrations in brain of ∼800-1,000 μM. These high concentrations are thought to be necessary for interactions with low-affinity sites on GABA(B) receptor, but the molecular targets and cellular mechanisms modulated by GHB remain poorly characterized. Therefore, to provide new insights into the elucidation of GHB mechanisms of action and open new tracks for future investigations, we explored changes of GHB-induced transcriptomes in rat hippocampus and prefrontal cortex by using DNA microarray studies. We demonstrate that a single acute anesthetic dose of 1 g/kg GHB alters a large number of genes, 121 in hippocampus and 53 in prefrontal cortex; 16 genes were modified simultaneously in both brain regions. In terms of molecular functions, the majority of modified genes coded for proteins or nucleotide binding sites. In terms of Gene Ontology (GO) functional categories, the largest groups were involved in metabolic processing for hippocampal genes and in biological regulation for prefrontal cortex genes. The majority of genes modified in both structures were implicated in cell communication processes. Western blot and immunohistochemical studies carried out on eight selected proteins confirmed the microarray findings.
Collapse
Affiliation(s)
- Véronique Kemmel
- Equipe Stéroïdes, Neuromodulateurs et Neuropathologies, EA 4438, Faculté de Médecine, 67085 Strasbourg, France.
| | | | | | | | | | | | | | | |
Collapse
|
44
|
van Nieuwenhuijzen PS, McGregor IS. Sedative and hypothermic effects of gamma-hydroxybutyrate (GHB) in rats alone and in combination with other drugs: assessment using biotelemetry. Drug Alcohol Depend 2009; 103:137-47. [PMID: 19446408 DOI: 10.1016/j.drugalcdep.2009.03.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2008] [Revised: 01/22/2009] [Accepted: 03/05/2009] [Indexed: 11/19/2022]
Abstract
The recreational drug gamma-hydroxybutyrate (GHB) has euphoric effects and can induce sedation and body temperature changes. GHB is frequently combined with other recreational drugs although these interactions are not well characterised. The present study used biotelemetry to provide a fine-grained analysis of the effects of GHB on body temperature and locomotor activity in freely moving rats, and investigated interactions between GHB and 3,4-methylenedioxymethamphetamine (MDMA), methamphetamine (METH) and various antagonist drugs. GHB (1000mg/kg) caused profound sedation for more than 2h and a complex triphasic effect on body temperature: an initial hypothermia (5-40min), followed by hyperthermia (40-140min), followed again by hypothermia (140-360min). A lower GHB dose (500mg/kg) also caused sedation but only a hypothermic effect that lasted up to 6h. The dopamine D(1) receptor antagonist SCH 23390 (1mg/kg), the opioid antagonist naltrexone (1mg/kg), the benzodiazepine antagonist flumazenil (10mg/kg), and the 5-HT(2A/2C) receptor antagonist ritanserin (1mg/kg) did not prevent the overall sedative or body temperature effects of GHB (1000mg/kg). However the GABA(B) antagonist SCH 50911 (50mg/kg) prevented the hyperthermia induced by GHB (1000mg/kg). Repeated daily administration of GHB (1000mg/kg) produced tolerance to the sedative and hyperthermic effects of the drug and cross-tolerance to the sedative effects of the GABA(B) receptor agonist baclofen (10mg/kg). A high ambient temperature of 28 degrees C prevented the hypothermia obtained with GHB (500mg/kg) at 20 degrees C, while GHB (500mg/kg) reduced the hyperthermia and hyperactivity produced by co-administered doses of MDMA (5mg/kg) or METH (1mg/kg) at 28 degrees C. These results further confirm a role for GABA(B) receptors in the hypothermic and sedative effects of GHB and show an interaction between GHB and MDMA, and GHB and METH, that may be relevant to the experience of recreational users who mix these drugs.
Collapse
|
45
|
Differential sensitivity of the perioculomotor urocortin-containing neurons to ethanol, psychostimulants and stress in mice and rats. Neuroscience 2009; 160:115-25. [PMID: 19248818 DOI: 10.1016/j.neuroscience.2009.02.030] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2008] [Revised: 02/07/2009] [Accepted: 02/10/2009] [Indexed: 11/22/2022]
Abstract
The perioculomotor urocortin-containing population of neurons (pIIIu: otherwise known as the non-preganglionic Edinger-Westphal nucleus) is sensitive to alcohol and is involved in the regulation of alcohol intake. A recent study indicated that this brain region is also sensitive to psychostimulants. Since pIIIu has been shown to respond to stress, we investigated how psychostimulant-induced pIIIu activation compares to stress- and ethanol-induced activation, and whether it is independent from a generalized stress response. Several experiments were performed to test how the pIIIu responds to psychostimulants by quantifying the number of Fos immunoreactive nuclei after acute i.p. injections of saline, 10-30 mg/kg cocaine, 5 mg/kg methamphetamine, 5 mg/kg amphetamine, 2.5 g/kg ethanol, 2 h of restraint stress, 10 min of swim stress, or six applications of mild foot shock in male C57BL/6 J mice. We also compared Fos immunoreactivity in pIIIu after acute (20 mg/kg cocaine) and repeated cocaine exposure (7 days of 20 mg/kg cocaine) injections in male C57BL/6 J mice in order to investigate the potential habituation of this response. Finally, we quantified the number of Fos immunoreactive nuclei in pIIIu after administration of saline, 2.5 g/kg ethanol, 20 mg/kg cocaine, or 2 h of restraint stress in male Sprague-Dawley rats. We found that exposure to psychostimulants and ethanol induced significantly higher Fos levels in pIIIu compared to stress in mice. Furthermore, repeated cocaine injections did not decrease Fos immunoreactivity as would be expected if this response were due to stress. In rats, exposure to ethanol, psychostimulant and restraint stress all induced pIIIu Fos immunoreactivity compared to saline-injected controls. In both mice and rats, ethanol- and cocaine-induced Fos immunoreactivity occurred exclusively in urocortin 1-positive, but not in tyrosine hydroxylase-positive, cells. These results provide evidence that the pIIIu Fos-response to psychostimulants is independent of a generalized stress in mice, but not rats. They additionally show that the pIIIu response to stress differs significantly between species.
Collapse
|