1
|
Piras G, Cadoni C, Caria F, Pintori N, Spano E, Vanejevs M, Ture A, Tocco G, Simola N, De Luca MA. Characterization of the Neurochemical and Behavioral Effects of the Phenethylamine 2-Cl-4,5-MDMA in Adolescent and Adult Male Rats. Int J Neuropsychopharmacol 2024; 27:pyae016. [PMID: 38546531 PMCID: PMC11120233 DOI: 10.1093/ijnp/pyae016] [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: 08/13/2023] [Accepted: 03/26/2024] [Indexed: 05/25/2024] Open
Abstract
BACKGROUND The proliferation of novel psychoactive substances (NPS) in the drug market raises concerns about uncertainty on their pharmacological profile and the health hazard linked to their use. Within the category of synthetic stimulant NPS, the phenethylamine 2-Cl-4,5-methylenedioxymethamphetamine (2-Cl-4,5-MDMA) has been linked to severe intoxication requiring hospitalization. Thereby, the characterization of its pharmacological profile is urgently warranted. METHODS By in vivo brain microdialysis in adolescent and adult male rats we investigated the effects of 2-Cl-4,5-MDMA on dopamine (DA) and serotonin (5-HT) neurotransmission in two brain areas critical for the motivational and rewarding properties of drugs, the nucleus accumbens (NAc) shell and the medial prefrontal cortex (mPFC). Moreover, we evaluated the locomotor and stereotyped activity induced by 2-Cl-4,5-MDMA and the emission of 50-kHz ultrasonic vocalizations (USVs) to characterize its affective properties. RESULTS 2-Cl-4,5-MDMA increased dialysate DA and 5-HT in a dose-, brain area-, and age-dependent manner. Notably, 2-Cl-4,5-MDMA more markedly increased dialysate DA in the NAc shell and mPFC of adult than adolescent rats, while the opposite was observed on dialysate 5-HT in the NAc shell, with adolescent rats being more responsive. Furthermore, 2-Cl-4,5-MDMA stimulated locomotion and stereotyped activity in both adolescent and adult rats, although to a greater extent in adolescents. Finally, 2-Cl-4,5-MDMA did not stimulate the emission of 50-kHz USVs. CONCLUSIONS This is the first pharmacological characterization of 2-Cl-4,5-MDMA demonstrating that its neurochemical and behavioral effects may differ between adolescence and adulthood. These preclinical data could help understanding the central effects of 2-Cl-4,5-MDMA by increasing awareness on possible health damage in users.
Collapse
Affiliation(s)
- Gessica Piras
- Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy
| | - Cristina Cadoni
- Institute of Neuroscience, National Research Council of Italy, Cagliari, Italy
| | - Francesca Caria
- Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy
| | - Nicholas Pintori
- Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy
| | - Enrica Spano
- Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy
| | | | | | - Graziella Tocco
- Department of Life and Environmental Sciences, University of Cagliari, Cagliari, Italy
| | - Nicola Simola
- Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy
| | | |
Collapse
|
2
|
Dusa D, Ollmann T, Kállai V, Lénárd L, Kertes E, Berta B, Szabó Á, László K, Gálosi R, Zagoracz O, Karádi Z, Péczely L. The antipsychotic drug sulpiride in the ventral pallidum paradoxically impairs learning and induces place preference. Sci Rep 2022; 12:19247. [PMID: 36357539 PMCID: PMC9649625 DOI: 10.1038/s41598-022-23450-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Accepted: 10/31/2022] [Indexed: 11/12/2022] Open
Abstract
Sulpiride, as a D2-like dopamine (DA) receptor (D2R) antagonist, is an important antipsychotic drug in the treatment of schizophrenia. Recently, we have shown that the activation of D2Rs in the ventral pallidum (VP) modulates the activity of the ventral tegmental area (VTA) DAergic neurons. According to our hypothesis, intra-VP sulpiride can influence the motivational and learning processes, pervasively modifying the behavior of examined animals. In the present study, sulpiride was microinjected into the VP of male Wistar rats in three different doses. Morris water maze (MWM) test was applied to investigate the effects of sulpiride on spatial learning, while conditioned place preference (CPP) test was used to examine the potential rewarding effect of the drug. In order to show, whether the animals can associate the rewarding effect with an area which can be recognized only on its spatial location, we introduced a modified version of the CPP paradigm, the spatial CPP test. Our results show that the intra-VP sulpiride dose-dependently impairs learning processes. However, the largest dose of sulpiride induces place preference. Results of the spatial CPP paradigm demonstrate that the animals cannot associate the rewarding effect of the drug with the conditioning area based on its spatial location. In the CPP paradigm, locomotor activity decrease could be observed in the sulpiride-treated rats, likely because of a faster habituation with the conditioning environment. In summary, we can conclude that intra-VP sulpiride has a dual effect: it diminishes the hippocampus-dependent spatial learning processes, in addition, it has a dose-dependent rewarding effect.
Collapse
Affiliation(s)
- Daniella Dusa
- grid.9679.10000 0001 0663 9479Learning in Biological and Artificial Systems Research Group, Institute of Physiology, Medical School, University of Pécs, Pécs, Hungary ,grid.9679.10000 0001 0663 9479Institute of Physiology, Medical School, University of Pécs, Szigeti Str. 12, P.O. Box: 99, Pécs, 7602 Hungary ,grid.9679.10000 0001 0663 9479Centre for Neuroscience, University of Pécs, Pécs, Hungary
| | - Tamás Ollmann
- grid.9679.10000 0001 0663 9479Learning in Biological and Artificial Systems Research Group, Institute of Physiology, Medical School, University of Pécs, Pécs, Hungary ,grid.9679.10000 0001 0663 9479Neuropeptides, Cognition, Animal Models of Neuropsychiatric Disorders Research Group, Institute of Physiology, Medical School, University of Pécs, Pécs, Hungary ,grid.9679.10000 0001 0663 9479Institute of Physiology, Medical School, University of Pécs, Szigeti Str. 12, P.O. Box: 99, Pécs, 7602 Hungary ,grid.9679.10000 0001 0663 9479Centre for Neuroscience, University of Pécs, Pécs, Hungary
| | - Veronika Kállai
- grid.9679.10000 0001 0663 9479Learning in Biological and Artificial Systems Research Group, Institute of Physiology, Medical School, University of Pécs, Pécs, Hungary ,grid.9679.10000 0001 0663 9479Neuropeptides, Cognition, Animal Models of Neuropsychiatric Disorders Research Group, Institute of Physiology, Medical School, University of Pécs, Pécs, Hungary ,grid.9679.10000 0001 0663 9479Institute of Physiology, Medical School, University of Pécs, Szigeti Str. 12, P.O. Box: 99, Pécs, 7602 Hungary ,grid.9679.10000 0001 0663 9479Centre for Neuroscience, University of Pécs, Pécs, Hungary
| | - László Lénárd
- grid.9679.10000 0001 0663 9479Institute of Physiology, Medical School, University of Pécs, Szigeti Str. 12, P.O. Box: 99, Pécs, 7602 Hungary ,grid.9679.10000 0001 0663 9479Molecular Neuroendocrinology and Neurophysiology Research Group, Szentágothai Research Centre, University of Pécs, Pécs, Hungary ,grid.9679.10000 0001 0663 9479Centre for Neuroscience, University of Pécs, Pécs, Hungary
| | - Erika Kertes
- grid.9679.10000 0001 0663 9479Learning in Biological and Artificial Systems Research Group, Institute of Physiology, Medical School, University of Pécs, Pécs, Hungary ,grid.9679.10000 0001 0663 9479Neuropeptides, Cognition, Animal Models of Neuropsychiatric Disorders Research Group, Institute of Physiology, Medical School, University of Pécs, Pécs, Hungary ,grid.9679.10000 0001 0663 9479Institute of Physiology, Medical School, University of Pécs, Szigeti Str. 12, P.O. Box: 99, Pécs, 7602 Hungary ,grid.9679.10000 0001 0663 9479Centre for Neuroscience, University of Pécs, Pécs, Hungary
| | - Beáta Berta
- grid.9679.10000 0001 0663 9479Learning in Biological and Artificial Systems Research Group, Institute of Physiology, Medical School, University of Pécs, Pécs, Hungary ,grid.9679.10000 0001 0663 9479Neuropeptides, Cognition, Animal Models of Neuropsychiatric Disorders Research Group, Institute of Physiology, Medical School, University of Pécs, Pécs, Hungary ,grid.9679.10000 0001 0663 9479Institute of Physiology, Medical School, University of Pécs, Szigeti Str. 12, P.O. Box: 99, Pécs, 7602 Hungary ,grid.9679.10000 0001 0663 9479Centre for Neuroscience, University of Pécs, Pécs, Hungary
| | - Ádám Szabó
- grid.9679.10000 0001 0663 9479Learning in Biological and Artificial Systems Research Group, Institute of Physiology, Medical School, University of Pécs, Pécs, Hungary ,grid.9679.10000 0001 0663 9479Institute of Physiology, Medical School, University of Pécs, Szigeti Str. 12, P.O. Box: 99, Pécs, 7602 Hungary
| | - Kristóf László
- grid.9679.10000 0001 0663 9479Neuropeptides, Cognition, Animal Models of Neuropsychiatric Disorders Research Group, Institute of Physiology, Medical School, University of Pécs, Pécs, Hungary ,grid.9679.10000 0001 0663 9479Institute of Physiology, Medical School, University of Pécs, Szigeti Str. 12, P.O. Box: 99, Pécs, 7602 Hungary ,grid.9679.10000 0001 0663 9479Centre for Neuroscience, University of Pécs, Pécs, Hungary
| | - Rita Gálosi
- grid.9679.10000 0001 0663 9479Institute of Physiology, Medical School, University of Pécs, Szigeti Str. 12, P.O. Box: 99, Pécs, 7602 Hungary ,grid.9679.10000 0001 0663 9479Centre for Neuroscience, University of Pécs, Pécs, Hungary
| | - Olga Zagoracz
- grid.9679.10000 0001 0663 9479Neuropeptides, Cognition, Animal Models of Neuropsychiatric Disorders Research Group, Institute of Physiology, Medical School, University of Pécs, Pécs, Hungary ,grid.9679.10000 0001 0663 9479Institute of Physiology, Medical School, University of Pécs, Szigeti Str. 12, P.O. Box: 99, Pécs, 7602 Hungary ,grid.9679.10000 0001 0663 9479Centre for Neuroscience, University of Pécs, Pécs, Hungary
| | - Zoltán Karádi
- grid.9679.10000 0001 0663 9479Institute of Physiology, Medical School, University of Pécs, Szigeti Str. 12, P.O. Box: 99, Pécs, 7602 Hungary ,grid.9679.10000 0001 0663 9479Molecular Neuroendocrinology and Neurophysiology Research Group, Szentágothai Research Centre, University of Pécs, Pécs, Hungary ,grid.9679.10000 0001 0663 9479Centre for Neuroscience, University of Pécs, Pécs, Hungary
| | - László Péczely
- grid.9679.10000 0001 0663 9479Learning in Biological and Artificial Systems Research Group, Institute of Physiology, Medical School, University of Pécs, Pécs, Hungary ,grid.9679.10000 0001 0663 9479Institute of Physiology, Medical School, University of Pécs, Szigeti Str. 12, P.O. Box: 99, Pécs, 7602 Hungary ,grid.9679.10000 0001 0663 9479Centre for Neuroscience, University of Pécs, Pécs, Hungary
| |
Collapse
|
3
|
Corongiu S, Dessì C, Cadoni C. Adolescence versus adulthood: Differences in basal mesolimbic and nigrostriatal dopamine transmission and response to drugs of abuse. Addict Biol 2020; 25:e12721. [PMID: 30779271 DOI: 10.1111/adb.12721] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 12/06/2018] [Accepted: 01/08/2019] [Indexed: 12/21/2022]
Abstract
Epidemiological studies have shown that people who begin experimenting drugs of abuse during adolescence are more likely to develop substance use disorders, and the earliest is the beginning of their use, the greatest is the likelihood to become dependent. Understanding the neurobiological changes increasing adolescent vulnerability to drug use is becoming imperative. Although all neurotransmitter systems undergo relevant developmental changes, dopamine system is of particular interest, given its role in a variety of functions related to reward, motivation, and decision making. Thus, in the present study, we investigated differences in mesolimbic and nigrostriatal dopamine transmission between adolescent (5, 6, 7 weeks of age) and adult rats (10-12 weeks of age), in basal conditions and following drug challenge, by using in vivo brain microdialysis. Although no significant difference between adolescents and adults was observed in dopamine basal levels in the nucleus accumbens (NAc)shell and core, reduced DA levels were found in the dorsolateral striatum (DLS) of early and mid-adolescent rats. Adolescent rats showed greater increase of dopamine in the NAc shell following nicotine (0.4 mg/kg), THC (1.0 mg/kg), and morphine (1.0 mg/kg), in the NAc core following nicotine and morphine, and in the DLS following THC, morphine, and cocaine (10 mg/kg). These results, while adding new insight in the development and functionality of the dopamine system during different stages of adolescence, might provide a neurochemical basis for the greater vulnerability of adolescents to drugs of abuse and for the postulated gateway effect of nicotine and THC toward abuse of other illicit substances.
Collapse
Affiliation(s)
- Silvia Corongiu
- Department of Biomedical Sciences, Neuropsychopharmacology SectionUniversity of Cagliari Italy
| | - Christian Dessì
- National Research Council of ItalyInstitute of Neuroscience Italy
| | - Cristina Cadoni
- National Research Council of ItalyInstitute of Neuroscience Italy
- Centre of Excellence “Neurobiology of Dependence”University of Cagliari Italy
| |
Collapse
|
4
|
Kesby JP, Eyles DW, McGrath JJ, Scott JG. Dopamine, psychosis and schizophrenia: the widening gap between basic and clinical neuroscience. Transl Psychiatry 2018; 8:30. [PMID: 29382821 PMCID: PMC5802623 DOI: 10.1038/s41398-017-0071-9] [Citation(s) in RCA: 196] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 10/10/2017] [Accepted: 10/26/2017] [Indexed: 12/18/2022] Open
Abstract
The stagnation in drug development for schizophrenia highlights the need for better translation between basic and clinical research. Understanding the neurobiology of schizophrenia presents substantial challenges but a key feature continues to be the involvement of subcortical dopaminergic dysfunction in those with psychotic symptoms. Our contemporary knowledge regarding dopamine dysfunction has clarified where and when dopaminergic alterations may present in schizophrenia. For example, clinical studies have shown patients with schizophrenia show increased presynaptic dopamine function in the associative striatum, rather than the limbic striatum as previously presumed. Furthermore, subjects deemed at high risk of developing schizophrenia show similar presynaptic dopamine abnormalities in the associative striatum. Thus, our view of subcortical dopamine function in schizophrenia continues to evolve as we accommodate this newly acquired information. However, basic research in animal models has been slow to incorporate these clinical findings. For example, psychostimulant-induced locomotion, the commonly utilised phenotype for positive symptoms in rodents, is heavily associated with dopaminergic activation in the limbic striatum. This anatomical misalignment has brought into question how we assess positive symptoms in animal models and represents an opportunity for improved translation between basic and clinical research. The current review focuses on the role of subcortical dopamine dysfunction in psychosis and schizophrenia. We present and discuss alternative phenotypes that may provide a more translational approach to assess the neurobiology of positive symptoms in schizophrenia. Incorporation of recent clinical findings is essential if we are to develop meaningful translational animal models.
Collapse
Affiliation(s)
- JP Kesby
- 0000 0000 9320 7537grid.1003.2Queensland Brain Institute, The University of Queensland, St. Lucia, QLD Australia ,0000 0000 9320 7537grid.1003.2Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Herston, QLD Australia
| | - DW Eyles
- 0000 0000 9320 7537grid.1003.2Queensland Brain Institute, The University of Queensland, St. Lucia, QLD Australia ,0000 0004 0606 3563grid.417162.7Queensland Centre for Mental Health Research, The Park Centre for Mental Health, Wacol, QLD Australia
| | - JJ McGrath
- 0000 0000 9320 7537grid.1003.2Queensland Brain Institute, The University of Queensland, St. Lucia, QLD Australia ,0000 0004 0606 3563grid.417162.7Queensland Centre for Mental Health Research, The Park Centre for Mental Health, Wacol, QLD Australia ,0000 0001 1956 2722grid.7048.bNational Centre for Register-based Research, Aarhus University, Aarhus C, Denmark
| | - JG Scott
- 0000 0000 9320 7537grid.1003.2Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Herston, QLD Australia ,0000 0004 0606 3563grid.417162.7Queensland Centre for Mental Health Research, The Park Centre for Mental Health, Wacol, QLD Australia ,0000 0001 0688 4634grid.416100.2Metro North Mental Health, Royal Brisbane and Women’s Hospital, Herston, QLD Australia
| |
Collapse
|
5
|
Impact of Early Consumption of High-Fat Diet on the Mesolimbic Dopaminergic System. eNeuro 2017; 4:eN-NWR-0120-17. [PMID: 28580417 PMCID: PMC5454405 DOI: 10.1523/eneuro.0120-17.2017] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Revised: 05/09/2017] [Accepted: 05/10/2017] [Indexed: 02/07/2023] Open
Abstract
Increasing evidence suggest that consumption of high-fat diet (HFD) can impact the maturation of brain circuits, such as during adolescence, which could account for behavioral alterations associated with obesity. In the present study, we used behavioral sensitization to amphetamine to investigate the effect of periadolescent HFD exposure (pHFD) in rats on the functionality of the dopamine (DA) system, a central actor in food reward processing. pHFD does not affect responding to an acute injection, however, a single exposure to amphetamine is sufficient to induce locomotor sensitization in pHFD rats. This is paralleled by rapid neurobiological adaptations within the DA system. In pHFD-exposed animals, a single amphetamine exposure induces an increase in bursting activity of DA cells in the ventral tegmental area (VTA) as well as higher DA release and greater expression of (tyrosine hydroxylase, TH) in the nucleus accumbens (NAc). Post-synaptically, pHFD animals display an increase in NAc D2 receptors and c-Fos expression after amphetamine injection. These findings highlight the vulnerability of DA system to the consumption of HFD during adolescence that may support deficits in reward-related processes observed in obesity.
Collapse
|
6
|
Dahoun T, Trossbach SV, Brandon NJ, Korth C, Howes OD. The impact of Disrupted-in-Schizophrenia 1 (DISC1) on the dopaminergic system: a systematic review. Transl Psychiatry 2017; 7:e1015. [PMID: 28140405 PMCID: PMC5299392 DOI: 10.1038/tp.2016.282] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 11/16/2016] [Accepted: 11/27/2016] [Indexed: 12/21/2022] Open
Abstract
Disrupted-in-Schizophrenia 1 (DISC1) is a gene known as a risk factor for mental illnesses possibly associated with dopamine impairments. DISC1 is a scaffold protein interacting with proteins involved in the dopamine system. Here we summarise the impact of DISC1 disruption on the dopamine system in animal models, considering its effects on presynaptic dopaminergic function (tyrosine hydroxylase levels, dopamine transporter levels, dopamine levels at baseline and after amphetamine administration) and postsynaptic dopaminergic function (dopamine D1 and D2 receptor levels, dopamine receptor-binding potential and locomotor activity after amphetamine administration). Our findings show that many but not all DISC1 models display (1) increased locomotion after amphetamine administration, (2) increased dopamine levels after amphetamine administration in the nucleus accumbens, and (3) inconsistent basal dopamine levels, dopamine receptor levels and binding potentials. There is also limited evidence for decreased tyrosine hydroxylase levels in the frontal cortex and increased dopamine transporter levels in the striatum but not nucleus accumbens, but these conclusions warrant further replication. The main dopaminergic findings are seen across different DISC1 models, providing convergent evidence that DISC1 has a role in regulating dopaminergic function. These results implicate dopaminergic dysregulation as a mechanism underlying the increased rate of schizophrenia seen in DISC1 variant carriers, and provide insights into how DISC1, and potentially DISC1-interacting proteins such as AKT and GSK-3, could be used as novel therapeutic targets for schizophrenia.
Collapse
Affiliation(s)
- T Dahoun
- Psychiatric Imaging Group MRC London Institute of Medical Sciences, Hammersmith Hospital, London, UK
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College, Hammersmith Hospital, London, UK
- Department of the Institute of Clinical Sciences, Psychiatric Imaging Group, MRC London Institute of Medical Sciences (LMS), Imperial College-Hammersmith Hospital Campus, London, UK
| | - S V Trossbach
- Department of Neuropathology, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - N J Brandon
- AstraZeneca Neuroscience, Innovative Medicines and Early Development Biotech Unit, R&D Boston, Waltham, MA, USA
| | - C Korth
- Department of Neuropathology, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - O D Howes
- Psychiatric Imaging Group MRC London Institute of Medical Sciences, Hammersmith Hospital, London, UK
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College, Hammersmith Hospital, London, UK
- Department of the Institute of Clinical Sciences, Psychiatric Imaging Group, MRC London Institute of Medical Sciences (LMS), Imperial College-Hammersmith Hospital Campus, London, UK
- Department of Psychosis Studies, Institute of Psychiatry, Neurology and Neuroscience (IoPPN), King's College London, London, UK
| |
Collapse
|
7
|
Enduring, Sexually Dimorphic Impact of In Utero Exposure to Elevated Levels of Glucocorticoids on Midbrain Dopaminergic Populations. Brain Sci 2016; 7:brainsci7010005. [PMID: 28042822 PMCID: PMC5297294 DOI: 10.3390/brainsci7010005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 12/14/2016] [Accepted: 12/16/2016] [Indexed: 11/17/2022] Open
Abstract
Glucocorticoid hormones (GCs) released from the fetal/maternal glands during late gestation are required for normal development of mammalian organs and tissues. Accordingly, synthetic glucocorticoids have proven to be invaluable in perinatal medicine where they are widely used to accelerate fetal lung maturation when there is risk of pre-term birth and to promote infant survival. However, clinical and pre-clinical studies have demonstrated that inappropriate exposure of the developing brain to elevated levels of GCs, either as a result of clinical over-use or after stress-induced activation of the fetal/maternal adrenal cortex, is linked with significant effects on brain structure, neurological function and behaviour in later life. In order to understand the underlying neural processes, particular interest has focused on the midbrain dopaminergic systems, which are critical regulators of normal adaptive behaviours, cognitive and sensorimotor functions. Specifically, using a rodent model of GC exposure in late gestation (approximating human brain development at late second/early third trimester), we demonstrated enduring effects on the shape and volume of the ventral tegmental area (VTA) and substantia nigra pars compacta (SNc) (origins of the mesocorticolimbic and nigrostriatal dopaminergic pathways) on the topographical organisation and size of the dopaminergic neuronal populations and astrocytes within these nuclei and on target innervation density and neurochemical markers of dopaminergic transmission (receptors, transporters, basal and amphetamine-stimulated dopamine release at striatal and prefrontal cortical sites) that impact on the adult brain. The effects of antenatal GC treatment (AGT) were both profound and sexually-dimorphic, not only in terms of quantitative change but also qualitatively, with several parameters affected in the opposite direction in males and females. Although such substantial neurobiological changes might presage marked behavioural effects, in utero GC exposure had only a modest or no effect, depending on sex, on a range of conditioned and unconditioned behaviours known to depend on midbrain dopaminergic transmission. Collectively, these findings suggest that apparent behavioural normality in certain tests, but not others, arises from AGT-induced adaptations or compensatory mechanisms within the midbrain dopaminergic systems, which preserve some, but not all functions. Furthermore, the capacities for molecular adaptations to early environmental challenge are different, even opponent, in males and females, which may account for their differential resilience or failure to perform adequately in behavioural tests. Behavioural "normality" is thus achieved by the midbrain dopaminergic network operating outside its normal limits (in a state of allostasis), rendering it at greater risk to malfunction when challenged in later life. Sex-specific neurobiological programming of midbrain dopaminergic systems may, therefore, have psychopathological relevance for the sex bias commonly found in brain disorders associated with these systems, and which have a neurodevelopmental component, including schizophrenia, ADHD (attention/deficit hyperactivity disorders), autism, depression and substance abuse.
Collapse
|
8
|
Taylor NE, Van Dort CJ, Kenny JD, Pei J, Guidera JA, Vlasov KY, Lee JT, Boyden ES, Brown EN, Solt K. Optogenetic activation of dopamine neurons in the ventral tegmental area induces reanimation from general anesthesia. Proc Natl Acad Sci U S A 2016; 113:12826-12831. [PMID: 27791160 PMCID: PMC5111696 DOI: 10.1073/pnas.1614340113] [Citation(s) in RCA: 155] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Dopamine (DA) promotes wakefulness, and DA transporter inhibitors such as dextroamphetamine and methylphenidate are effective for increasing arousal and inducing reanimation, or active emergence from general anesthesia. DA neurons in the ventral tegmental area (VTA) are involved in reward processing, motivation, emotion, reinforcement, and cognition, but their role in regulating wakefulness is less clear. The current study was performed to test the hypothesis that selective optogenetic activation of VTA DA neurons is sufficient to induce arousal from an unconscious, anesthetized state. Floxed-inverse (FLEX)-Channelrhodopsin2 (ChR2) expression was targeted to VTA DA neurons in DA transporter (DAT)-cre mice (ChR2+ group; n = 6). Optical VTA stimulation in ChR2+ mice during continuous, steady-state general anesthesia (CSSGA) with isoflurane produced behavioral and EEG evidence of arousal and restored the righting reflex in 6/6 mice. Pretreatment with the D1 receptor antagonist SCH-23390 before optical VTA stimulation inhibited the arousal responses and restoration of righting in 6/6 ChR2+ mice. In control DAT-cre mice, the VTA was targeted with a viral vector lacking the ChR2 gene (ChR2- group; n = 5). VTA optical stimulation in ChR2- mice did not restore righting or produce EEG changes during isoflurane CSSGA in 5/5 mice. These results provide compelling evidence that selective stimulation of VTA DA neurons is sufficient to induce the transition from an anesthetized, unconscious state to an awake state, suggesting critical involvement in behavioral arousal.
Collapse
Affiliation(s)
- Norman E Taylor
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA 02114
- Department of Anaesthesia, Harvard Medical School, Boston, MA 02114
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Christa J Van Dort
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA 02114
- Department of Anaesthesia, Harvard Medical School, Boston, MA 02114
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Jonathan D Kenny
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA 02114
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - JunZhu Pei
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA 02114
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Jennifer A Guidera
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA 02114
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Ksenia Y Vlasov
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA 02114
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Justin T Lee
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA 02114
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Edward S Boyden
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139
- Media Lab, Massachusetts Institute of Technology, Cambridge, MA 02139
- McGovern Institute, Massachusetts Institute of Technology, Cambridge, MA 02139
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Emery N Brown
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA 02114;
- Department of Anaesthesia, Harvard Medical School, Boston, MA 02114
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Ken Solt
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA 02114
- Department of Anaesthesia, Harvard Medical School, Boston, MA 02114
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139
| |
Collapse
|
9
|
Zhu X, Ottenheimer D, DiLeone RJ. Activity of D1/2 Receptor Expressing Neurons in the Nucleus Accumbens Regulates Running, Locomotion, and Food Intake. Front Behav Neurosci 2016; 10:66. [PMID: 27147989 PMCID: PMC4828436 DOI: 10.3389/fnbeh.2016.00066] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2016] [Accepted: 03/24/2016] [Indexed: 11/17/2022] Open
Abstract
While weight gain is clearly promoted by excessive energy intake and reduced expenditure, the underlying neural mechanisms of energy balance remain unclear. The nucleus accumbens (NAc) is one brain region that has received attention for its role in the regulation of energy balance; its D1 and D2 receptor containing neurons have distinct functions in regulating reward behavior and require further examination. The goal of the present study is to investigate how activation and inhibition of D1 and D2 neurons in the NAc influences behaviors related to energy intake and expenditure. Specific manipulation of D1 vs. D2 neurons was done in both low expenditure and high expenditure (wheel running) conditions to assess behavioral effects in these different states. Direct control of neural activity was achieved using a designer receptors exclusively activated by designer drugs (DREADD) strategy. Activation of NAc D1 neurons increased food intake, wheel running and locomotor activity. In contrast, activation of D2 neurons in the NAc reduced running and locomotion while D2 neuron inhibition had opposite effects. These results highlight the importance of considering both intake and expenditure in the analysis of D1 and D2 neuronal manipulations. Moreover, the behavioral outcomes from NAc D1 neuronal manipulations depend upon the activity state of the animals (wheel running vs. non-running). The data support and complement the hypothesis of specific NAc dopamine pathways facilitating energy expenditure and suggest a potential strategy for human weight control.
Collapse
Affiliation(s)
- Xianglong Zhu
- Department of Psychiatry, Yale University School of Medicine New Haven, CT, USA
| | - David Ottenheimer
- Department of Psychiatry, Yale University School of Medicine New Haven, CT, USA
| | - Ralph J DiLeone
- Department of Psychiatry, Yale University School of Medicine New Haven, CT, USA
| |
Collapse
|
10
|
Kai N, Nishizawa K, Tsutsui Y, Ueda S, Kobayashi K. Differential roles of dopamine D1 and D2 receptor-containing neurons of the nucleus accumbens shell in behavioral sensitization. J Neurochem 2015; 135:1232-41. [PMID: 26442961 DOI: 10.1111/jnc.13380] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 09/02/2015] [Accepted: 09/15/2015] [Indexed: 12/20/2022]
Abstract
The nucleus accumbens (Nac) mediates the reinforcing and motor stimulating properties of psychostimulants. It receives dopaminergic afferents from the ventral midbrain and is divided into two distinct subregions: shell and core. Each of these contains two subtypes of medium spiny neurons, which express either dopamine D1 (D1R) or D2 (D2R) receptors. However, functional dissociation between the two subtypes in psychostimulant response remains to be elucidated. We performed selective ablation of each subtype in the Nac shell in mice, using immunotoxin-mediated cell targeting, and examined the behavioral sensitization evoked by repeated administration of methamphetamine. The D1R cell-ablated mice exhibited delayed induction of sensitized locomotion compared to control mice, whereas the D2R cell-ablated mice showed a mildly enhanced rate of induction of sensitization. In vivo microdialysis revealed a marked blockade of the increase in extracellular dopamine in the Nac of the D1R cell-ablated animals in response to methamphetamine, indicating that the observed delay in behavioral sensitization in these mice involves an impairment in accumbal dopamine release. Our results reveal differential roles of D1R- and D2R-containing accumbal shell neurons in the development of behavioral sensitization to psychostimulants. Behavioral sensitization, enhanced motility by repetitive psychostimulant administration, is a model of drug addiction. Here, we show that the nucleus accumbens (Nac) shell neurons containing dopamine D1 receptor (D1R) or D2 receptor (D2R) play distinct roles in behavioral sensitization triggered by methamphetamine, and that D1R-containing neurons enhance the induction of behavioral sensitization at the early phase, whereas D2R-containing neurons act to suppress the rate of development of the behavior.
Collapse
Affiliation(s)
- Nobuyuki Kai
- Department of Molecular Genetics, Institute of Biomedical Sciences, Fukushima Medical University School of Medicine, Fukushima, Japan.,Department of Histology & Neurobiology, Dokkyo Medical University School of Medicine, Tochigi, Japan
| | - Kayo Nishizawa
- Department of Molecular Genetics, Institute of Biomedical Sciences, Fukushima Medical University School of Medicine, Fukushima, Japan
| | - Yuji Tsutsui
- Faculty of Symbiotic Systems Science, Fukushima University, Fukushima, Japan
| | - Shuichi Ueda
- Department of Histology & Neurobiology, Dokkyo Medical University School of Medicine, Tochigi, Japan
| | - Kazuto Kobayashi
- Department of Molecular Genetics, Institute of Biomedical Sciences, Fukushima Medical University School of Medicine, Fukushima, Japan
| |
Collapse
|
11
|
Gillies G, Virdee K, McArthur S, Dalley J. Sex-dependent diversity in ventral tegmental dopaminergic neurons and developmental programing: A molecular, cellular and behavioral analysis. Neuroscience 2014; 282:69-85. [PMID: 24943715 PMCID: PMC4245713 DOI: 10.1016/j.neuroscience.2014.05.033] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 05/12/2014] [Accepted: 05/18/2014] [Indexed: 02/02/2023]
Abstract
The knowledge that diverse populations of dopaminergic neurons within the ventral tegmental area (VTA) can be distinguished in terms of their molecular, electrophysiological and functional properties, as well as their differential projections to cortical and subcortical regions has significance for key brain functions, such as the regulation of motivation, working memory and sensorimotor control. Almost without exception, this understanding has evolved from landmark studies performed in the male sex. However, converging evidence from both clinical and pre-clinical studies illustrates that the structure and functioning of the VTA dopaminergic systems are intrinsically different in males and females. This may be driven by sex differences in the hormonal environment during adulthood ('activational' effects) and development (perinatal and/or pubertal 'organizational' effects), as well as genetic factors, especially the SRY gene on the Y chromosome in males, which is expressed in a sub-population of adult midbrain dopaminergic neurons. Stress and stress hormones, especially glucocorticoids, are important factors which interact with the VTA dopaminergic systems in order to achieve behavioral adaptation and enable the individual to cope with environmental change. Here, also, there is male/female diversity not only during adulthood, but also in early life when neurobiological programing by stress or glucocorticoid exposure differentially impacts dopaminergic developmental trajectories in male and female brains. This may have enduring consequences for individual resilience or susceptibility to pathophysiological change induced by stressors in later life, with potential translational significance for sex bias commonly found in disorders involving dysfunction of the mesocorticolimbic dopaminergic systems. These findings highlight the urgent need for a better understanding of the sexual dimorphism in the VTA if we are to improve strategies for the prevention and treatment of debilitating conditions which differentially affect men and women in their prevalence and nature, including schizophrenia, attention/deficit hyperactivity disorder, autism spectrum disorders, anxiety, depression and addiction.
Collapse
Affiliation(s)
- G.E. Gillies
- Division of Brain Sciences, Imperial College London, Hammersmith Hospital, London, UK,Corresponding author. Address: Division of Brain Sciences, Imperial College London, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK. Tel: +44-(0)-20-7594-7050.
| | - K. Virdee
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Downing Street, Cambridge CB2 3EB, UK,Department of Psychology, University of Cambridge, Downing Street, Cambridge CB2 3EB, UK
| | - S. McArthur
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Charterhouse Square, London EC1 6BQ, UK
| | - J.W. Dalley
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Downing Street, Cambridge CB2 3EB, UK,Department of Psychology, University of Cambridge, Downing Street, Cambridge CB2 3EB, UK,Department of Psychiatry, University of Cambridge, Addenbrooke’s Hospital, Hill’s Road, Cambridge CB2 2QQ, UK
| |
Collapse
|
12
|
Virdee K, McArthur S, Brischoux F, Caprioli D, Ungless MA, Robbins TW, Dalley JW, Gillies GE. Antenatal glucocorticoid treatment induces adaptations in adult midbrain dopamine neurons, which underpin sexually dimorphic behavioral resilience. Neuropsychopharmacology 2014; 39:339-50. [PMID: 23929547 PMCID: PMC3870772 DOI: 10.1038/npp.2013.196] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Revised: 07/11/2013] [Accepted: 08/01/2013] [Indexed: 01/22/2023]
Abstract
We demonstrated previously that antenatal glucocorticoid treatment (AGT, gestational days 16-19) altered the size and organization of the adult rat midbrain dopaminergic (DA) populations. Here we investigated the consequences of these AGT-induced cytoarchitectural disturbances on indices of DA function in adult rats. We show that in adulthood, enrichment of striatal DA fiber density paralleled AGT-induced increases in the numbers of midbrain DA neurons, which retained normal basal electrophysiological properties. This was co-incident with changes in (i) striatal D2-type receptor levels (increased, both sexes); (ii) D1-type receptor levels (males decreased; females increased); (iii) DA transporter levels (males increased; females decreased) in striatal regions; and (iv) amphetamine-induced mesolimbic DA release (males increased; females decreased). However, despite these profound, sexually dimorphic changes in markers of DA neurotransmission, in-utero glucocorticoid overexposure had a modest or no effect on a range of conditioned and unconditioned appetitive behaviors known to depend on mesolimbic DA activity. These findings provide empirical evidence for enduring AGT-induced adaptive mechanisms within the midbrain DA circuitry, which preserve some, but not all, functions, thereby casting further light on the vulnerability of these systems to environmental perturbations. Furthermore, they demonstrate these effects are achieved by different, often opponent, adaptive mechanisms in males and females, with translational implications for sex biases commonly found in midbrain DA-associated disorders.
Collapse
Affiliation(s)
- Kanwar Virdee
- Behavioral and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK,Department of Psychology, University of Cambridge, Cambridge, UK
| | - Simon McArthur
- Division of Brain Sciences, Imperial College London, Hammersmith Hospital, London, UK
| | - Frédéric Brischoux
- MRC Clinical Sciences Centre, Imperial College London, Hammersmith Hospital, London, UK
| | - Daniele Caprioli
- Behavioral and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK,Department of Psychology, University of Cambridge, Cambridge, UK
| | - Mark A Ungless
- MRC Clinical Sciences Centre, Imperial College London, Hammersmith Hospital, London, UK
| | - Trevor W Robbins
- Behavioral and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK,Department of Psychology, University of Cambridge, Cambridge, UK
| | - Jeffrey W Dalley
- Behavioral and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK,Department of Psychology, University of Cambridge, Cambridge, UK,Department of Psychiatry, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK
| | - Glenda E Gillies
- Division of Brain Sciences, Imperial College London, Hammersmith Hospital, London, UK,Division of Brain Sciences, Imperial College London, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK, Tel: +44 (0) 20 8383 8037, Fax: +44 (0) 20 8383 8032, E-mail:
| |
Collapse
|
13
|
Kaushal N, Seminerio MJ, Shaikh J, Medina MA, Mesangeau C, Wilson LL, McCurdy CR, Matsumoto RR. CM156, a high affinity sigma ligand, attenuates the stimulant and neurotoxic effects of methamphetamine in mice. Neuropharmacology 2011; 61:992-1000. [PMID: 21762711 DOI: 10.1016/j.neuropharm.2011.06.028] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2010] [Revised: 05/16/2011] [Accepted: 06/28/2011] [Indexed: 01/29/2023]
Abstract
Methamphetamine (METH) is a highly addictive psychostimulant drug of abuse. Low and high dose administration of METH leads to locomotor stimulation, and dopaminergic and serotonergic neurotoxicity, respectively. The behavioral stimulant and neurotoxic effects of METH can contribute to addiction and other neuropsychiatric disorders, thus necessitating the identification of potential pharmacotherapeutics against these effects produced by METH. METH binds to σ receptors at physiologically relevant concentrations. Also, σ receptors are present on and can modulate dopaminergic and serotonergic neurons. Therefore, σ receptors provide a viable target for the development of pharmacotherapeutics against the adverse effects of METH. In the present study, CM156, a σ receptor ligand with high affinity and selectivity for σ receptors over 80 other non-σ binding sites, was evaluated against METH-induced stimulant, hyperthermic, and neurotoxic effects. Pretreatment of male, Swiss Webster mice with CM156 dose dependently attenuated the locomotor stimulation, hyperthermia, striatal dopamine and serotonin depletions, and striatal dopamine and serotonin transporter reductions produced by METH, without significant effects of CM156 on its own. These results demonstrate the ability of a highly selective σ ligand to mitigate the effects of METH.
Collapse
Affiliation(s)
- Nidhi Kaushal
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, West Virginia University, Morgantown, WV 26506, USA
| | | | | | | | | | | | | | | |
Collapse
|
14
|
Gormley S, Rompré PP. Blockade of mGLUR5 receptors differentially alters amphetamine-induced enhancement of locomotor activity and of brain stimulation reward. J Psychopharmacol 2011; 25:393-401. [PMID: 20498134 DOI: 10.1177/0269881110367460] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study was aimed at determining the role of mGLUR5 glutamate receptors on amphetamine-induced enhancement of locomotion and of brain stimulation reward (BSR). The effect of different doses of the mGLUR5 antagonist, MPEP (0, 1, 3 and 9 mg/kg, i.p.), was assessed on reward induced by electrical stimulation of the lateral hypothalamus, and on the enhancement of reward by amphetamine (1 mg/kg, i.p.) in adult male Long Evans rats. The effect of a single dose of MPEP (0 and 9 mg/kg) on amphetamine-induced increase in locomotor activity was also assessed. Systemic injection of MPEP alone did not alter reward threshold and maximum rate of responding. Amphetamine produced a 25-30% decrease in reward threshold, an effect not altered by the highest dose of MPEP. At this dose, MPEP produced a weak inhibition of spontaneous locomotion and a significant attenuation of the enhanced locomotor activity induced by amphetamine. These findings show that mGLUR5 glutamate receptors are unlikely to constitute important elements of the reward-relevant pathway, and do not intervene in the enhancement effect of amphetamine. They also show, however, that these glutamate receptors play a key role in amphetamine-induced increased locomotor activity, providing additional evidence for a dissociation between the substrates that mediate these two behaviours.
Collapse
|
15
|
Cope ZA, Huggins KN, Sheppard AB, Noel DM, Roane DS, Brown RW. Neonatal quinpirole treatment enhances locomotor activation and dopamine release in the nucleus accumbens core in response to amphetamine treatment in adulthood. Synapse 2010; 64:289-300. [PMID: 19953655 DOI: 10.1002/syn.20729] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Neonatal quinpirole treatment to rats produces long-term increases in D(2) receptor sensitivity that persists throughout the animal's lifetime, a phenomenon referred to as D(2) priming. Male and female Sprague-dawley rats were administered quinpirole (1 mg kg(-1)) or saline from postnatal days (P)1-11. At P60, all animals were given an injection of quinpirole (100 microg kg(-1)), and results showed that rats neonatally treated with quinpirole demonstrated enhanced yawning in response to quinprole, verifying D(2) receptor priming because yawning is a D(2) receptor mediated event. Beginning 1-3 days later, locomotor sensitization was tested through administration of d-amphetamine (1 mg kg(-1)) or saline every other day over 14 days, and horizontal activity and turning behavior were analyzed. Findings indicated that D(2)-priming enhanced horizontal activity in response to amphetamine in females compared to males at Days 1 and 4 of locomotor sensitization testing, and D(2)-priming enhanced turning in response to amphetamine. Seven to ten days after sensitization was complete, microdialysis of the NAcc core was performed using a cumulative dosing regimen of amphetamine (0.1-3.0 mg kg(-1)). D(2)-primed rats administered amphetamine demonstrated a 500% increase in accumbal DA overflow compared to control rats administered amphetamine. Additionally, amphetamine produced a significant increase in NE overflow compared to controls, but this was unaffected by D(2) priming. These results indicate that D(2) receptor priming as is produced by neonatal quinpirole treatment robustly enhances behavioral activation and accumbal DA overflow in response to amphetamine, which may underlie increases in psychostimulant use and abuse within the psychotic population where increased D(2) receptor sensitivity is a hallmark.
Collapse
Affiliation(s)
- Zackary A Cope
- Department of Psychology, East Tennessee State University College of Pharmacy, Johnson City, Tennessee 37614, USA
| | | | | | | | | | | |
Collapse
|
16
|
Sellings LHL, McQuade LE, Clarke PBS. Characterization of dopamine-dependent rewarding and locomotor stimulant effects of intravenously-administered methylphenidate in rats. Neuroscience 2006; 141:1457-68. [PMID: 16753267 DOI: 10.1016/j.neuroscience.2006.04.040] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2005] [Revised: 04/12/2006] [Accepted: 04/20/2006] [Indexed: 11/24/2022]
Abstract
In general, psychostimulants are thought to exert rewarding and locomotor stimulating effects via increased dopamine transmission in the ventral striatum. However, little is known about the mechanisms underlying the effects of the stimulant drug methylphenidate. The present study examined the putative role of dopaminergic transmission in i.v. methylphenidate reward as measured by conditioned place preference. Rats were shown to exhibit conditioned place preference for i.v. methylphenidate (5 mg/kg, not 2 mg/kg). Administration of the dopamine receptor antagonist cis-flupenthixol (0.1-0.8 mg/kg i.p.), either during conditioning or on test day, dose-dependently attenuated the magnitude of the conditioned place preference. Finally, we examined the effects of bilateral 6-hydroxydopamine lesions of nucleus accumbens core, medial shell or anteromedial olfactory tubercle on the rewarding and locomotor stimulant effects of methylphenidate. Residual dopamine innervation, as assessed by radioligand binding to the dopamine transporter, revealed a significant association between core dopamine innervation and the locomotor stimulant effect of methylphenidate. However, neither core nor medial shell dopamine innervation was related to conditioned place preference magnitude. Instead, conditioned place preference magnitude was associated with dopamine innervation in the anteromedial olfactory tubercle. These results establish a role for dopaminergic transmission in both i.v. methylphenidate conditioned place preference and locomotor stimulation. As well, they suggest that different ventral striatal subregions mediate the rewarding (anteromedial olfactory tubercle) and locomotor stimulant (accumbens core) effects of methylphenidate.
Collapse
Affiliation(s)
- L H L Sellings
- Department of Pharmacology and Therapeutics, McGill University, 3655 Promenade Sir-William-Osler, Room 1325, Montreal, Quebec, Canada H3G 1Y6
| | | | | |
Collapse
|
17
|
Winstanley CA, Theobald DEH, Dalley JW, Robbins TW. Interactions between serotonin and dopamine in the control of impulsive choice in rats: therapeutic implications for impulse control disorders. Neuropsychopharmacology 2005; 30:669-82. [PMID: 15688093 DOI: 10.1038/sj.npp.1300610] [Citation(s) in RCA: 247] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Forebrain serotonergic lesions attenuate the ability of d-amphetamine to decrease impulsivity in a delay-discounting paradigm, potentially through interactions between the serotonin (5-HT) and dopamine (DA) systems. Nucleus accumbens (NAC) lesions increase impulsivity, but the extent to which accumbal DA is involved in regulating impulsive choice is unknown. In the current study, the effects of intra-accumbal infusions of 6-hydroxydopamine (6-OHDA) on impulsive choice were evaluated, in combination with d-amphetamine and serotonergic drugs, in order to investigate the importance of 5-HT : DA interactions in the control of impulsive behavior. Following training on a delay-discounting task, animals received intra-NAC 6-OHDA or sham surgery. Postoperatively, subjects received systemic injections of d-amphetamine (0, 0.3, 1.0, 1.5 mg/kg) and the 5-HT(1A) receptor agonist 8-OH-DPAT (0, 0.1, 0.3, 1.0 mg/kg). Intra-NAC 6-OHDA, which reduced local DA and NA levels by 70-75%, had no effect on delay-discounting, but transiently potentiated the d-amphetamine-induced decrease in impulsive choice. 8-OH-DPAT (1.0 mg/kg) increased impulsivity in sham-operated controls, an effect which was blocked by the 5-HT(1A) receptor antagonist WAY 100635. However, 8-OH-DPAT had no effect on impulsivity in 6-OHDA NAC lesioned rats. 8-OH-DPAT (0.3 mg/kg), which did not itself alter task performance, blocked the effect of d-amphetamine in sham-operated controls, while WAY 100635 augmented the effect of amphetamine in all subjects. In an additional experiment, intracerebroventricular administration of the selective serotonergic toxin 5,7-dihydroxytryptamine, which decreased forebrain 5-HT levels by 85-90%, did not block 8-OH-DPAT's ability to increase impulsive choice. These data suggest a significant role for 5-HT : DA interactions within the NAC in the control of impulsivity, and in the mechanism by which amphetamine decreases impulsive choice.
Collapse
MESH Headings
- 5,7-Dihydroxytryptamine/pharmacology
- 8-Hydroxy-2-(di-n-propylamino)tetralin/pharmacology
- Adrenergic Agents/pharmacology
- Amphetamine/pharmacology
- Animals
- Behavior, Animal/drug effects
- Behavior, Animal/physiology
- Disruptive, Impulse Control, and Conduct Disorders/drug therapy
- Disruptive, Impulse Control, and Conduct Disorders/metabolism
- Disruptive, Impulse Control, and Conduct Disorders/physiopathology
- Dopamine/metabolism
- Dose-Response Relationship, Drug
- Down-Regulation/drug effects
- Down-Regulation/physiology
- Male
- Neural Pathways/drug effects
- Neural Pathways/metabolism
- Neural Pathways/physiopathology
- Norepinephrine/metabolism
- Nucleus Accumbens/drug effects
- Nucleus Accumbens/metabolism
- Nucleus Accumbens/physiopathology
- Oxidopamine/pharmacology
- Piperazines/pharmacology
- Pyridines/pharmacology
- Rats
- Receptor, Serotonin, 5-HT1A/metabolism
- Serotonin/metabolism
- Serotonin 5-HT1 Receptor Agonists
- Serotonin Agents/pharmacology
- Serotonin Antagonists/pharmacology
- Serotonin Receptor Agonists/pharmacology
Collapse
|
18
|
Comoli E, Ribeiro-Barbosa ER, Negrão N, Goto M, Canteras NS. Functional mapping of the prosencephalic systems involved in organizing predatory behavior in rats. Neuroscience 2005; 130:1055-67. [PMID: 15653000 DOI: 10.1016/j.neuroscience.2004.10.020] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/12/2004] [Indexed: 01/31/2023]
Abstract
The study of the neural basis of predatory behavior has been largely neglected over the recent years. Using an ethologically based approach, we presently delineate the prosencephalic systems mobilized during predation by examining Fos immunoreactivity in rats performing insect hunting. These results were further compared with those obtained from animals killed after the early nocturnal surge of food ingestion. First, predatory behavior was associated with a distinct Fos up-regulation in the ventrolateral caudoputamen at intermediate rostro-caudal levels, suggesting a possible candidate to organize the stereotyped sequence of actions seen during insect hunting. Insect predation also presented conspicuous mobilization of a neural network formed by a distinct amygdalar circuit (i.e. the postpiriform-transition area, the anterior part of cortical nucleus, anterior part of basomedial nucleus, posterior part of basolateral nucleus, and medial part of central nucleus) and affiliated sites in the bed nuclei of the stria terminalis (i.e. the rhomboid nucleus) and in the hypothalamus (i.e. the parasubthalamic nucleus). Accordingly, this network is likely to encode prey-related motivational values, such as prey's odor and taste, and to influence autonomic and motor control accompanying predatory eating. Notably, regular food intake was also associated with a relatively weak Fos up-regulation in this network. However, during regular surge of food intake, we observed a much larger mobilization in hypothalamic sites related to the homeostatic control of eating, namely, the arcuate nucleus and autonomic parts of the paraventricular nucleus. Overall, the present findings suggest potential neural systems involved in integrating prey-related motivational values and in organizing the stereotyped sequences of action seen during predation. Moreover, the comparison with regular food intake contrasts putative neural mechanisms controlling predatory related eating vs. regular food intake.
Collapse
Affiliation(s)
- E Comoli
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Avenida Lineu Prestes, 1524, CEP 05508-900 São Paulo, SP, Brazil
| | | | | | | | | |
Collapse
|
19
|
David HN, Sissaoui K, Abraini JH. Modulation of the locomotor responses induced by D1-like and D2-like dopamine receptor agonists and D-amphetamine by NMDA and non-NMDA glutamate receptor agonists and antagonists in the core of the rat nucleus accumbens. Neuropharmacology 2004; 46:179-91. [PMID: 14680757 DOI: 10.1016/j.neuropharm.2003.08.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Dopamine and glutamate interactions in the nucleus accumbens (NAcc) play a crucial role in both the development of a motor response suitable for the environment and in the mechanisms underlying the motor-activating properties of psychostimulant drugs such as amphetamine. We investigated the effects of the infusion in the NAcc of NMDA and non-NMDA receptor agonists and antagonists on the locomotor responses induced by the selective D(1)-like receptor agonist SKF 38393, the selective D(2)-like receptor agonist quinpirole, alone or in combination, and D-amphetamine. Infusion of either the NMDA receptor agonist NMDA, the NMDA receptor antagonist D-AP5, the non-NMDA receptor antagonist CNQX, or the non-NMDA receptor agonist AMPA resulted in an increase in basal motor activity. Conversely, all of these ionotropic glutamate (iGlu) receptor ligands reduced the increase in locomotor activity induced by focal infusion of D-amphetamine. Interactions with dopamine receptor activation were not so clear: (i). infusion of NMDA and D-AP5 respectively enhanced and reduced the increase in locomotor activity induced by the infusion of the D(1)-like receptor agonist of SKF 38393, while AMPA or CNQX decreased it; (ii). infusion of NMDA, D-AP5, and CNQX reduced the increase in locomotor activity induced by co-injection of SKF 38393+quinpirole--a pharmacological condition thought to activate both D(1)-like and D(2)-like presynaptic and postsynaptic receptors, while infusion of AMPA potentiated it; (iii). infusion of either NMDA, D-AP5 or CNQX, but not of AMPA, potentiated the decrease in motor activity induced by the D(2)-like receptor agonist quinpirole, a compound believed to act only at presynaptic D(2)-like receptors when injected by itself. Our results show that NMDA receptors have an agonist action with D(1)-like receptors and an antagonist action with D(2)-like receptors, while non-NMDA receptors have the opposite action. This is discussed from a anatamo-functional point of view.
Collapse
Affiliation(s)
- Hélène N David
- Université de Caen Basse-Normandie, UMR CNRS 6551, IFR 47, Centre CYCERON, BP5229, Boulevard Henri Becquerel, 14074 Caen, cedex, France
| | | | | |
Collapse
|
20
|
Isacson R, Kull B, Wahlestedt C, Salmi P. A 68930 and dihydrexidine inhibit locomotor activity and d-amphetamine-induced hyperactivity in rats: a role of inhibitory dopamine d1/5 receptors in the prefrontal cortex? Neuroscience 2004; 124:33-42. [PMID: 14960337 DOI: 10.1016/j.neuroscience.2003.11.016] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/12/2003] [Indexed: 12/13/2022]
Abstract
The behavioral and biochemical effects of the full dopamine D(1/5) receptor agonists, dihydrexidine and (1R,3S)-1-aminomethyl-5,6-dihydroxy-3-phenylisochroman HCl (A 68930), were examined in rats. Both A 68930 (0-4.6 mg kg(-1), s.c.) and dihydrexidine (0-8.0 mg kg(-1), s.c.) caused a dose-dependent suppression of locomotor activity, as assessed in an open-field. This locomotor suppression was dose-dependently antagonized by the selective dopamine D(1/5) receptor antagonist R(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine HCl (SCH 23390; 0-5.0 microg kg(-1), s.c.), but not by the selective dopamine D(2/3) receptor antagonist raclopride (0-25.0 microg kg(-1), s.c.). Furthermore, A 68930 and dihydrexidine did not cause any locomotor activity in habituated rats that displayed a very low base-line activity. Neither did A 68930 nor dihydrexidine produce any excessive stereotypies that could possibly interfere with and mask ambulatory activity. In fact, both A 68930 and dihydrexidine potently blocked hyperactivity produced by d-amphetamine (0-4.0 mg kg(-1), s.c.). Such findings traditionally would be interpreted as a sign of potential antipsychotic properties of A 68930 and dihydrexidine. Examination of neuronal activation, as indexed by the immediate early gene c-fos, showed that A 68930 and dihydrexidine caused a highly significant expression of c-fos in the medial prefrontal cortex. This c-fos expression was sensitive to treatment with SCH 23390, but not with raclopride. The effects of A 68930 and dihydrexidine on c-fos expression in caudate putamen or nucleus accumbens were less marked, or undetectable. The results indicate that stimulation of dopamine D(1/5) receptors, possibly in the medial prefrontal cortex, is associated with inhibitory actions on locomotor activity and d-amphetamine-induced hyperactivity. Assuming an important role of prefrontal dopamine D(1/5) receptors in schizophrenia, such inhibitory actions of dopamine D(1/5) receptor stimulation on psychomotor activation may have interesting clinical implications in the treatment of schizophrenia.
Collapse
Affiliation(s)
- R Isacson
- Center for Genomics and Bioinformatics, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | | | | | | |
Collapse
|
21
|
Segregation of amphetamine reward and locomotor stimulation between nucleus accumbens medial shell and core. J Neurosci 2003. [PMID: 12867514 DOI: 10.1523/jneurosci.23-15-06295.2003] [Citation(s) in RCA: 171] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Convergent evidence suggests that amphetamine (AMPH) exerts its rewarding and locomotor stimulating effects via release of dopamine in the nucleus accumbens. However, there is no consensus as to the relative contributions of core and medial shell subregions to these effects. Moreover, the literature is based primarily on intracranial administration, which cannot fully mimic the drug distribution achieved by systemic administration. In the present study, the effects of bilateral 6-hydroxydopamine lesions of the accumbens core or medial shell on rewarding and locomotor stimulating effects of systemically administered amphetamine (0.75 mg/kg, i.p.) were examined in a conditioned place preference (CPP) procedure relying solely on tactile cues (floor texture). Residual dopamine innervation was quantified by [125I]-RTI-55 binding to the dopamine transporter. When lesions were performed before the conditioning phase, AMPH-induced locomotor stimulation and CPP magnitude were positively correlated with residual dopamine transporter binding in core and medial shell, respectively. Medial shell lesions did not affect morphine CPP, arguing that a sensory or mnemonic deficit was not responsible for the lesion-induced reduction in AMPH CPP. Medial shell lesions performed between the conditioning phase and the test day reduced the expression of amphetamine CPP. These results suggest that after systemic amphetamine administration, rewarding and locomotor stimulating effects of the drug are anatomically dissociated within the nucleus accumbens: the medial shell contributes to rewarding effects, whereas the core contributes to behavioral activation.
Collapse
|
22
|
David HN, Abraini JH. Blockade of the locomotor stimulant effects of amphetamine by group I, group II, and group III metabotropic glutamate receptor ligands in the rat nucleus accumbens: possible interactions with dopamine receptors. Neuropharmacology 2003; 44:717-27. [PMID: 12681370 DOI: 10.1016/s0028-3908(03)00052-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Previous investigations have shown that mGlu receptors would be involved in the amphetamine-induced motor response. However, data are somewhat controversial across studies where methodological protocols vary. The aim of the present study was to determine the involvement of mGlu receptors in the NAcc in the locomotor-activating properties of amphetamine in rats well habituated to their experimental environment, a condition known to modulate the motor response to amphetamine. Focal infusion of the group I mGlu receptor antagonist S-4-CPG, which has no effect on basal motor activity, virtually suppressed the locomotor response to amphetamine, while infusion of the group II mGlu receptor antagonist LY 341495 or the group III mGlu receptor agonist AP4, at the minimal dose that produces locomotor activation, reduced it by approximately a half. These effects were blocked by the group I mGlu receptor agonist DHPG, the group II mGlu receptor agonist APDC, and the group III mGlu receptor antagonist MPPG, respectively. These data confirm that mGlu receptors in the NAcc contribute to the psychostimulant motor effect of amphetamine. Results are discussed from the view of recent neuropharmacological studies that have defined the effects of these mGlu receptor ligands on basal motor activity and DA receptor agonists-induced locomotor responses in rats exposed to similar experimental procedures (Eur J Neuroscience 13 (2001) 2157; Neuropharmacology 41 (2001) 454; Eur J Neuroscience 13 (2001) 869). It is suggested that the contribution of mGlu receptors to the amphetamine-induced motor response may result mainly from their functional, either direct or indirect, interactions with D1-like receptors in the NAcc.
Collapse
Affiliation(s)
- H N David
- UMR CNRS 6551, Centre CYCERON, Université de Caen Basse-Normandie, Boulevard Henri Becquerel, BP 5229, 14074 Caen cedex, France
| | | |
Collapse
|
23
|
Chau DT, Rada P, Kosloff RA, Taylor JL, Hoebel BG. Nucleus accumbens muscarinic receptors in the control of behavioral depression: antidepressant-like effects of local M1 antagonist in the Porsolt swim test. Neuroscience 2001; 104:791-8. [PMID: 11440810 DOI: 10.1016/s0306-4522(01)00133-6] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Systemically administered cholinomimetics or cholinesterase inhibitors can depress behavior in humans and animals, whereas antimuscarinic agents reverse this effect or even produce euphoria. Although these effects have been well documented, the specific brain regions that mediate them remain largely unknown. In the present experiments, muscarinic agonists and antagonists were locally injected into the nucleus accumbens of female Sprague-Dawley rats to test for their effects on behavioral depression in the Porsolt swim test and locomotor activity. Local, microinjections of the drugs in the accumbens elicited behaviors that were similar to the systemic effects reported in other studies. Injection of the non-specific agonist arecoline (40 and 80 microg) dose-dependently inhibited swimming and escape behavior. This may be mediated in part by accumbens M1 receptors because blocking these receptors with the specific antagonist pirenzepine (17.5 and 35.0 microg) did the opposite by increasing swimming. Gallamine (0.13, 0.44, and 0.88 microg), an antagonist at M2 receptors, dose-dependently decreased swimming. Two-way microdialysis suggested that this was in part due to the release of ACh by blocking M2 autoreceptors. Scopolamine, a mixed M1/M2 receptor antagonist, also released ACh but did not decrease swimming, probably because the M1 receptors were blocked; the drug (1.0 microg) increased swimming time, much like pirenzepine. With the exception of arecoline, none of the drugs significantly affected locomotor activity in a photocell cage. Arecoline (40 microg), which had decreased swimming, reduced activity. The present study suggests that muscarinic receptors in the nucleus accumbens can control immobility in the Porsolt swim test. The onset of immobility may depend on the activation of post-synaptic M1 receptors.
Collapse
Affiliation(s)
- D T Chau
- Psychology Department, Princeton University, Princeton, NJ 08544, USA
| | | | | | | | | |
Collapse
|
24
|
Boye SM, Grant RJ, Clarke PB. Disruption of dopaminergic neurotransmission in nucleus accumbens core inhibits the locomotor stimulant effects of nicotine and D-amphetamine in rats. Neuropharmacology 2001; 40:792-805. [PMID: 11369033 DOI: 10.1016/s0028-3908(01)00003-x] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The locomotor stimulant effects of nicotine and amphetamine appear to be dependent on dopamine transmission in the nucleus accumbens. The present aim was to elucidate the contributions of the accumbens core and medial shell to these effects. In the first experiment, rats received bilateral intra-accumbens infusion of the dopaminergic antagonist eticlopride (or saline) prior to saline or nicotine (0.2 mg/kg s.c.) challenge. Eticlopride inhibited basal and nicotine-induced locomotor activity more effectively when infused into the core (0.0625--0.5 microg/side) than into the medial shell (0.5--1 microg/side). In a second experiment, rats received 6-hydroxydopamine infused into the core or medial shell, and were subsequently tested with saline, nicotine (0.2 mg/kg s.c.) and D-amphetamine (0.75 mg/kg s.c.). Residual dopaminergic innervation was assessed by autoradiographic [(125)I]RTI-55 labelling of the dopamine transporter. [(125)I]RTI-55 labelling in the accumbens core was positively correlated with the locomotor stimulant effects of both nicotine and D-amphetamine. In contrast, [(125)I]RTI-55 labelling in the medial shell was associated negatively with amphetamine-induced activity. Recent evidence suggests that dopamine release in the medial shell may mediate the reinforcing effect of nicotine and D-amphetamine. In contrast, the present findings suggest that dopamine release in the core subregion contributes preferentially to the locomotor stimulant effects of nicotine and D-amphetamine.
Collapse
Affiliation(s)
- S M Boye
- Department of Pharmacology and Therapeutics, McGill University, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada H3G 1Y6.
| | | | | |
Collapse
|
25
|
David HN, Abraini JH. The group I metabotropic glutamate receptor antagonist S-4-CPG modulates the locomotor response produced by the activation of D1-like, but not D2-like, dopamine receptors in the rat nucleus accumbens. Eur J Neurosci 2001; 13:2157-64. [PMID: 11422457 DOI: 10.1046/j.0953-816x.2001.01584.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Functional interactions between dopamine (DA) and glutamate neurotransmissions in both the dorsal and the ventral striatum have been described for long time. However, there is much controversy as to whether glutamate transmission stimulates or attenuates DA release and locomotor activity. We investigated the functional interactions on locomotor activity between group I metabotropic glutamatergic receptors (mGlu receptors) and both D1-like and D2-like DA receptors in the rat nucleus accumbens. Intra-accumbens administration of the selective group I mGlu receptor antagonist S-4-CPG (0.2 or 2 microg per side), which had no effect when injected alone, prevented the increase in locomotor activity produced by the selective D1-like receptor agonist SKF 38393 (1 microg per side). Co-administration with S-4-CPG of the group I mGlu receptor agonist DHPG, but not of the group II mGlu receptor agonist APDC or the group III mGlu receptor agonist AP4, reversed the antagonistic effect of S-4-CPG on the SKF 38393-induced increase in locomotor activity. This indicates that the antagonistic effect of S-4-CPG could result from an action at the group I mGlu receptors. In contrast, administration of S-4-CPG showed no effect on the locomotor responses produced by either the selective D2-like receptor agonist LY 171555 (1 microg per side) or a mixed solution of SKF 38393 + LY 171555 (1 microg per side each). Altogether, these results confirm that glutamate transmission may control locomotor function through mGlu receptors in a DA-dependent manner, and further indicate that group I mGlu receptors would interact with D1-like receptors, but not D2-like receptors, to modulate DA transmission and locomotor activity.
Collapse
MESH Headings
- 2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine/pharmacology
- Aminobutyrates/pharmacology
- Animals
- Benzoates/pharmacology
- Dopamine/metabolism
- Dopamine Agonists/pharmacology
- Dopamine D2 Receptor Antagonists
- Drug Interactions/physiology
- Excitatory Amino Acid Agonists/pharmacology
- Excitatory Amino Acid Antagonists/pharmacology
- Glutamic Acid/metabolism
- Glycine/analogs & derivatives
- Glycine/pharmacology
- Male
- Motor Activity/drug effects
- Motor Activity/physiology
- Neurons/drug effects
- Neurons/metabolism
- Nucleus Accumbens/cytology
- Nucleus Accumbens/drug effects
- Nucleus Accumbens/metabolism
- Proline/analogs & derivatives
- Proline/pharmacology
- Quinolines/pharmacology
- Rats
- Rats, Sprague-Dawley
- Receptors, Dopamine D1/agonists
- Receptors, Dopamine D1/antagonists & inhibitors
- Receptors, Dopamine D1/metabolism
- Receptors, Dopamine D2/agonists
- Receptors, Dopamine D2/metabolism
- Receptors, Metabotropic Glutamate/agonists
- Receptors, Metabotropic Glutamate/antagonists & inhibitors
- Receptors, Metabotropic Glutamate/metabolism
- Synaptic Transmission/drug effects
- Synaptic Transmission/physiology
Collapse
Affiliation(s)
- H N David
- UMR CNRS 6551, Centre Cyceron, BP 5229, Université de Caen, Boulevard H. Becquerel, 14074 Caen cedex, France
| | | |
Collapse
|
26
|
Gong W, Neill DB, Lynn M, Justice JB. Dopamine D1/D2 agonists injected into nucleus accumbens and ventral pallidum differentially affect locomotor activity depending on site. Neuroscience 2001; 93:1349-58. [PMID: 10501459 DOI: 10.1016/s0306-4522(99)00235-3] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Ventral pallidal dopamine has been recently shown to play an important role in psychostimulant reward and locomotor activation. The aim of the present study was to compare the roles of ventral pallidal D1 and D2 receptors in evoking locomotor activity with those in the nucleus accumbens. The D1 agonist SKF 38393 and the D2 agonist quinpirole hydrochloride (0.3-3 microg/ 0.5 microl) were bilaterally injected into ventral pallidum or nucleus accumbens through pre-implanted cannulae. In the ventral pallidum, 0.3-1 microg SKF 38393 increased locomotor activity while 3 microg had no effect; 3 microg quinpirole suppressed locomotion while 0.3-1 microg had no effect. Locomotor activity induced by an equigram (0.3 microg) mixture of SKF 38393 and quinpirole, while significantly higher than that induced by 0.3 microg quinpirole was not significantly higher than that induced by 0.3 microg SKF 38393 alone. At the 3 microg dose, SKF 38393 injections into anterior ventral pallidum increased activity; injections into posterior ventral pallidum decreased activity. In the nucleus accumbens, 0.3-3 microg SKF 38393 dramatically increased locomotor activity while quinpirole moderately increased locomotion. In the group that had previously received the full quinpirole dose range, injection of the equigram (0.3 microg) mixture of SKF 38393 and quinpirole induced locomotor activation which was higher than that induced by either drug alone or by the addition of the effect of each drug alone, i.e. synergy occurred. Moreover, rats that had previously received SKF 38393 developed a sensitized locomotor response to subsequent SKF 38393, quinpirole or the mixture of these two drugs. The difference in locomotor response to dopamine agonists between the ventral pallidum and nucleus accumbens is consistent with electrophysiological evidence collected at these two sites. These findings suggest that, unlike the nucleus accumbens, where D1 and D2 receptor activation may facilitate each other to induce a synergistic effect on locomotor activity, ventral pallidal D1 and D2 receptors may be located on different neurons and coupled with different, if not opposite, behavioral output.
Collapse
MESH Headings
- 2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine/pharmacology
- Animals
- Behavior, Animal/drug effects
- Dopamine Agonists/pharmacology
- Electrophysiology
- Globus Pallidus/chemistry
- Globus Pallidus/drug effects
- Locomotion/drug effects
- Male
- Microinjections
- Motor Activity/drug effects
- Nucleus Accumbens/chemistry
- Nucleus Accumbens/drug effects
- Quinpirole/pharmacology
- Rats
- Rats, Sprague-Dawley
- Receptors, Dopamine D1/agonists
- Receptors, Dopamine D1/physiology
- Receptors, Dopamine D2/agonists
- Receptors, Dopamine D2/physiology
Collapse
Affiliation(s)
- W Gong
- Department of Chemistry, Emory University, Atlanta, GA 30322, USA
| | | | | | | |
Collapse
|
27
|
Zhang K, Tarazi FI, Campbell A, Baldessarini RJ. GABA(B) receptors: altered coupling to G-proteins in rats sensitized to amphetamine. Neuroscience 2001; 101:5-10. [PMID: 11068131 DOI: 10.1016/s0306-4522(00)00344-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Modified dopamine and glutamate neurotransmission in discrete brain regions is implicated in stimulant-induced behavioral sensitization. Release of both neurotransmitters is influenced by GABA(B) metabotropic receptors for the principal inhibitory neurotransmitter GABA. Accordingly, GABA(B) receptors were examined in rats sensitized to amphetamine by measuring receptor density and coupling to G-proteins indicated as [(3)H]baclofen binding and baclofen-mediated [(35)S]GTP gamma S binding. Repeated treatment with (+)-amphetamine (5mg/kg per day, i.p., for five days) sensitized the rats to amphetamine challenge (1mg/kg) at 14 days, but not one day, later. GABA(B) receptor density was not altered at either time. Baclofen-mediated [(35)S]GTP gamma S binding, however, was selectively augmented in the prefrontal cortex and attenuated in the nucleus accumbens at 14 days, but not one day, after amphetamine treatment. Changes in GABA(B) receptor coupling to G-proteins in rats sensitized to amphetamine, but not in similarly treated but unsensitized rats, lead us to suggest that altered GABA(B) receptor functioning may contribute to the expression of amphetamine-induced behavioral sensitization.
Collapse
Affiliation(s)
- K Zhang
- Mailman Research Center, McLean Division of Massachusetts General Hospital, 115 Mill Street, Belmont, MA 02478, USA.
| | | | | | | |
Collapse
|
28
|
Zhang K, Tarazi FI, Baldessarini RJ. Dopamine D(4) receptors in rat forebrain: unchanged with amphetamine-induced behavioral sensitization. Neuroscience 2000; 97:211-3. [PMID: 10799752 DOI: 10.1016/s0306-4522(00)00082-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Dopamine D(2) receptors are implicated in stimulant-induced behavioral sensitization.(7,10) Studies using selective receptor antagonists also implicate the D(4) receptor, a member of the dopamine D(2)-like receptor family.(3) Accordingly, dopamine D(4) and D(2)-like receptor levels in rat forebrain were examined by computed autoradiography after repeated (+)-amphetamine treatment that induced behavioral sensitization. Receptor binding was quantified in critical brain regions including caudate-putamen, nucleus accumbens septi, medial prefrontal cortex and hippocampus. No significant differences in D(4) or D(2)-like receptor levels were detected among rats sensitized to amphetamine, those exposed to amphetamine but killed before behavioral sensitization emerged or vehicle-treated controls. The findings indicate that expression of amphetamine-induced behavioral sensitization is not associated with altered D(4) (or D(2)) receptor density in rat forebrain.
Collapse
Affiliation(s)
- K Zhang
- Mailman Research Center, McLean Division of Massachusetts General Hospital, Belmont, MA 02478, USA.
| | | | | |
Collapse
|
29
|
Frohlich J, Ogawa S, Morgan M, Burton L, Pfaff D. Hormones, genes and the structure of sexual arousal. Behav Brain Res 1999; 105:5-27. [PMID: 10553687 DOI: 10.1016/s0166-4328(99)00079-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Despite the inherent difficulty of connecting individual genes with integrated mammalian behaviors, it has been determined that a series of genes are turned on by estrogenic hormones acting in forebrain. Their products are, in turn, facilitatory for female reproductive behaviors such as lordosis. The causal routes by which two genes contribute to the control of lordosis behavior, the classical estrogen receptor gene (ER-alpha) and a thyroid hormone (TH) receptor gene (TR-beta), have been delineated. Beyond the mechanisms underlying the expression of concrete, specific natural behaviors, lies the question of sexual motivation. Required as an intervening variable to explain fluctuations in natural behaviors in the face of constant stimuli, motivational states have both general and specific features. Most theoretical and experimental approaches toward the general aspects of motivation have depended heavily on concepts of 'arousal.' Sexual arousal is likely to depend both on very general, broadly distributed neuronal influences and on specific affiliative and sexual tendencies. Is 'general arousal' a monolithic, undifferentiated process? In no way can a review at this time settle such issues, but the reasons behind six new experimental approaches to these questions are described.
Collapse
Affiliation(s)
- J Frohlich
- Laboratory of Neurobiology and Behavior, The Rockefeller University, New York, NY 10021, USA.
| | | | | | | | | |
Collapse
|
30
|
Mendlin A, Martín FJ, Jacobs BL. Dopaminergic input is required for increases in serotonin output produced by behavioral activation: an in vivo microdialysis study in rat forebrain. Neuroscience 1999; 93:897-905. [PMID: 10473255 DOI: 10.1016/s0306-4522(99)00213-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Previous research has demonstrated that pharmacological stimulation of postsynaptic dopamine D2 receptors produces increases in serotonin output. The present study explored whether this relationship also holds under physiological conditions. Accordingly, we examined the effects of D2 receptor blockade or unilateral dopamine depletion on behaviorally induced increases in extracellular serotonin levels in the corpus striatum and prefrontal cortex of freely moving rats using in vivo microdialysis. Extracellular levels of dopamine and serotonin, as well as behavioral activity, were increased by both mild tail pinch and the light-dark transition. Tail pinch-induced increases in serotonin levels (39+/-3% and 53+/-5% in the corpus striatum and prefrontal cortex, respectively), but not the accompanying behavioral changes, were blocked by local application of the D2 receptor antagonist raclopride (10 microM). D2 receptor blockade also disrupted the positive relationship between striatal serotonin levels and behavioral activity of animals across the light-dark transition (r=0.93 without raclopride, r=0.24 in presence of raclopride). Unilateral 6-hydroxydopamine lesion of the nigrostriatal dopaminergic system also abolished increases in striatal serotonin output induced by both tail pinch and light-dark transition. A negative correlation was observed between the degree of striatal dopamine depletion and tail pinch-induced increases in serotonin efflux (r= - 0.88). Thus, both a local blockade of postsynaptic D2 receptors and striatal dopamine depletion prevented increases in serotonin output that normally accompany behavioral activation. These data indicate that the increases in the forebrain serotonin output produced by two distinct physiological/environmental manipulations appear to be largely dependent upon intact local dopaminergic neurotransmission.
Collapse
Affiliation(s)
- A Mendlin
- Program in Neuroscience, Princeton University, NJ 08544-1010, USA
| | | | | |
Collapse
|
31
|
West CH, Boss-Williams KA, Weiss JM. Motor activation by amphetamine infusion into nucleus accumbens core and shell subregions of rats differentially sensitive to dopaminergic drugs. Behav Brain Res 1999; 98:155-65. [PMID: 10210531 DOI: 10.1016/s0166-4328(98)00064-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Selective breeding based on activity in a swim test has been used to produce lines of rats that show a high level of activity in the swim test (Swim High-active (SwHi) rats) and a low level of activity in the swim test (Swim Low-active (SwLo) rats). Previous studies have indicated that dopamine (DA) function is enhanced in SwHi rats and reduced in SwLo rats; a principal finding was that SwLo rats showed much smaller increases in ambulatory activity after systemic administration of amphetamine than did SwHi or non-selected rats. In light of the importance of the nucleus accumbens (NAC) in amphetamine-induced activity, the present study investigated whether DA function in NAC differs in SwHi and SwLo rats. Amphetamine was infused bilaterally into either the core or shell subregion of NAC, and ambulation or swim test activity was then measured. In SwLo rats, infusion of amphetamine (0.2-2.0 microg) into either NAC core or shell produced moderate increases in ambulation. In SwHi rats, infusion of amphetamine into NAC shell produced similar moderate increases in ambulation, but infusion into the core produced markedly larger dose-related increases in ambulation. In the swim test, infusion of amphetamine (1.0 microg) increased activity by affecting the dominant behavior of each line; i.e. struggling increased in SwHi rats and floating decreased in SwLo rats, with large effects seen in both lines with infusion into either NAC core or shell. These results support the idea that the distinct behavioral characteristics of SwHi and SwLo rats are mediated in part by differences in NAC-DA function.
Collapse
Affiliation(s)
- C H West
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA 30322, USA.
| | | | | |
Collapse
|
32
|
Louis M, Clarke PB. Effect of ventral tegmental 6-hydroxydopamine lesions on the locomotor stimulant action of nicotine in rats. Neuropharmacology 1998; 37:1503-13. [PMID: 9886673 DOI: 10.1016/s0028-3908(98)00151-8] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Convergent evidence suggests that the locomotor stimulant effect of nicotine is mediated by nicotinic receptors located on mesolimbic dopaminergic neurons. However, 6-hydroxydopamine lesions of the ventral tegmental area, resulting in substantial depletion of nucleus accumbens dopamine, were recently reported to have no effect on nicotine-induced locomotion. The present study sought to re-examine this issue. Rats received bilateral infusions of 6-hydroxydopamine or vehicle into the ventral tegmental area. Starting 3 weeks later, locomotor activity was tested after subcutaneous injection of saline, nicotine (0.4 mg/kg base), amphetamine (0.5 mg/kg) or scopolamine (0.5 mg/kg). In lesioned animals, the locomotor stimulant effects of nicotine and amphetamine were greatly reduced, whereas saline and scopolamine-induced activity was scarcely affected. Dopamine denervation was assessed by autoradiography, using [125I]RTI-55 to label plasmalemmal dopamine transporters. Labelling was reduced in nucleus accumbens core and shell and in the ventral tegmental area (by 87, 81 and 70%, respectively), and in nigrostriatal areas (52-77%). The locomotor stimulant effects of nicotine and amphetamine were correlated with residual [125I]RTI-55 labelling in mesolimbic and nigrostriatal regions (r=0.6-0.8). The present results provide further evidence that the locomotor stimulant effect of nicotine is dependent on the integrity of ascending dopamine neurons.
Collapse
Affiliation(s)
- M Louis
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
| | | |
Collapse
|
33
|
Yeghiayan SK, Gongwer MA, Baldessarini RJ, Kula NS, Zong R, Neumeyer JL. Local injection of alkylating and nonalkylating dopamine receptor antagonists into rat basal forebrain: autoradiographic assessment of D2-like and D3 sites. Brain Res 1998; 792:324-6. [PMID: 9593972 DOI: 10.1016/s0006-8993(98)00202-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
N-chloroethyl derivatives of 7-hydroxy-1,2,3,4-tetrahydronaphthalene (7-OH-DPAT), 1-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ), or fluphenazine were microinjected into rat nucleus accumbens (Acc), and receptor binding quantified autoradiographically after 24 h. EEDQ reduced [3H]nemonapride (D2-like receptors) binding in Acc (by 84%) and islands of Calleja (IC; 44%), without affecting [3H](+)-7-OH-DPAT (D3); N-chloroethyl-7-OH-DPATs blocked both radioligands in Acc and IC (30%-70%); fluphenazine had no effect.
Collapse
Affiliation(s)
- S K Yeghiayan
- Consolidated Department of Psychiatry and Neuroscience Program, Harvard Medical School, Boston, MA, USA.
| | | | | | | | | | | |
Collapse
|