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Rezaei M, Ghafouri S, Asgari A, Barkley V, Fathollahi Y, Rostami S, Shojaei A, Mirnajafi‐Zadeh J. Involvement of dopamine D 2 -like receptors in the antiepileptogenic effects of deep brain stimulation during kindling in rats. CNS Neurosci Ther 2022; 29:587-596. [PMID: 36514209 PMCID: PMC9873507 DOI: 10.1111/cns.14059] [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: 03/25/2022] [Revised: 07/25/2022] [Accepted: 11/30/2022] [Indexed: 12/15/2022] Open
Abstract
AIMS Deep brain electrical stimulation (DBS), as a potential therapy for drug resistive epileptic patients, has inhibitory action on epileptogenesis. In the present investigation, the role of dopamine D2 -like receptors in the antiepileptogenic action of DBS was studied. METHODS Seizures were induced in adult rats by stimulating the perforant path in a semi-rapid kindling method. Five minutes after the last kindling stimulation, daily DBS was applied to the perforant path at the pattern of low frequency stimulation (LFS; 1 Hz; pulse duration: 0.1 ms; intensity: 50-150 μA; 4 trains of 200 pulses at 5 min intervals). Sulpiride (10 μg/1 μl, i.c.v.), a selective dopamine D2 -like receptor antagonist, was administered prior to the daily LFS application. RESULTS Kindling stimulations increased cumulative daily behavioral seizure stages, daily afterdischarge duration (dADD), and population spike amplitude (PS) in dentate gyrus following perforant path stimulation, while applying LFS decreased the kindled seizures' parameters. In addition, kindling potentiated the early (at 10-50 ms inter-pulse interval) and late (at 150-1000 ms inter-pulse interval) paired-pulse inhibition and decreased the paired-pulse facilitation (at 70-100 ms inter-pulse interval). These effects were also inhibited by applying LFS. All inhibitory effects of LFS on kindling procedure were prevented by sulpiride administration. CONCLUSION These data may suggest that LFS exerts its preventive effect on kindling development, at least partly, through the receptors on which sulpiride acts which are mainly dopamine D2 -like (including D2 , D3 , and D4 ) receptors.
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Affiliation(s)
- Mahmoud Rezaei
- Department of Physiology, Faculty of Medical SciencesTarbiat Modares UniversityTehranIran
| | - Samireh Ghafouri
- Department of Physiology, Faculty of Medical SciencesTarbiat Modares UniversityTehranIran
| | - Azam Asgari
- Department of BiologyUniversity of VictoriaVictoriaBritish ColumbiaCanada
| | - Victoria Barkley
- Krembil Research InstituteUniversity Health NetworkTorontoOntarioCanada
| | - Yaghoub Fathollahi
- Department of Physiology, Faculty of Medical SciencesTarbiat Modares UniversityTehranIran
| | - Sareh Rostami
- Department of Physiology, Faculty of Medical SciencesTarbiat Modares UniversityTehranIran
| | - Amir Shojaei
- Department of Physiology, Faculty of Medical SciencesTarbiat Modares UniversityTehranIran
| | - Javad Mirnajafi‐Zadeh
- Department of Physiology, Faculty of Medical SciencesTarbiat Modares UniversityTehranIran,Institute for Brain Sciences and CognitionTarbiat Modares UniversityTehranIran
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2
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Trindade-Filho EM, Pai JD, Castro DND, Silva ATMD, Costa AF, Vieira JSS, Santos SDBD, Félix VB, Leão SABF, Zambrano LI, Saldanha-Filho AJM, Carvalho EGA, Cavalcante JBN, Quintella GB, Lino ATS, Costa MV, Lima JA, Tavares MMA, de Melo MR, Mousinho KC, Biase CLCLD, Leite ML, Costa PJMS, Becker EL, Moura IMFB, Silva JCD. Dopamine depletion in wistar rats with epilepsy. BRAZ J BIOL 2022; 84:e248411. [PMID: 35544785 DOI: 10.1590/1519-6984.248411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 02/20/2022] [Indexed: 11/22/2022] Open
Abstract
The dopamine content in cerebral structures has been related to neuronal excitability and several approaches have been used to study this phenomenon during seizure vulnerability period. In the present work, we describe the effects of dopamine depletion after the administration of 6-hidroxidopamine (6-OHDA) into the substantia nigra pars compacta of male rats submitted to the pilocarpine model of epilepsy. Susceptibility to pilocarpine-induced status epilepticus (SE), as well as spontaneous and recurrent seizures (SRSs) frequency during the chronic period of the model were determined. Since the hippocampus is one of main structures in the development of this experimental model of epilepsy, the dopamine levels in this region were also determined after drug administration. In the first experiment, 62% (15/24) of 6-OHDA pre-treated rats and 45% (11/24) of those receiving ascorbic acid as control solution progressed to motor limbic seizures evolving to SE, after the administration of pilocarpine. Severeness of seizures during the model´s the acute period, was significantly higher in epileptic experimental rats (56.52%), than in controls (4.16%). In the second experiment, the frequency of seizures in the model's chronic phase did not significantly change between groups. Our data show that dopamine may play an important role on seizure severity in the pilo's model acute period, which seems to be due to dopamine inhibitory action on motor expression of seizure.
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Affiliation(s)
- E M Trindade-Filho
- Centro Universitário - CESMAC, Campus I, Maceió, AL, Brasil.,Universidade Estadual de Ciências da Saúde de Alagoas - UNCISAL, Maceió, AL, Brasil
| | - J Dal Pai
- Instituto do Cérebro do Rio Grande do Sul - InsCer, Porto Alegre, RS, Brasil
| | - D N de Castro
- Centro Universitário - CESMAC, Campus I, Maceió, AL, Brasil
| | - A T M da Silva
- Centro Universitário - CESMAC, Campus I, Maceió, AL, Brasil
| | - A F Costa
- Centro Universitário - CESMAC, Campus I, Maceió, AL, Brasil
| | - J S S Vieira
- Centro Universitário - CESMAC, Campus I, Maceió, AL, Brasil
| | | | - V B Félix
- Centro Universitário - CESMAC, Campus I, Maceió, AL, Brasil.,Hospital Universitário de Alagoas Professor Alberto Antunes - HUPAA, Maceió, AL, Brasil
| | - S A B F Leão
- Santa Casa de Misericórdia de Maceió, AL, Brasil.,Universidade Federal de Alagoas - UFAL, Campus de Arapiraca, AL, Brasil
| | - L I Zambrano
- Universidad Nacional Autónoma de Honduras - UNAH, Facultad de Ciencias Medicas, Tegucigalpa, Honduras
| | - A J M Saldanha-Filho
- Centro Universitário - CESMAC, Campus I, Maceió, AL, Brasil.,Centro Universitário Tiradentes - UNIT-AL, Maceió, AL, Brasil
| | - E G A Carvalho
- Centro Universitário Tiradentes - UNIT-PE, Jaboatão dos Guararapes, Pernambuco, PE, Brasil
| | - J B N Cavalcante
- Universidade Estadual de Ciências da Saúde de Alagoas - UNCISAL, Maceió, AL, Brasil
| | - G B Quintella
- Centro Universitário - CESMAC, Campus I, Maceió, AL, Brasil
| | - A T S Lino
- Universidade Federal de Alagoas - UFAL, Campus de Rio Largo, Alagoas, Brasil
| | - M V Costa
- Centro Universitário - CESMAC, Campus I, Maceió, AL, Brasil.,Universidade Estadual de Ciências da Saúde de Alagoas - UNCISAL, Maceió, AL, Brasil
| | - J A Lima
- Centro Universitário - CESMAC, Campus I, Maceió, AL, Brasil.,Universidade Estadual de Ciências da Saúde de Alagoas - UNCISAL, Maceió, AL, Brasil
| | - M M A Tavares
- Centro Universitário - CESMAC, Campus I, Maceió, AL, Brasil
| | - M R de Melo
- Centro Universitário - CESMAC, Campus I, Maceió, AL, Brasil
| | - K C Mousinho
- Centro Universitário - CESMAC, Campus I, Maceió, AL, Brasil.,Universidade Estadual de Ciências da Saúde de Alagoas - UNCISAL, Maceió, AL, Brasil
| | - C L C L De Biase
- Hospital Universitário de Alagoas Professor Alberto Antunes - HUPAA, Maceió, AL, Brasil
| | - M L Leite
- Universidade Estadual de Ciências da Saúde de Alagoas - UNCISAL, Maceió, AL, Brasil
| | - P J M S Costa
- Universidade Estadual de Ciências da Saúde de Alagoas - UNCISAL, Maceió, AL, Brasil
| | - E L Becker
- Centro Universitário - CESMAC, Campus I, Maceió, AL, Brasil
| | - I M F B Moura
- Centro Universitário - CESMAC, Campus I, Maceió, AL, Brasil
| | - J C da Silva
- Centro Universitário - CESMAC, Campus I, Maceió, AL, Brasil.,Universidade Estadual de Ciências da Saúde de Alagoas - UNCISAL, Maceió, AL, Brasil
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3
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The psychopharmacology of epilepsy. HANDBOOK OF CLINICAL NEUROLOGY 2019. [PMID: 31727213 DOI: 10.1016/b978-0-444-64012-3.00012-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/21/2023]
Abstract
Epilepsy affects 1% of the world's population and is defined as two or more unprovoked seizures. Psychiatric conditions (depression, psychosis, anxiety, and attention deficit hyperactivity disorder (ADHD)) may coexist and are linked to negative seizure outcomes and poorer quality of life. There is an increasing body of evidence to suggest a bidirectional relationship between epilepsy and psychiatric disorders, which may imply shared pathophysiologic mechanisms. Extensive research has examined neurobiologic and neuroanatomic substrates for this association revealing some interesting similarities. Psychiatric disorders in people with epilepsy often go underdiagnosed and undertreated, due to fears of exacerbating psychiatric symptoms or provoking seizures, which may cause delays in optimal management. This chapter covers psychiatric conditions in epilepsy largely focusing on depressive disorders and psychotic disorders. Anxiety and ADHD in association with epilepsy are also discussed. Epidemiology, pathophysiologic mechanisms, and pharmacotherapies used to treat epilepsy and psychiatric disorders are also covered.
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Abstract
The psychoses of epilepsy can be classified according to their temporal relationship with seizures, namely as ictal, postictal and interictal psychosis. Interictal psychosis is the most common and may resemble schizophrenia. They can be challenging to diagnose and to manage, especially given the perception that some antipsychotic drugs may exacerbate seizures, while some antiepileptic medications may worsen psychosis. The current uncertainty around their best management means that some patients may not receive appropriate care. We propose a practical stepwise approach to managing psychosis in patients with epilepsy, summarising the key clinical features. We provide a framework for diagnosis, investigation and management of psychosis in the acute and long term. We also summarise the available evidence on the risk of psychosis with current antiepileptic drugs and the risk of seizures with antipsychotic drugs.
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Affiliation(s)
| | - Jasvinder Singh
- Department of Neuropsychiatry, Newcastle upon Tyne NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Anthony Marson
- Department of Neurology, The Walton Centre for Neurology and Neurosurgery, University of Liverpool, Liverpool, UK.,The Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, Uk
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5
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Chi SH, Jeong HG, Lee S, Oh SY, Kim SH. Effects of Psychotropic Drugs on Seizure Threshold during Electroconvulsive Therapy. Psychiatry Investig 2017; 14:647-655. [PMID: 29042890 PMCID: PMC5639133 DOI: 10.4306/pi.2017.14.5.647] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 09/27/2016] [Accepted: 10/16/2016] [Indexed: 12/31/2022] Open
Abstract
OBJECTIVE To analyze the relationship between seizure threshold (ST) and psychotropic drugs in patients treated with ECT. METHODS We examined clinical data from 43 patients. ST was titrated at each treatment session. We examined associations between ST and psychotropic drugs using multivariate correlation analyses. Data are presented as initial ST, the difference in ST between the first and 10th sessions (ΔST10th), and the mean difference in ST between the first and last sessions (mean ΔSTlast). RESULTS Multivariate regression analyses showed associations between initial ST and the total chlorpromazine-equivalent dose of antipsychotics (β=0.363, p<0.05). The total fluoxetine-equivalent dose of antidepressants was associated with ΔST10th (β=0.486, p<0.01) and mean ΔSTlast (β=0.472, p<0.01). CONCLUSION Our study elucidated possible effects of psychotropic drugs on ST shifts. Larger doses of antipsychotics were associated with higher initial ST, whereas higher doses of antidepressants were associated with stronger shifts in ST.
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Affiliation(s)
- Su-Hyuk Chi
- Department of Psychiatry, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Republic of Korea
| | - Hyun-Ghang Jeong
- Department of Psychiatry, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Republic of Korea
- Korea University Research Institute of Mental Health, Seoul, Republic of Korea
| | - Suji Lee
- Department of Biomedical Science, Korea University Graduate School, Seoul, Republic of Korea
| | - So-Young Oh
- Seoul Metropolitan Enpyeong Hospital, Seoul, Republic of Korea
| | - Seung-Hyun Kim
- Department of Psychiatry, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Republic of Korea
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6
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Brodie MJ, Besag F, Ettinger AB, Mula M, Gobbi G, Comai S, Aldenkamp AP, Steinhoff BJ. Epilepsy, Antiepileptic Drugs, and Aggression: An Evidence-Based Review. Pharmacol Rev 2017; 68:563-602. [PMID: 27255267 PMCID: PMC4931873 DOI: 10.1124/pr.115.012021] [Citation(s) in RCA: 146] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Antiepileptic drugs (AEDs) have many benefits but also many side effects, including aggression, agitation, and irritability, in some patients with epilepsy. This article offers a comprehensive summary of current understanding of aggressive behaviors in patients with epilepsy, including an evidence-based review of aggression during AED treatment. Aggression is seen in a minority of people with epilepsy. It is rarely seizure related but is interictal, sometimes occurring as part of complex psychiatric and behavioral comorbidities, and it is sometimes associated with AED treatment. We review the common neurotransmitter systems and brain regions implicated in both epilepsy and aggression, including the GABA, glutamate, serotonin, dopamine, and noradrenaline systems and the hippocampus, amygdala, prefrontal cortex, anterior cingulate cortex, and temporal lobes. Few controlled clinical studies have used behavioral measures to specifically examine aggression with AEDs, and most evidence comes from adverse event reporting from clinical and observational studies. A systematic approach was used to identify relevant publications, and we present a comprehensive, evidence-based summary of available data surrounding aggression-related behaviors with each of the currently available AEDs in both adults and in children/adolescents with epilepsy. A psychiatric history and history of a propensity toward aggression/anger should routinely be sought from patients, family members, and carers; its presence does not preclude the use of any specific AEDs, but those most likely to be implicated in these behaviors should be used with caution in such cases.
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Affiliation(s)
- Martin J Brodie
- Epilepsy Unit, West Glasgow Ambulatory Care Hospital-Yorkhill, Glasgow, Scotland (M.J.B.); East London National Health Service Foundation Trust, Bedford, United Kingdom (F.B.); University College London School of Pharmacy, London, United Kingdom (F.B.); Winthrop University Hospital, Mineola, New York (A.B.E.); Epilepsy Group, Atkinson Morley Regional Neuroscience Centre, St. George's University Hospitals National Health Service Foundation Trust, London, United Kingdom (M.M.); Institute of Medical and Biomedical Sciences, St. George's, University of London, London, United Kingdom (M.M.); Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, Quebec, Canada (G.G., S.C.); McGill University Health Center, McGill University, Montreal, Quebec, Canada (G.G., S.C.); Division of Neuroscience, San Raffaele Scientific Institute and Vita-Salute University, Milan, Italy (S.C.); Epilepsy Centre Kempenhaeghe, Heeze, The Netherlands (A.P.A.); Maastricht University Medical Centre, Maastricht, The Netherlands (A.P.A.); and Kork Epilepsy Centre, Kehl-Kork, Germany (B.J.S.)
| | - Frank Besag
- Epilepsy Unit, West Glasgow Ambulatory Care Hospital-Yorkhill, Glasgow, Scotland (M.J.B.); East London National Health Service Foundation Trust, Bedford, United Kingdom (F.B.); University College London School of Pharmacy, London, United Kingdom (F.B.); Winthrop University Hospital, Mineola, New York (A.B.E.); Epilepsy Group, Atkinson Morley Regional Neuroscience Centre, St. George's University Hospitals National Health Service Foundation Trust, London, United Kingdom (M.M.); Institute of Medical and Biomedical Sciences, St. George's, University of London, London, United Kingdom (M.M.); Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, Quebec, Canada (G.G., S.C.); McGill University Health Center, McGill University, Montreal, Quebec, Canada (G.G., S.C.); Division of Neuroscience, San Raffaele Scientific Institute and Vita-Salute University, Milan, Italy (S.C.); Epilepsy Centre Kempenhaeghe, Heeze, The Netherlands (A.P.A.); Maastricht University Medical Centre, Maastricht, The Netherlands (A.P.A.); and Kork Epilepsy Centre, Kehl-Kork, Germany (B.J.S.)
| | - Alan B Ettinger
- Epilepsy Unit, West Glasgow Ambulatory Care Hospital-Yorkhill, Glasgow, Scotland (M.J.B.); East London National Health Service Foundation Trust, Bedford, United Kingdom (F.B.); University College London School of Pharmacy, London, United Kingdom (F.B.); Winthrop University Hospital, Mineola, New York (A.B.E.); Epilepsy Group, Atkinson Morley Regional Neuroscience Centre, St. George's University Hospitals National Health Service Foundation Trust, London, United Kingdom (M.M.); Institute of Medical and Biomedical Sciences, St. George's, University of London, London, United Kingdom (M.M.); Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, Quebec, Canada (G.G., S.C.); McGill University Health Center, McGill University, Montreal, Quebec, Canada (G.G., S.C.); Division of Neuroscience, San Raffaele Scientific Institute and Vita-Salute University, Milan, Italy (S.C.); Epilepsy Centre Kempenhaeghe, Heeze, The Netherlands (A.P.A.); Maastricht University Medical Centre, Maastricht, The Netherlands (A.P.A.); and Kork Epilepsy Centre, Kehl-Kork, Germany (B.J.S.)
| | - Marco Mula
- Epilepsy Unit, West Glasgow Ambulatory Care Hospital-Yorkhill, Glasgow, Scotland (M.J.B.); East London National Health Service Foundation Trust, Bedford, United Kingdom (F.B.); University College London School of Pharmacy, London, United Kingdom (F.B.); Winthrop University Hospital, Mineola, New York (A.B.E.); Epilepsy Group, Atkinson Morley Regional Neuroscience Centre, St. George's University Hospitals National Health Service Foundation Trust, London, United Kingdom (M.M.); Institute of Medical and Biomedical Sciences, St. George's, University of London, London, United Kingdom (M.M.); Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, Quebec, Canada (G.G., S.C.); McGill University Health Center, McGill University, Montreal, Quebec, Canada (G.G., S.C.); Division of Neuroscience, San Raffaele Scientific Institute and Vita-Salute University, Milan, Italy (S.C.); Epilepsy Centre Kempenhaeghe, Heeze, The Netherlands (A.P.A.); Maastricht University Medical Centre, Maastricht, The Netherlands (A.P.A.); and Kork Epilepsy Centre, Kehl-Kork, Germany (B.J.S.)
| | - Gabriella Gobbi
- Epilepsy Unit, West Glasgow Ambulatory Care Hospital-Yorkhill, Glasgow, Scotland (M.J.B.); East London National Health Service Foundation Trust, Bedford, United Kingdom (F.B.); University College London School of Pharmacy, London, United Kingdom (F.B.); Winthrop University Hospital, Mineola, New York (A.B.E.); Epilepsy Group, Atkinson Morley Regional Neuroscience Centre, St. George's University Hospitals National Health Service Foundation Trust, London, United Kingdom (M.M.); Institute of Medical and Biomedical Sciences, St. George's, University of London, London, United Kingdom (M.M.); Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, Quebec, Canada (G.G., S.C.); McGill University Health Center, McGill University, Montreal, Quebec, Canada (G.G., S.C.); Division of Neuroscience, San Raffaele Scientific Institute and Vita-Salute University, Milan, Italy (S.C.); Epilepsy Centre Kempenhaeghe, Heeze, The Netherlands (A.P.A.); Maastricht University Medical Centre, Maastricht, The Netherlands (A.P.A.); and Kork Epilepsy Centre, Kehl-Kork, Germany (B.J.S.)
| | - Stefano Comai
- Epilepsy Unit, West Glasgow Ambulatory Care Hospital-Yorkhill, Glasgow, Scotland (M.J.B.); East London National Health Service Foundation Trust, Bedford, United Kingdom (F.B.); University College London School of Pharmacy, London, United Kingdom (F.B.); Winthrop University Hospital, Mineola, New York (A.B.E.); Epilepsy Group, Atkinson Morley Regional Neuroscience Centre, St. George's University Hospitals National Health Service Foundation Trust, London, United Kingdom (M.M.); Institute of Medical and Biomedical Sciences, St. George's, University of London, London, United Kingdom (M.M.); Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, Quebec, Canada (G.G., S.C.); McGill University Health Center, McGill University, Montreal, Quebec, Canada (G.G., S.C.); Division of Neuroscience, San Raffaele Scientific Institute and Vita-Salute University, Milan, Italy (S.C.); Epilepsy Centre Kempenhaeghe, Heeze, The Netherlands (A.P.A.); Maastricht University Medical Centre, Maastricht, The Netherlands (A.P.A.); and Kork Epilepsy Centre, Kehl-Kork, Germany (B.J.S.)
| | - Albert P Aldenkamp
- Epilepsy Unit, West Glasgow Ambulatory Care Hospital-Yorkhill, Glasgow, Scotland (M.J.B.); East London National Health Service Foundation Trust, Bedford, United Kingdom (F.B.); University College London School of Pharmacy, London, United Kingdom (F.B.); Winthrop University Hospital, Mineola, New York (A.B.E.); Epilepsy Group, Atkinson Morley Regional Neuroscience Centre, St. George's University Hospitals National Health Service Foundation Trust, London, United Kingdom (M.M.); Institute of Medical and Biomedical Sciences, St. George's, University of London, London, United Kingdom (M.M.); Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, Quebec, Canada (G.G., S.C.); McGill University Health Center, McGill University, Montreal, Quebec, Canada (G.G., S.C.); Division of Neuroscience, San Raffaele Scientific Institute and Vita-Salute University, Milan, Italy (S.C.); Epilepsy Centre Kempenhaeghe, Heeze, The Netherlands (A.P.A.); Maastricht University Medical Centre, Maastricht, The Netherlands (A.P.A.); and Kork Epilepsy Centre, Kehl-Kork, Germany (B.J.S.)
| | - Bernhard J Steinhoff
- Epilepsy Unit, West Glasgow Ambulatory Care Hospital-Yorkhill, Glasgow, Scotland (M.J.B.); East London National Health Service Foundation Trust, Bedford, United Kingdom (F.B.); University College London School of Pharmacy, London, United Kingdom (F.B.); Winthrop University Hospital, Mineola, New York (A.B.E.); Epilepsy Group, Atkinson Morley Regional Neuroscience Centre, St. George's University Hospitals National Health Service Foundation Trust, London, United Kingdom (M.M.); Institute of Medical and Biomedical Sciences, St. George's, University of London, London, United Kingdom (M.M.); Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, Quebec, Canada (G.G., S.C.); McGill University Health Center, McGill University, Montreal, Quebec, Canada (G.G., S.C.); Division of Neuroscience, San Raffaele Scientific Institute and Vita-Salute University, Milan, Italy (S.C.); Epilepsy Centre Kempenhaeghe, Heeze, The Netherlands (A.P.A.); Maastricht University Medical Centre, Maastricht, The Netherlands (A.P.A.); and Kork Epilepsy Centre, Kehl-Kork, Germany (B.J.S.)
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7
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Chakroborty D, Sarkar C, Lu K, Bhat M, Dasgupta PS, Basu S. Activation of Dopamine D1 Receptors in Dermal Fibroblasts Restores Vascular Endothelial Growth Factor-A Production by These Cells and Subsequent Angiogenesis in Diabetic Cutaneous Wound Tissues. THE AMERICAN JOURNAL OF PATHOLOGY 2016; 186:2262-70. [PMID: 27422612 DOI: 10.1016/j.ajpath.2016.05.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 04/28/2016] [Accepted: 05/04/2016] [Indexed: 01/11/2023]
Abstract
In wound beds, fibroblasts are rich sources of vascular endothelial growth factor A, a cytokine necessary for promoting angiogenesis and thereby the healing of wound tissues. However, in diabetes mellitus, these cells are functionally impaired and produce reduced amounts of vascular endothelial growth factor A, resulting in deficient angiogenesis and delayed wound healing. We here for the first time demonstrate that stimulation of D1 dopamine receptors present in dermal fibroblasts restores vascular endothelial growth factor A production by these cells, resulting in adequate angiogenesis and subsequent healing of cutaneous wounds in both type 1 and type 2 diabetic mice. This action of D1 dopamine receptors was mediated through the protein kinase A pathway. As delayed wound healing or chronic wounds are one of the major health problems in diabetic patients, D1 dopamine receptor agonists, which are already in clinical use for the treatment of other disorders, may be of translational value in the treatment of chronic, nonhealing diabetic wounds.
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Affiliation(s)
| | | | - Kai Lu
- Department of Pathology, Ohio State University, Columbus, Ohio
| | - Madhavi Bhat
- Department of Pathology, Ohio State University, Columbus, Ohio
| | | | - Sujit Basu
- Department of Pathology, Ohio State University, Columbus, Ohio; Division of Medical Oncology, Department of Internal Medicine, Ohio State University, Columbus, Ohio.
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8
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Butini S, Nikolic K, Kassel S, Brückmann H, Filipic S, Agbaba D, Gemma S, Brogi S, Brindisi M, Campiani G, Stark H. Polypharmacology of dopamine receptor ligands. Prog Neurobiol 2016; 142:68-103. [PMID: 27234980 DOI: 10.1016/j.pneurobio.2016.03.011] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 01/26/2016] [Accepted: 03/15/2016] [Indexed: 01/11/2023]
Abstract
Most neurological diseases have a multifactorial nature and the number of molecular mechanisms discovered as underpinning these diseases is continuously evolving. The old concept of developing selective agents for a single target does not fit with the medical need of most neurological diseases. The development of designed multiple ligands holds great promises and appears as the next step in drug development for the treatment of these multifactorial diseases. Dopamine and its five receptor subtypes are intimately involved in numerous neurological disorders. Dopamine receptor ligands display a high degree of cross interactions with many other targets including G-protein coupled receptors, transporters, enzymes and ion channels. For brain disorders like Parkinsońs disease, schizophrenia and depression the dopaminergic system, being intertwined with many other signaling systems, plays a key role in pathogenesis and therapy. The concept of designed multiple ligands and polypharmacology, which perfectly meets the therapeutic needs for these brain disorders, is herein discussed as a general ligand-based concept while focusing on dopaminergic agents and receptor subtypes in particular.
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Affiliation(s)
- S Butini
- Department of Biotechnology, Chemistry and Pharmacy, European Research Centre for Drug Discovery and Development, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - K Nikolic
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11000 Belgrade, Serbia
| | - S Kassel
- Heinrich Heine University Duesseldorf, Institute of Pharmaceutical and Medicinal Chemistry, Universitaetsstr. 1, 40225 Duesseldorf, Germany
| | - H Brückmann
- Heinrich Heine University Duesseldorf, Institute of Pharmaceutical and Medicinal Chemistry, Universitaetsstr. 1, 40225 Duesseldorf, Germany
| | - S Filipic
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11000 Belgrade, Serbia
| | - D Agbaba
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11000 Belgrade, Serbia
| | - S Gemma
- Department of Biotechnology, Chemistry and Pharmacy, European Research Centre for Drug Discovery and Development, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - S Brogi
- Department of Biotechnology, Chemistry and Pharmacy, European Research Centre for Drug Discovery and Development, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - M Brindisi
- Department of Biotechnology, Chemistry and Pharmacy, European Research Centre for Drug Discovery and Development, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - G Campiani
- Department of Biotechnology, Chemistry and Pharmacy, European Research Centre for Drug Discovery and Development, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - H Stark
- Heinrich Heine University Duesseldorf, Institute of Pharmaceutical and Medicinal Chemistry, Universitaetsstr. 1, 40225 Duesseldorf, Germany.
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Gangarossa G, Ceolin L, Paucard A, Lerner-Natoli M, Perroy J, Fagni L, Valjent E. Repeated stimulation of dopamine D1-like receptor and hyperactivation of mTOR signaling lead to generalized seizures, altered dentate gyrus plasticity, and memory deficits. Hippocampus 2014; 24:1466-81. [DOI: 10.1002/hipo.22327] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/02/2014] [Indexed: 01/18/2023]
Affiliation(s)
- Giuseppe Gangarossa
- CNRS, UMR-5203, Institut de Génomique Fonctionnelle; Montpellier France
- INSERM, U661; Montpellier France
- Universités de Montpellier 1 & 2; UMR-5203 Montpellier France
| | - Laura Ceolin
- CNRS, UMR-5203, Institut de Génomique Fonctionnelle; Montpellier France
- INSERM, U661; Montpellier France
- Universités de Montpellier 1 & 2; UMR-5203 Montpellier France
| | - Alexia Paucard
- CNRS, UMR-5203, Institut de Génomique Fonctionnelle; Montpellier France
- INSERM, U661; Montpellier France
- Universités de Montpellier 1 & 2; UMR-5203 Montpellier France
| | - Mireille Lerner-Natoli
- CNRS, UMR-5203, Institut de Génomique Fonctionnelle; Montpellier France
- INSERM, U661; Montpellier France
- Universités de Montpellier 1 & 2; UMR-5203 Montpellier France
| | - Julie Perroy
- CNRS, UMR-5203, Institut de Génomique Fonctionnelle; Montpellier France
- INSERM, U661; Montpellier France
- Universités de Montpellier 1 & 2; UMR-5203 Montpellier France
| | - Laurent Fagni
- CNRS, UMR-5203, Institut de Génomique Fonctionnelle; Montpellier France
- INSERM, U661; Montpellier France
- Universités de Montpellier 1 & 2; UMR-5203 Montpellier France
| | - Emmanuel Valjent
- CNRS, UMR-5203, Institut de Génomique Fonctionnelle; Montpellier France
- INSERM, U661; Montpellier France
- Universités de Montpellier 1 & 2; UMR-5203 Montpellier France
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10
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The role of different serotonin receptor subtypes in seizure susceptibility. Exp Brain Res 2013; 232:347-67. [PMID: 24232860 DOI: 10.1007/s00221-013-3757-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Accepted: 10/27/2013] [Indexed: 10/26/2022]
Abstract
5-Hydroxytryptamine (5-HT) has the most diverse set of receptors in comparison with any other neurotransmitter or hormone in the body. To date, seven families of 5-HT receptors have been characterized. A great number of studies have been published regarding the role of 5-HT and its receptors in seizures. However, with a few exceptions, the net effect of activating or inhibiting each 5-HT receptor subtype on the development or severity of seizures remains controversial. Additionally, the results of studies, which have used knockout animals to investigate the role of 5-HT receptors in seizures, have sometimes been contradictory to those which have used pharmacological tools. The present study aims to review the available data regarding the influence of each receptor subtype on seizure development and, when possible, reconcile between the apparently different results obtained in these studies.
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Gangarossa G, Valjent E. Regulation of the ERK pathway in the dentate gyrus by in vivo dopamine D1 receptor stimulation requires glutamatergic transmission. Neuropharmacology 2012; 63:1107-17. [PMID: 22796106 DOI: 10.1016/j.neuropharm.2012.06.062] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2012] [Revised: 06/22/2012] [Accepted: 06/29/2012] [Indexed: 11/18/2022]
Abstract
Acute systemic administration of the dopamine D1/D5 receptors (D1Rs) agonist, SKF81297, activates the extracellular signal-regulated protein kinases (ERK) pathway selectively in the granule cells of the dentate gyrus. In this study, we examined the mechanisms involved in this regulation and investigated the molecular components that could promote ERK-dependent transcription and translation. SKF81297 induced phosphorylation of ERK and histone H3 required intact glutamatergic transmission. Blockade of glutamate release achieved by the mGluR2/3 agonist, LY354740 or the selective adenosine A1R agonist, CCPA as well as neurotoxic lesions of lateral entorhinal cortex reduced the ability of SKF81297 to induce ERK activation in the dentate gyrus. This activation required the combined stimulation of NR2B-containing NMDARs, mGluR1 and mGluR5. SKF81297 evoked phosphorylation of the ribosomal protein S6 (rpS6) selectively at the Ser235/236 site while the Ser240/244 site remains unchanged. The SKF81297 induced increased phosphorylation of rpS6 was dependent on PKC and ERK/p90RSK activation. Surprisingly, administration of D1Rs agonist suppressed mTORC1/p70S6K pathway suggesting an mTOR-independent regulation of rpS6 phosphorylation. Taken together, our results show that intact glutamatergic transmission plays a major role in the regulation of ERK-dependent phosphorylation of histone H3 and rpS6 observed in the mouse dentate gyrus after systemic administration of SKF81297.
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Sharopov S, Moser J, Chen R, Kolbaev SN, Bernedo VE, Werhahn KJ, Luhmann HJ, Kilb W. Dopaminergic modulation of low-Mg2+-induced epileptiform activity in the intact hippocampus of the newborn mouse in vitro. J Neurosci Res 2012; 90:2020-33. [DOI: 10.1002/jnr.23084] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Revised: 04/11/2012] [Accepted: 04/13/2012] [Indexed: 11/12/2022]
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13
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Mannaa F, El-Shamy KA, El-Shaikh KA, El-Kassaby M. Efficacy of fish liver oil and propolis as neuroprotective agents in pilocarpine epileptic rats treated with valproate. PATHOPHYSIOLOGY 2011; 18:287-94. [DOI: 10.1016/j.pathophys.2011.04.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2009] [Revised: 04/17/2010] [Accepted: 04/20/2011] [Indexed: 11/17/2022] Open
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14
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Calabrese EJ. Modulation of the Epileptic Seizure Threshold: Implications of Biphasic Dose Responses. Crit Rev Toxicol 2008; 38:543-56. [DOI: 10.1080/10408440802014261] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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15
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Saberi M, Rezvanizadeh A, Bakhtiarian A. The antiepileptic activity of Vitex agnus castus extract on amygdala kindled seizures in male rats. Neurosci Lett 2008; 441:193-6. [DOI: 10.1016/j.neulet.2008.06.034] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2008] [Revised: 05/31/2008] [Accepted: 06/12/2008] [Indexed: 11/27/2022]
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16
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Tchekalarova J, Sotiriou E, Angelatou F. Down-regulation of dopamine D1 and D2 receptors in the basal ganglia of PTZ kindling model of epilepsy: effects of angiotensin IV. Brain Res 2005; 1024:159-66. [PMID: 15451378 DOI: 10.1016/j.brainres.2004.07.060] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/31/2004] [Indexed: 10/26/2022]
Abstract
The present study examined the effect of pentylenetetrazol (PTZ) induced kindling as well as the action of the hexapeptide angiotensin IV (ANG IV) on the dopamine (DA) D1 and D2 receptor binding in the basal ganglia of the mouse brain. By using quantitative receptor autoradiography, it was found that PTZ kindling led to a decrease in DA D2 receptor density (about 20%) in all regions of the neostriatum (NS) as well as in the olfactory tubercle (OT), the nucleus accumbens (NA) and the globus pallidus, which persisted 24 h and 7 days after the kindling procedure. PTZ induced kindling also elicited a decrease in DA D1 receptor binding sites (about 10%), which however was, restricted to the rostral NS (rNA) and NA. ANG IV (0.2 mg/kg), injected prior to PTZ, not only prevented the development of the kindling process but it also reversed the kindling-induced down-regulation of both DA receptors to the control levels. Furthermore ANG IV induced an area-specific increase of DA D1 receptor density above control levels in the dorsal part of rNS. These findings suggest that DA D2 receptors could mainly contribute to epileptogenesis in the PTZ kindling model, whereas the role of DA D1 receptors is limited to particular regions in the basal ganglia. The anticonvulsant effect of ANG IV pretreatment might be influenced by a DA-related mechanism and particularly by preventing D2 receptor down-regulation as well as by an adaptive area-specific increase in DA D1 receptors.
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Affiliation(s)
- Jana Tchekalarova
- Laboratory of Experimental Psychopharmacology, Institute of Physiology, Acad. G. Bonchev Str., Bl. 23, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria.
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Weinshenker D, Szot P. The role of catecholamines in seizure susceptibility: new results using genetically engineered mice. Pharmacol Ther 2002; 94:213-33. [PMID: 12113799 DOI: 10.1016/s0163-7258(02)00218-8] [Citation(s) in RCA: 123] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The catecholamines norepinephrine and dopamine are abundant in the CNS, and modulate neuronal excitability via G-protein-coupled receptor signaling. This review covers the history of research concerning the role of catecholamines in modulating seizure susceptibility in animal models of epilepsy. Traditionally, most work on this topic has been anatomical, pharmacological, or physiological in nature. However, the recent advances in transgenic and knockout mouse technology provide new tools to study catecholamines and their roles in seizure susceptibility. New results from genetically engineered mice with altered catecholamine signaling, as well as possibilities for future experiments, are discussed.
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Affiliation(s)
- David Weinshenker
- Howard Hughes Medical Institute and Department of Biochemistry, University of Washington, Box 357370, Seattle, WA 98195, USA.
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Bourne JA, Fosbraey P, Halliday J. SCH 23390 affords protection against soman-evoked seizures in the freely moving guinea-pig: a concomitant neurochemical, electrophysiological and behavioural study. Neuropharmacology 2001; 40:279-88. [PMID: 11114407 DOI: 10.1016/s0028-3908(00)00136-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We studied the role of striatal dopamine (DA) release in seizure activity evoked by the subcutaneous administration of the cholinesterase inhibitor pinacolyl methylphosphonofluoridate (soman), in the guinea-pig. The involvement of the dopamine receptor subtypes was studied by systemic administration of the D(1)-like receptor antagonist SCH 23390 (0.5 mg kg(-1)) or the D(2)-like receptor antagonist sulpiride (30 mg kg(-1)). Microdialysis and HPLC with electrochemical detection were used to monitor changes in extracellular levels of striatal DA and its metabolites, acetylcholine and choline. These data were correlated with changes in the striatal and cortical electroencephalogram and observation of predefined clinical signs. We found that the blockade of the D(1) receptor with SCH 23390 can inhibit seizure activity, while blockade of the D(2) receptor with sulpiride can augment the evoked seizure activity. These results clarify the involvement of the dopaminergic system in soman-evoked seizures.
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Affiliation(s)
- J A Bourne
- Biomedical Sciences Department, CBD Porton Down, Salisbury SP4 0JQ, UK.
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Bourne JA, Fosbraey P, Halliday J. Changes in striatal electroencephalography and neurochemistry induced by kainic acid seizures are modified by dopamine receptor antagonists. Eur J Pharmacol 2001; 413:189-98. [PMID: 11226392 DOI: 10.1016/s0014-2999(01)00747-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We investigated the involvement of striatal dopamine release in electrographic and motor seizure activity evoked by kainic acid in the guinea pig. The involvement of the dopamine receptor subtypes was studied by systemic administration of the dopamine D(1) receptor antagonist, R(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine hydrochloride (SCH 23390; 0.5 mg kg(-1)), or the dopamine D(2) antagonist, (5-aminosulphonyl)-N-[(1-ethyl-2-pyrrolidinyl)-methyl]-2-methoxybenzamide (sulpiride, 30 mg kg(-1)). Microdialysis and high performance liquid chromatography were used to monitor changes in extracellular levels of striatal dopamine and its metabolites, glutamate, aspartate and gamma-amino-butyric acid (GABA). These data were correlated with changes in the striatal and cortical electroencephalographs and clinical signs. We found that, although neither dopamine receptor antagonist inhibited behavioural seizure activity, blockade of the dopamine D(1)-like receptor with SCH 23390 significantly reduced both the 'power' of the electrical seizure activity and the associated change in extracellular striatal concentration of glutamate, whilst increasing the extracellular striatal concentration of GABA. In contrast, blockade of the dopamine D(2)-like receptor with sulpiride significantly increased the extracellular, striatal content of glutamate and the dopamine metabolites. These results confirm previous evidence in other models of chemically-evoked seizures that antagonism of the dopamine D(1) receptor tends to reduce motor and electrographic seizure activity as well as excitatory amino-acid transmitter activity, while antagonism of the dopamine D(2) receptor has relatively less apparent effect.
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Affiliation(s)
- J A Bourne
- Biomedical Sciences Department, CBD Porton Down, Salisbury SP4 0JQ, UK.
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20
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Abstract
SCH 23390, the halobenzazepine (R)-(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5- tetrahydro-1H-3-benzazepine, is a highly potent and selective dopamine D1-like receptor antagonist with a K(i) of 0.2 and 0.3 nM for the D1 and D5 dopamine receptor subtypes, respectively. In vitro, it also binds with high affinity to the 5-HT2 and 5-HT1C serotonin receptor subtypes. However, the doses required to induce a similar response in vivo are greater than 10-fold higher than those required to induce a D1-mediated response. Previous in vivo pharmacological studies with SCH 23390 have shown it to abolish generalized seizures evoked by the chemoconvulsants: pilocarpine and soman. These studies provide evidence of the potential importance of D1-like dopaminergic receptor mechanisms in facilitating the initiation and spread of seizures. The inference from a majority of studies is that the activation of dopamine D1 receptors facilitates seizure activity, whereas activation of D2 receptors may inhibit the development of seizures. SCH 23390 has also been used in studies of other neurological disorders in which the dopamine system has been implicated, such as psychosis and Parkinson's disease. Apart from the study of neurological disorders, SCH 23390 has been extensively used as a tool in the topographical determination of brain D1 receptors in rodents, nonhuman primates, and humans. In summary, SCH 23390 has been a major tool in gaining a better understanding of the role of the dopamine system, more specifically the D1 receptor, in neurological function and dysfunction.
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Affiliation(s)
- J A Bourne
- Department of Physiology, Monash University, Clayton, Victoria, 3800, Australia.
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21
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Fukuda M, Niwa SI, Kumagai N, Nagakubo S, Hashimoto O, Shirayama Y, Hata A, Kameyama T, Anzai N. Plasma homovanillic acid levels in temporal lobe epilepsy. ACTA ACUST UNITED AC 1998. [DOI: 10.1016/s0896-6974(98)00031-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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22
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Marinho MM, de Sousa FC, de Bruin VM, Vale MR, Viana GS. Effects of lithium, alone or associated with pilocarpine, on muscarinic and dopaminergic receptors and on phosphoinositide metabolism in rat hippocampus and striatum. Neurochem Int 1998; 33:299-306. [PMID: 9840220 DOI: 10.1016/s0197-0186(98)00028-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The mechanism of action of lithium (Li) alone or with pilocarpine (Pilo), focusing on muscarinic and dopaminergic systems and also on phosphoinositide metabolism was studied. Li (3 mEq/kg) administered to rats once (1 d) or daily for 7 days (7 d), 24 h before Pilo (15 mg/kg), exacerbated cholinergic signs, leading to tremors. convulsions and brain lesions. Increases in muscarinic receptors (MR) of 29 and 49% were observed in the hippocampus after atropine (Atro) and Li-Atro-Pilo treatments, respectively, as compared to controls (Atro) and the Li-Pilo group (Li-Atro-Pilo). In the striatum, except for the 37% increase in the Li-Atro (50 mg/kg)-Pilo group as compared to the Li-Pilo one, no other changes were observed in MR. A decrease of 32% on average in D2-like receptors (D2R) was detected in the hippocampus in the group Li-7d. On the contrary, in the striatum an increase (25%) in the Li-7d group was observed and this effect was blocked by Li-Pilo. As far as inositol phosphates (IP) and phosphatidylinositol-4,5-biphosphate (PIP2) metabolism is concerned, Li caused a decrease (28%) and an increase (60%) in IP and PIP2 accumulations, respectively, in hippocampus slices while Pilo only altered IP accumulation (32% decrease). In this area the association of Li-Atro (10 mg/kg)-Pilo also caused a decrease (36%) in PIP2 as compared to the Li-Pilo group. In striatal slices, except for the Li, Atro (10 mg/kg) and Li-Atro (10 mg/kg)-Pilo groups which showed a decrease (33 40%) in IP accumulation, no other alteration was detected. The potentiation of the effect of Pilo by Li does not seem to depend on the PI metabolism, but instead on its involvement with muscarinic and dopaminergic systems.
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Affiliation(s)
- M M Marinho
- Department of Pharmacy, Federal University of Ceará, Fortaleza, Brazil
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Asai M, Matamoros-Trejo G, Linares G. Long-term pharmacological kindling increases in vitro release of IR-Met and IR-Leu-enkephalin from amygdala. Comp Biochem Physiol A Mol Integr Physiol 1998; 120:269-75. [PMID: 9773507 DOI: 10.1016/s1095-6433(98)10029-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Met-enkephalin release is increased from amygdala and striatum 1 and 15 days after pharmacological kindling with pentylenetetrazol, following potassium-induced depolarization in vitro via a Ca2+ dependent mechanism. Leu-enkephalin release was only enhanced in amygdala and striatum 1 day after the last seizure. IR-Met-enkephalin amygdala tissue content enhanced 1 and 15 days after seizure. In striatum, we found an IR-Met-enkephalin decrease 35 days after the last stimulus. IR-Leu-enkephalin amygdala tissue content enhanced 1 day after the last seizure, and no significant increases were found in striatum 1, 15 and 35 days after the last seizure. In this paper, we show that opioid peptides release is differentially enhanced in rat brain for several days after the last seizure, thus suggesting that opioid peptides may have a protective action against seizure activity.
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Affiliation(s)
- M Asai
- Laboratorio de Análisis Químicos, Instituto Mexicano de Psiquiatría, Mexico D.F
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24
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Skradski SL, White HS, Ptácek LJ. Genetic mapping of a locus (mass1) causing audiogenic seizures in mice. Genomics 1998; 49:188-92. [PMID: 9598305 DOI: 10.1006/geno.1998.5229] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Frings audiogenic seizure-susceptible mice are a model for sensory-evoked reflex seizures. Their seizure phenotype is characterized by wild running, loss of righting reflex, tonic flexion, and tonic extension in response to high-intensity sound stimulation. The Frings mice represent an inbred colony that has not been genetically characterized. This investigation studied the mode of inheritance for audiogenic seizures by crossing the Frings mouse with the seizure-resistant C57BL/6J mouse. Among the backcross progeny generated by crossing (Frings x C57BL/6J)F1 mice with the Frings strain, 391 of the 836 N2 progeny were audiogenic seizure susceptible, a finding consistent with monogenic inheritance. Genetic mapping and linkage analysis of hybrid mice using MIT microsatellite marker sequences localized the seizure gene, named mass1 for monogenic audiogenic seizure susceptible, to an approximately 3.6 cM interval in the middle of mouse chromosome 13. Linkage of mass1 to chromosome 13 is an important step in identifying the gene associated with a monogenic seizure disorder in mice, which may ultimately lead to a better understanding of the pathophysiology of human seizure disorders.
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Affiliation(s)
- S L Skradski
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City 84112, USA
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25
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Okada M, Hirano T, Mizuno K, Chiba T, Kawata Y, Kiryu K, Wada K, Tasaki H, Kaneko S. Biphasic effects of carbamazepine on the dopaminergic system in rat striatum and hippocampus. Epilepsy Res 1997; 28:143-53. [PMID: 9267779 DOI: 10.1016/s0920-1211(97)00042-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
To clarify the effects of carbamazepine (CBZ) on dopamine (DA) release and their metabolism, the extracellular and total levels of DA, its metabolites (DOPAC and HVA) and precursor, 3,4-dihydroxyphenylalanine (DOPA) in the striatum and hippocampus were studied. DA re-uptake and DOPA accumulation in the striatum and hippocampus, and monoamine oxidase (MAO) activities were also determined. After acute and chronic administrations of CBZ, the plasma concentration of CBZ associated with therapeutic activity increased the extracellular and total levels of all substances determined, whereas supratherapeutic concentration of CBZ decreased extracellular and total levels of all substances. Neither therapeutic nor supratherapeutic concentrations of CBZ affected MAO-A nor -B activities, nor DA re-uptake. DOPA accumulation caused by NSD1015 was inhibited by therapeutic and supratherapeutic concentrations of CBZ. These results suggest that a therapeutic concentration of CBZ enhances DA turnover, whereas a supratherapeutic concentration of CBZ inhibits DA turnover. These effects of CBZ on dopaminergic systems may be, at least partially, involved in the mechanisms of action of CBZ.
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Affiliation(s)
- M Okada
- Department of Neuropsychiatry, Hirosaki University, Japan.
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26
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Shiosaki K, Asin KE, Britton DR, Giardina WJ, Bednarz L, Mahan L, Mikusa J, Nikkel A, Wismer C. Hyperactivity and behavioral seizures in rodents following treatment with the dopamine D1 receptor agonists A-86929 and ABT-431. Eur J Pharmacol 1996; 317:183-90. [PMID: 8997599 DOI: 10.1016/s0014-2999(96)00718-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A-86929 ((-)-trans-9,10-dihydroxy-2-propyl-4,5,5a,6,7,11b-hexahydro-3- thia-5-azacyclopent-1-ena[c]phenanthrene) is a potent and selective full agonist at the dopamine D1 receptor. Both A-86929 and ABT-431 ((-)-trans-9,10-diacetyloxy-2-propyl-4,5,5a,6,7,11b- hexahydro-3-thia-5-azacyclopent-1-ena[c]phenanthrene hydrochloride), the diacetyl prodrug derivative of A-86929, were evaluated for their effects on behavioral excitability in rodents. In rats, A-86929 produced a dose-dependent increase in locomotor activity that was attenuated by the selective dopamine D1 receptor antagonist, SCH 23390, as well as by higher doses of the dopamine D2 receptor antagonist, haloperidol. Repeated administration of A-86929 over 6 days produced hyperactivity which did not change in magnitude across days. Acute administration of A-86929 and ABT-431 to mice produced behavioral seizure activity, with ED50 values of 7.1 and 2.7 mumol/kg, s.c., respectively, that was blocked by SCH 23390. Young rats (35-37 days) exhibited behavioral seizures following A-86929 and ABT-431 treatment (ED50 = 34.2 and 35.6 mumol/kg, s.c., respectively), but at doses higher than those required in mice. Moreover, adult rats (3 months) were less sensitive (ED50 = 345 mumol/kg, s.c.) to A-86929-induced seizures than young rats. Comparison of the ED50 values that produced behavioral seizure activity in rats with those previously established to produce contralateral rotation (ED50 = 0.24 mumol/kg, s.c.) in 6-hydroxydopamine-lesioned rat indicates that a significant dose separation exists between these two properties of A-86929.
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Affiliation(s)
- K Shiosaki
- Pharmaceutical Products Division, Abbott Laboratories, Abbott Park, IL 60064, USA.
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Vriend JP, Alexiuk NA. Effects of valproate on amino acid and monoamine concentrations in striatum of audiogenic seizure-prone Balb/c mice. MOLECULAR AND CHEMICAL NEUROPATHOLOGY 1996; 27:307-24. [PMID: 9147415 DOI: 10.1007/bf02815111] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The effects of valproate on CNS concentrations of gamma-aminobutyric acid (GABA), glulamate (GLU), glutamine (GLN); dopamine (DA), serotonin (5-HT), and metabolites were examined in tissue extracts of caudate nucleus of genetic substrains of Balb/c mice susceptible (EP) or resistant (ER) to audiogenic seizures. Generalized tonic-clonic seizures observed in EP mice were inhibited by valproate, administered 1 h prior to testing, in a dose-response fashion. Concentrations of GABA, GLU, and GLN, which were lower in EP mice than in ER mice, were significantly increased by valproate at doses of 180 and 360 mg/kg. Concentrations of homovanillic acid (HVA) and hydroxyindoleacetic acid (5-HIAA), metabolites of DA and 5-HT, were substantially increased by valproate at these doses. The in situ activity of tyrosine hydroxylase (TH) was not significantly influenced by valproate, whereas a valproate-induced increase in tryptophan hydroxylase (TPH) activity was observed in both striatum and in midbrain tegmentum. The data are consistent with the interpretation that anti-convulsive doses of valproate influences the intraneuronal metabolism of monoamines, GABA, and glutamate concurrently. Valproate's influence on the metabolism of both major inhibitory (GABA) and excitatory (GLY amino acids in striatum could contribute to its anti-convulsive effects in genetically seizure prone mice, as well as to the accumulation of DA and 5-HT metabolites.
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Affiliation(s)
- J P Vriend
- Department of Anatomy, University of Manitoba, Winnipeg, MB, Canada R3E OW3
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Abstract
The clinical benefits of dopamine agonists in the management of epilepsy can be traced back over a century, whilst the introduction of neuroleptics into psychiatry practice 40 years ago witnessed the emergence of fits as a side effect of dopamine receptor blockade. Epidemiologists noticed a reciprocal relationship between the supposed dopaminergic overactivity syndrome of schizophrenia and epilepsy, which came to be regarded as a dopamine underactivity condition. Early pharmacological studies of epilepsy employed nonselective drugs, that often did not permit dopamine's antiepileptic action to be clearly dissociated from that of other monoamines. Likewise, the biochemical search for genetic abnormalities in brain dopamine function, as predeterminants of spontaneous epilepsy, proved largely inconclusive. The discovery of multiple dopamine receptor families (D1 and D2), mediating opposing influences on neuronal excitability, heralded a new era of dopamine-epilepsy research. The traditional anticonvulsant action of dopamine was attributed to D2 receptor stimulation in the forebrain, while the advent of selective D1 agonists with proconvulsant properties revealed for the first time that dopamine could also lower the seizure threshold from the midbrain. Whilst there is no immediate prospect of developing D2 agonists or D1 antagonists as clinically useful antiepileptics, there is a growing awareness that seizures might be precipitated as a consequence of treating other neurological disorders with D2 antagonists (schizophrenia) or D1 agonists (parkinsonism).
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Affiliation(s)
- M S Starr
- Department of Pharmacology, School of Pharmacy, London, United Kingdom
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Alam AM, Starr MS. Regional changes in brain dopamine utilization during status epilepticus in the rat induced by systemic pilocarpine and intrahippocampal carbachol. Neuropharmacology 1996; 35:159-67. [PMID: 8734484 DOI: 10.1016/0028-3908(95)00154-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Systemic administration of pilocarpine (400 mg/kg i.p.) or intrahippocampal injection of carbachol (100 micrograms/1 microliters) induced limbic motor seizures in rats, characterized by head weaving and paw treading, rearing and falling, and forepaw myoclonus, developing into status epilepticus. After being in status for 30 min, rats were killed and levels of dopamine, dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) were determined in eight brain regions by high performance liquid chromatography. Pilocarpine-induced seizures significantly elevated dopamine in the striatum, and in both dorsal and ventral aspects of the hippocampus, but did not affect dopamine in substantia nigra, nucleus accumbens, olfactory tubercle, cingulate cortex or amygdala. Metabolite levels were increased in striatum, substantia, nigra, nucleus accumbens and cingulate cortex, and fell in the hippocampus, but remained unchanged in the olfactory tubercle and amygdala. Intrahippocampal carbachol significantly raised the dopamine contents of striatum and nigra, and in both ventral and dorsal aspects of the hippocampus, but not elsewhere. DOPAC and/or HVA were elevated in all brain regions tested, save for amygdala and dorsal hippocampus. These changes translated into seizure-induced increases in dopamine utilization in the nucleus accumbens, olfactory tubercle and cingulate cortex, and to a fall in dopamine utilisation in the hippocampus, with no net change in amygdala. In addition pilocarpine (but not carbachol) increased dopamine utilization in the nigrostriatal axis, possibly through a seizure-unrelated mechanism. The relevance of these findings to seizure development are discussed.
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Affiliation(s)
- A M Alam
- Department of Pharmacology, School of Pharmacy, London, U.K
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30
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Okada M, Kaneko S, Hirano T, Mizuno K, Kondo T, Otani K, Fukushima Y. Effects of zonisamide on dopaminergic system. Epilepsy Res 1995; 22:193-205. [PMID: 8991786 DOI: 10.1016/0920-1211(95)00078-x] [Citation(s) in RCA: 151] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Effects of zonisamide (ZNS) on extracellular dopamine (DA), its precursor 3,4-dihydroxyphenylalanine (DOPA), its metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) levels in the striatum as well as hippocampus of freely moving rats were studied. Intracellular DA, DOPA, DOPAC and HVA levels, as well as DOPA accumulation as an index of tyrosine hydroxylase activity in the rat brain in vivo, DA re-uptake in the striatum and hippocampus, and monoamine oxidase (MAO) activities were also determined. Acute administrations of therapeutic ZNS doses (20 and 50 mg/kg) increased striatal extracellular DOPA levels, intracellular striatal and hippocampal DOPA levels, and stimulated DOPA accumulation in both brain regions. ZNS also increased striatal and hippocampal intracellular as well as extracellular DA and HVA levels, but decreased those of DOPAC levels. Chronic (3 weeks) administrations of therapeutic ZNS doses (20 and 50 mg/kg/day) increased intracellular DA, DOPA, DOPAC and HVA levels in striatum and hippocampus. ZNS-induced changes were greater in intracellular levels than in extracellular levels. Acute and chronic supratherapeutic ZNS dose (100 mg/kg) administration decreased intracellular levels of all substances detectable in both brain regions, and inhibited DOPA accumulation. Both subtypes of MAO (type A and type B) activities were weakly inhibited by ZNS. ZNS showed no effect on DA re-uptake in striatum nor in hippocampus. These results suggest that therapeutic ZNS doses increase DOPA accumulation as well as both intracellular and extracellular DA, DOPA and HVA levels. However, such doses also decrease extracellular and intracellular DOPAC levels by enhancing DA synthesis and/or by selectively inhibiting MAO-B activities. In addition, chronic therapeutic ZNS dose administration enhances DA synthesis, which results in increased intracellular DA, its precursor and its metabolites levels. On the other hand, both acute and chronic supratherapeutic ZNS dose administrations inhibit DA turnover. These ZNS effects on DA metabolism are at least partly involved in the mechanisms of action of ZNS.
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Affiliation(s)
- M Okada
- Department of Neuropsychiatry, Hirosaki University, Japan
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31
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Starr MS. Glutamate/dopamine D1/D2 balance in the basal ganglia and its relevance to Parkinson's disease. Synapse 1995; 19:264-93. [PMID: 7792721 DOI: 10.1002/syn.890190405] [Citation(s) in RCA: 185] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The recent availability of selective ligands for NMDA and AMPA receptors has enabled neuroscientists to test the hypothesis that Parkinson's disease is a glutamate hyperactivity disorder and hence treatable with glutamate antagonists. This review takes a critical look at the motor characteristics of this new class of drugs in rodent and primate models of parkinsonism and assesses the clinical potential and pitfalls of this radical new approach. Monotherapy of Parkinson's disease with glutamate antagonists appears impractical at the present time, due to their low efficacy and unacceptable side effects, but polypharmacy with L-DOPA and a glutamate antagonist as adjuvant is a more realistic prospect. This review will focus on the ways in which glutamate receptor blockade facilitates motor recovery with L-DOPA and will examine whether the basis for this beneficial effect can be traced to a specific interaction with dopamine at D1 or D2 receptors, and therefore to discrete motor pathways within the basal ganglia.
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Affiliation(s)
- M S Starr
- Department of Pharmacology, School of Pharmacy, London, United Kingdom
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32
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Alam AM, Starr MS. Effects of dopamine D3 receptor agonists on pilocarpine-induced limbic seizures in the rat. Neuroscience 1994; 60:1039-47. [PMID: 7936204 DOI: 10.1016/0306-4522(94)90281-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The discrete localization of D3 receptors in the nucleus accumbens and subjacent islands of Calleja bears a close resemblance to the dopamine-sensitive anticonvulsant site in the anteroventral striatum. To determine if these D3 receptors were capable of attenuating limbic motor seizures induced by pilocarpine, dopamine agonists with preferential or non-selective D3 affinity were injected stereotaxically into these limbic brain regions of the rat via indwelling cannulae prior to pilocarpine challenge. Reliable clonic seizures were obtained by administering the proconvulsive dopamine D1 agonist SKF 38393 (10 mg/kg i.p.) followed by a subconvulsant dose of pilocarpine (280-300 mg/kg i.p.). Bilateral intra-accumbens pretreatment with the D3 > D2 agonist RU 24213 (0.2 pmol-7 nmol) significantly delayed the onset of seizures, with a minimum effective dose of 2 pmol, without altering their frequency or severity. The more selective D3 agonist LY 171555 (0.2 pmol-7.8 nmol) was less potent, and only attenuated pilocarpine-induced seizures at a dose (500 pmol) that would have stimulated accumbens D2 receptors as well. Intra-accumbens injections of the highly potent and selective D3 agonist 7-OH-DPAT (20 pmol to 7 nmol) afforded no protection against pilocarpine-induced seizures. Apomorphine, a mixed D1/D2/D3 agonist, delayed seizure onset at 100-500 pmol, but not at higher doses. RU 24213, LY 171555 and 7-OH-DPAT were all modestly anticonvulsant when microinjected into the islands of Calleja at D2/D3 unselective doses. These data support the notion that dopamine systems limit seizure propagation through the limbic forebrain, but suggest this protective effect is mediated by D2 rather than D3 receptors.
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Affiliation(s)
- A M Alam
- Department of Pharmacology, School of Pharmacy, London, U.K
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Starr MS, Starr BS. Comparison of the effects of NMDA and AMPA antagonists on the locomotor activity induced by selective D1 and D2 dopamine agonists in reserpine-treated mice. Psychopharmacology (Berl) 1994; 114:469-76. [PMID: 7855205 DOI: 10.1007/bf02249338] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
This study examined the interaction between various glutamate antagonists and selective D1 (SKF 38393) and D2 (RU 24213) dopamine agonists in the production of locomotion in the reserpine-treated mouse. Firstly, in normal mice, the NMDA channel blocker MK 801 (0.1-1.6 mg/kg) caused a biphasic stimulation/depression of locomotor activity, whereas the competitive NMDA antagonists CGP 40116 (0.25-8 mg/kg) and CPP (0.2-20 mg/kg), and the NMDA glycine site antagonist HA 966 (0.4-10 mg/kg) inhibited locomotion monophasically. These compounds caused varying degrees of muscle weakness and impairment of posture and gait, whilst the AMPA receptor blocker NBQX (0.2-25 mg/kg) had no significant effect on unconditioned mouse motor behaviour. None of the antagonists reversed reserpine-induced akinesia by themselves, but they all potentiated the locomotor movements induced by 30 mg/kg SKF 38393. Movements remained fluent with low doses of CPP, HA 966 and NBQX, but became ataxic with MK 801 and CGP 40116, with sedation prevailing at high doses of all the antagonists, as in normal mice. CPP and NBQX also combined synergistically with SKF 38393 to promote tonic convulsions. By contrast, RU 24213-induced locomotion was dose-dependently depressed by MK 801, CGP 40116 and HA 966, but was unaffected by CPP or NBQX. These differential effects of NMDA and AMPA antagonists on D1 and D2 motor responding in the monoamine-depleted mouse are discussed in terms of possible mechanisms and sites of action within the brain, and the implications for their putative use as adjuvants to L-dopa in antiparkinson therapy.
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Affiliation(s)
- M S Starr
- Department of Pharmacology, School of Pharmacy, London, UK
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34
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Ring HA, Trimble MR, Costa DC, Moriarty J, Verhoeff NP, Ell PJ. Striatal dopamine receptor binding in epileptic psychoses. Biol Psychiatry 1994; 35:375-80. [PMID: 8018783 DOI: 10.1016/0006-3223(94)90003-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In order to study the nature of dopaminergic activity in epileptic psychoses we investigated striatal dopamine receptor binding in 14 patients with epilepsy. Seven of the patients were acutely psychotic when studied, having recently developed a periictal schizophreniform psychosis. The remaining patients were not psychotic. All patients were scanned using single photon emission tomography (SPET) with 123I-IBZM, a specific dopamine D2 receptor ligand. A region of interest analysis was performed. Comparison of mean basal ganglia to occipital cortex activity ratios in the two groups demonstrated significantly reduced specific binding of 123I-IBZM to striatal D2 receptors in the psychotic patients compared to those without psychosis.
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Affiliation(s)
- H A Ring
- Raymond Way Neuropsychiatry Research Group, Institute of Neurology, London, England
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35
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Gelbard HA, Applegate CD. Persistent increases in dopamine D2 receptor mRNA expression in basal ganglia following kindling. Epilepsy Res 1994; 17:23-9. [PMID: 8174522 DOI: 10.1016/0920-1211(94)90076-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Amygdala kindling resulted in significant increases in the expression of D2 receptor mRNA in the nucleus accumbens and striatum 30 days following the last kindling stimulation. Densitometric analyses of tissue sections incubated in the presence of an oligonucleotide probe directed against D2 receptor cDNA indicated a 20-35% increase in D2 receptor mRNA in these regions following kindling. Kindling from the amygdala followed by piriform cortical kindling in the transfer paradigm (overkindling) resulted in significant further increases in D2 receptor mRNA expression in both the accumbens (150% increase) and striatum (120% increase). There were no observed hemispheric asymmetries in D2 receptor mRNA in either kindled or overkindled animals. The data indicate an enduring upregulation of extrapyramidal D2 receptor mRNA following the kindling process. How this change may relate to kindling-induced alterations in seizure susceptibility or behaviors mediated by limbic dopaminergic pathways are questions for future studies.
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Affiliation(s)
- H A Gelbard
- Department of Neurology, University of Rochester Medical Center, NY 14642
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36
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Cavalheiro EA, Fernandes MJ, Turski L, Naffah-Mazzacoratti MG. Spontaneous recurrent seizures in rats: amino acid and monoamine determination in the hippocampus. Epilepsia 1994; 35:1-11. [PMID: 8112229 DOI: 10.1111/j.1528-1157.1994.tb02905.x] [Citation(s) in RCA: 159] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Rats subjected to structural brain damage induced by sustained convulsions triggered by systemic administration of pilocarpine (PILO) are a useful model for investigation of the mechanisms essential for seizure generation and spread in rodents. After PILO administration, three distinct phases are observed: (a) an acute period of 1-2 days' duration corresponding to a pattern of repetitive limbic seizures and status epilepticus; (b) a seizure-free (silent) period characterized by a progressive return to normal EEG and behavior of 4-44 days' duration; and (c) a period of spontaneous recurrent seizures (SRS) starting 5-45 days after PILO administration and lasting throughout the animal's life. PILO (320-350 mg/kg intraperitoneally, i.p.) was administered to rats, and the content of hippocampal monoamines and amino acids was measured in the acute, silent, and SRS periods by liquid chromatography. Norepinephrine (NE) level was decreased during all periods whereas dopamine (DA) content was increased. Serotonin (5-hydroxytryptamine, 5-HT) was increased only in the acute period. Utilization rate measurement of monoamines showed increased NE consumption and decreased DA consumption during all phases. 5-HT utilization rate was increased only in the acute period. Amino acid content showed a decrease in aspartate (ASP) and glutamate (GLU) concentrations associated with increased gamma-aminobutyric acid (GABA) level during the acute period. The silent phase was characterized by a decrease in glycine (GLY) and GABA levels and an increase in GLU concentration. The SRS period showed an increase in all amino acid concentrations. These findings show important neurochemical changes in the course of establishment of an epileptic focus after brain damage induced by status epilepticus triggered by pilocarpine.
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Affiliation(s)
- E A Cavalheiro
- Disciplina de Neurologia Experimental, Escola Paulista de Medicina, São Paulo, Brazil
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37
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POSTER COMMUNICATIONS. Br J Pharmacol 1993; 110:81P-184P. [DOI: 10.1111/j.1476-5381.1993.tb16292.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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38
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al-Tajir G, Starr MS. Disordered dopamine neurotransmission in the striatum of rats undergoing pilocarpine-induced generalized seizures, as revealed by microdialysis. JOURNAL OF NEURAL TRANSMISSION. PARKINSON'S DISEASE AND DEMENTIA SECTION 1993; 5:89-100. [PMID: 8101446 DOI: 10.1007/bf02251199] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In this study rats were fitted with a concentric dialysis probe in one striatum and extracellular concentrations of dopamine and HVA measured by reverse phase high performance liquid chromatography. Injections of saline or the D1 agonist SKF 38393 (30 mg/kg) did not affect the releases of these compounds. On the other hand, the D2 agonist LY 171555 (0.5 mg/kg) inhibited the release of both dopamine and HVA, whilst amphetamine (1 mg/kg) increased the output of dopamine but not HVA. Treatment with 200 mg/kg pilocarpine caused minimal signs of epileptic activity and did not affect striatal dopamine neurotransmission. Concomitant administration of SKF 38393 (30 mg/kg) to this dose of pilocarpine greatly facilitated the incidence and severity of motor seizures, which were accompanied by an irregular pattern of dopamine release and a significant rise in HVA overflow. Similar results were obtained with rats made to convulse with 400 mg/mg pilocarpine, and to a lesser extent if these animals were first pretreated with a protective dose of LY 171555 (0.5 mg/kg). It is concluded that dopamine neurotransmission in the striatum is disrupted in rats undergoing a pilocarpine-induced motor seizure, and that the extent of this disruption increases as the seizure becomes more severe. An irregular release of dopamine could signify a loss of sensorimotor control by the striatum, which might conceivably contribute to the intractability of the seizure. An increase in the dialysate concentrations of metabolite and not dopamine, is consistent with a heightened glutamate-stimulated release of dopamine from a discrete striatal pool, caused by the seizure spreading through the cortex and activating the cortico-striatal system.
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Affiliation(s)
- G al-Tajir
- Department of Pharmacology, School of Pharmacy, London, United Kingdom
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39
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Starr MS, Starr BS. Glutamate-dopamine interactions in the production of pilocarpine motor seizures in the mouse. JOURNAL OF NEURAL TRANSMISSION. PARKINSON'S DISEASE AND DEMENTIA SECTION 1993; 6:109-17. [PMID: 7906944 DOI: 10.1007/bf02261004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
An assortment of glutamate antagonists with differing selectivities for NMDA and AMPA-type glutamate receptors, were tested for their effects in the mouse pilocarpine model of complex partial seizures. MK 801 (0.1-0.8 mg/kg) and high doses of HA 966 (50 mg/kg) were proconvulsant, whilst CGP 40116 (1-8 mg/kg) and low doses of HA 966 (0.4-10 mg/kg) inhibited pilocarpine-induced convulsions. CPP (5-20 mg/kg) and NBQX (1-50 mg/kg) were without effect. The dopamine D1 agonist SKF 38393 (10 mg/kg) facilitated the convulsant effects of low-dose pilocarpine (100 mg/kg). MK 801 (0.1-0.2 mg/kg) and HA 966 (50 mg/kg) interacted synergistically with SKF 38393 to promote the proconvulsant effects of D1 stimulation, whilst CPP (10-20 mg/kg) and HA 966 (10 mg/kg) had the opposite effect. CGP 40116 and NBQX were without effect. These results show that the convulsant qualities of MK 801 and SKF 38393, that have been detected in animal models of Parkinson's disease, can be reproduced in the pilocarpine model of epilepsy. Whilst the glutamate antagonists all interact synergistically with SKF 38393 to improve its antiparkinson activity, only MK 801 and high doses of HA 966 similarly potentiate the convulsions associated with D1 stimulation. An appropriate mixture of a glutamate antagonist and a D1 agonist could theoretically be used beneficially in the treatment of Parkinson's disease, without causing epilepsy as a side effect.
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Affiliation(s)
- M S Starr
- Department of Pharmacology, School of Pharmacy, London, United Kingdom
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40
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Vriend J, Alexiuk NA, Green-Johnson J, Ryan E. Determination of amino acids and monoamine neurotransmitters in caudate nucleus of seizure-resistant and seizure-prone BALB/c mice. J Neurochem 1993; 60:1300-7. [PMID: 7681100 DOI: 10.1111/j.1471-4159.1993.tb03290.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Amino acid and monoamine concentrations were examined in tissue extracts of caudate nucleus of genetic substrains of BALB/c mice susceptible or resistant to audiogenic seizures. Amino acids [aspartate, glutamate, glycine, taurine, serine, gamma-aminobutyric acid (GABA)], monoamines, and related metabolites were separated by isocratic reverse-phase chromatography and detected by a coulometric electrode array system. In situ activity of tyrosine hydroxylase and tryptophan hydroxylase were determined by measuring the accumulation of L-DOPA and 5-hydroxytryptophan after administration of the decarboxylase inhibitor NSD-1015. Highly significant decreases in concentrations of both excitatory (glutamate and aspartate) and inhibitory amino acids (GABA and taurine) were observed in extracts of caudate nucleus of seizure-prone mice. Substantial decreases in concentrations of dopamine (DA) and its metabolites, 3,4-dihydroxyphenylacetic acid and homovanillic acid, were also noted. Decreased accumulation of L-DOPA after NSD-1015 administration provided evidence for decreased tyrosine hydroxylase activity and decreased DA synthesis in striatum of seizure-prone mice compared with seizure-resistant mice. Decreased concentrations of the DA metabolite 3-methoxytyramine (after NSD-1015 administration) suggested that DA release was also compromised in seizure-prone mice. No significant difference in 5-hydroxytryptophan accumulation in striatum of seizure-prone and seizure-resistant mice suggested that tryptophan hydroxylase activity and serotonin synthesis were not affected. The data suggest that seizure-prone BALB/c mice have a deficiency in intracellular content of both excitatory and inhibitory amino acids. The data also raise the issue of whether GABAergic interactions with the nigrostriatal DA system are important in the regulation of audiogenic seizure susceptibility.
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Affiliation(s)
- J Vriend
- Department of Anatomy, University of Manitoba, Winnipeg, Canada
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41
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Alam AM, Starr MS. Dopaminergic modulation of pilocarpine-induced motor seizures in the rat: the role of hippocampal D2 receptors. Neuroscience 1993; 53:425-31. [PMID: 8098511 DOI: 10.1016/0306-4522(93)90206-u] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
This study examined the role of hippocampal dopamine D2 receptors in the genesis of limbic seizures induced by muscarinic agonists in the rat. Pilocarpine, 600 mg/kg, elicited rapid and usually fatal convulsions. These were not affected by focal injections of saline (1 microliter) into both hippocampi. Pretreatment of the dorsal, but not the lateral hippocampus, with the D2 agonist trans-(+)-4,4a,5,6,7,8,8a,9-octahydro-5-propyl-2H-pyrazolo-(3,4-g)quinol ine hydrochloride (LY 171555, 2 micrograms per side), did not alter the frequency of pilocarpine-induced convulsions, but significantly delayed their appearance and reduced their intensity. LY 171555 similarly increased the latency of seizures induced by focal hippocampal injection of carbachol (100 micrograms), without changing the frequency or the severity. The selective D2 antagonist raclopride, injected dorsally into both hippocampi dose-dependently facilitated motor seizures evoked by pilocarpine (100 mg/kg), the cholinomimetic at this dose being ineffective as a convulsant in saline-treated animals. Intrahippocampal administration of the D1 agonist 2,3,4,5-tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine hydrochloride (SKF 38393, 2 micrograms per side) did not facilitate pilocarpine seizures and did not potentiate the proconvulsant action of raclopride. These data demonstrate that activation of the dopaminergic system, via D2 receptors in the dorsal hippocampus, is capable of protecting the animal against limbic motor seizures arising from excessive muscarinic stimulation of the hippocampus. Since the blockade of D2 receptors in the hippocampus markedly lowered the seizure threshold to pilocarpine, this would suggest that the dopaminergic input to the hippocampus is normally tonically active and functions physiologically to prevent epileptogenesis.
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Affiliation(s)
- A M Alam
- Department of Pharmacology, School of Pharmacy, Brunswick Square, London, U.K
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42
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Starr MS, Starr BS. Seizure promotion by D1 agonists does not correlate with other dopaminergic properties. JOURNAL OF NEURAL TRANSMISSION. PARKINSON'S DISEASE AND DEMENTIA SECTION 1993; 6:27-34. [PMID: 8105796 DOI: 10.1007/bf02252620] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A range of D1 receptor agonists were tested for their ability to facilitate limbic motor seizures induced by a subthreshold dose of the chemoconvulsant pilocarpine (100 mg/kg IP) in mice. ED50 values (mumol/kg) were calculated from log dose-probit analyses, giving relative proconvulsant potencies of SKF 82958 > CY 208-243 > SKF 77434 = SKF 75670 = SKF 80723 > SKF 38393. The compound SKF 82526, which poorly crosses the blood-brain barrier, did not lower the seizure threshold. Convulsions consisted of rearing and forepaw myoclonus, leading to status epilepticus at higher doses of the D1 agonists. No deaths were recorded. A maximum seizure incidence of 50% was obtained with SKF 75670, compared to 100% for the other compounds. Apart from SKF 82526, the D1 agonists all elicited behavioural signs of central D1 receptor stimulation, including motor restlessness, grooming and sniffing. There was no obvious relationship between the abilities of these D1 agonist drugs to promote epilepsy and their effects on unconditioned motor behaviour, or their affinities and efficacies at the striatal D1 receptor. It is concluded that a reduction of the seizure threshold is an inevitable consequence of central D1 receptor stimulation with existing D1 agonists.
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Affiliation(s)
- M S Starr
- Department of Pharmacology, School of Pharmacy, London, United Kingdom
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43
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Alam AM, Starr MS. Dopaminergic modulation of pilocarpine-induced motor seizures in the rat: the role of hippocampal dopamine D1 receptors. Eur J Pharmacol 1992; 222:227-32. [PMID: 1451735 DOI: 10.1016/0014-2999(92)90860-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The present study addressed the role of dopamine D1 receptors in pilocarpine-induced motor seizures in rats. Bilateral pretreatment of the hippocampus with the D1 agonist SKF 38393 (0.1-5 micrograms) did not alter the animals' sensitivity to a threshold (200 mg/kg i.p.) or fully convulsant dose (600 mg/kg i.p.) of pilocarpine, as compared to hippocampal saline-treated controls. Similarly, direct injection of pilocarpine (200 micrograms per side) into both hippocampi elicited low level seizure activity that was not modified by SKF 38393, either coadministered (2 micrograms per side) or injected systemically (30 mg/kg i.p.). On the other hand, intrahippocampal microinjections of the D1 antagonist, SCH 23390 (2 micrograms per side), whilst unable to prevent epileptogenesis to 600 mg/kg pilocarpine, delayed the onset of seizures and reduced their severity. These results suggest that hippocampal dopamine lowers the seizure threshold by activating D1 receptors, an effect which is only disclosed by D1 receptor blockade and is not surmountable by additional D1 stimulation.
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Affiliation(s)
- A M Alam
- Department of Pharmacology, School of Pharmacy, London, UK
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Cepeda C, Radisavljevic Z, Peacock W, Levine MS, Buchwald NA. Differential modulation by dopamine of responses evoked by excitatory amino acids in human cortex. Synapse 1992; 11:330-41. [PMID: 1354399 DOI: 10.1002/syn.890110408] [Citation(s) in RCA: 132] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The responses of human neocortical neurons to iontophoretic application of excitatory amino acids and their modulation by dopamine (DA) were studied in vitro. Brain slices were obtained from children undergoing surgery for intractable epilepsy. Application of N-methyl-D-aspartate (NMDA) to the slices induced slow depolarizations accompanied by decreased input conductances and sustained action potentials in cortical neurons. Glutamate produced rapid depolarizations and firing with few changes in input conductances. Quisqualate also induced depolarization and firing, but input conductances increased during the rising phase of the membrane depolarization. Iontophoretic application of DA alone produced no change in membrane potential or input conductance. However, when DA was applied in conjunction with the excitatory amino acids, it produced contrasting effects. With either bath application of DA or when iontophoresis of DA preceded application of NMDA, the amplitude of the membrane depolarizations and the number of action potentials were increased, whereas the latency of these responses decreased. In contrast, DA decreased the amplitude of the depolarizations and the number of action potentials evoked by glutamate or quisqualate. The fact that DA affects responses to NMDA and glutamate or quisqualate in opposite directions is of considerable importance to the understanding of cellular mechanisms of neuromodulation and the role of DA in cognitive processing and in epilepsy.
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Affiliation(s)
- C Cepeda
- Mental Retardation Research Center, University of California, Los Angeles 90024-1759
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45
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Daly SA, Waddington JL. Two directions of dopamine D1/D2 receptor interaction in studies of behavioural regulation: a finding generic to four new, selective dopamine D1 receptor antagonists. Eur J Pharmacol 1992; 213:251-8. [PMID: 1387846 DOI: 10.1016/0014-2999(92)90689-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A range of new, chemically distinct D1 dopamine receptor antagonists, SCH 39166, NO 756, A-69024 and BW 737C, were studied for their effects on behavioural responses to the selective D2 agonist RU 24213. Each D1 antagonist not only blocked typical sniffing and locomotor responses to RU 24213 but also released atypical myoclonic jerking behaviour, while the selective D2 antagonist YM 09151 blocked these typical responses but did not release jerking. The rank order of effectiveness of these D1 antagonists to release such D2 agonist-induced jerking was similar to that of their selectivities as D1 antagonists; also, the action of BW 737C showed complete enantioselectivity, the inactivity of its R-antipode BW 736C paralleling enantioselective blockade of D1 but not D2 receptors. It appears that while tonic activity through D1 receptors is necessary for the expression of typical D2-stimulated behaviour, via well-known cooperative/synergistic D1:D2 interactions, D1 tone also normally inhibits, via oppositional D1:D2 interactions, the expression of atypical D2-stimulated behaviours such as jerking. Oppositional D1:D2 interactions are evident using all of the classes of selective D1 antagonist currently known, and appear to constitute another general mode of dopaminergic regulation.
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Affiliation(s)
- S A Daly
- Department of Clinical Pharmacology, Royal College of Surgeons, Dublin, Ireland
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46
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Kebabian JW, DeNinno MP, Schoenleber R, MacKenzie R, Britton DR, Asin KE. A68930: A potent agonist specific for the dopamine D1 receptor. Neurochem Int 1992; 20 Suppl:157S-160S. [PMID: 1365416 DOI: 10.1016/0197-0186(92)90230-o] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A68930, [1R, 3S] 1-aminomethyl-5,6-dihydroxy-3-phenylisochroman HCl, is a potent, partial agonist in the dopamine-sensitive adenylate cyclase model of the D1 dopamine receptor in fish retina. In the rat caudate-putamen model of the D1 dopamine receptor, A68930 is a potent (EC50 2.1 nM) full agonist. In contrast, A68930 is a much weaker (EC50 = 3,920 nM) full agonist in a biochemical model of the D2 dopamine receptor. A68930 also displays weak 2 agonist activity but the molecule is virtually inactive at the 1 and beta-adrenoceptors. When tested in rats bearing a unilateral 6-OHDA lesion of the nigro-neostriatal neurons, A68930 elicits prolonged (> 20 hr) contralateral turning.
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Affiliation(s)
- J W Kebabian
- Neuroscience Research Division, Abbott Laboratories, Abbott Park, IL 60061
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47
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Wahnschaffe U, Löscher W. Anticonvulsant effects of ipsilateral but not contralateral microinjections of the dopamine D2 agonist LY 171555 into the nucleus accumbens of amygdala-kindled rats. Brain Res 1991; 553:181-7. [PMID: 1681980 DOI: 10.1016/0006-8993(91)90822-d] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Recent radioligand binding studies demonstrated an increase in the density of dopamine D2 receptors in the nucleus accumbens ipsilateral to the stimulating electrode in amygdala- or hippocampal-kindled rats. In the present study we examined the anticonvulsant effect of dopamine agonists by unilateral microinjections into the nucleus accumbens in rats kindled from the right basolateral amygdaloid nucleus. Microinjections of the D2 agonist LY 171555 into the ipsilateral nucleus accumbens 15 min prior to the kindling stimulation in fully kindled rats decreased significantly kindling parameters such as seizure severity, seizure duration and afterdischarge duration, whereas the D1 agonist SKF 38393 had no anticonvulsant effects. After ipsilateral microinjection of 40 pmol LY 171555 focal and generalized kindled seizures were totally blocked in almost 50% of the rats. The anticonvulsant effect of LY 171555 could be completely antagonised by systemic administration of the D2 antagonist sulpiride. Microinjection of the D1 or D2 agonist into the nucleus accumbens contralateral to the stimulating electrode had no anticonvulsant effects. In accordance with other reports our data indicate a possible topographic limitation of D2 receptor mediated anticonvulsant effects to specific regions of the basal ganglia.
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MESH Headings
- 2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine/administration & dosage
- 2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine/pharmacology
- Amygdala/physiology
- Animals
- Anticonvulsants/administration & dosage
- Anticonvulsants/pharmacology
- Dopamine Agents/pharmacology
- Electric Stimulation
- Ergolines/administration & dosage
- Ergolines/pharmacology
- Female
- Functional Laterality
- Kindling, Neurologic
- Microinjections
- Nucleus Accumbens/drug effects
- Nucleus Accumbens/physiology
- Quinpirole
- Rats
- Rats, Inbred Strains
- Receptors, Dopamine/drug effects
- Receptors, Dopamine/physiology
- Receptors, Dopamine D2
- Seizures/physiopathology
- Sulpiride/administration & dosage
- Sulpiride/pharmacology
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Affiliation(s)
- U Wahnschaffe
- Department of Pharmacology, Toxicology and Pharmacy, School of Veterinary Medicine, Hannover, F.R.G
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48
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DeNinno MP, Schoenleber R, MacKenzie R, Britton DR, Asin KE, Briggs C, Trugman JM, Ackerman M, Artman L, Bednarz L. A68930: a potent agonist selective for the dopamine D1 receptor. Eur J Pharmacol 1991; 199:209-19. [PMID: 1683288 DOI: 10.1016/0014-2999(91)90459-4] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A68930, (1R,3S)-1-aminomethyl-5,6-dihydroxy-3-phenylisochroman HCl, is a potent (EC50 = 2.5 nM), partial (intrinsic activity = 66% of dopamine) agonist in the fish retina dopamine-sensitive adenylate cyclase model of the D1 dopamine receptor. In the rat caudate-putamen model of the D1 dopamine receptor, A68930 is a potent (EC50 = 2.1 nM) full agonist. In contrast, A68930 is a much weaker (EC50 = 3920 nM) full agonist in a biochemical model of the dopamine D2 receptor. The orientation of the 3-phenyl substituent in the molecule is critical for the affinity and selectivity of the molecule towards the dopamine D1 receptor. A68930 also displays weak alpha 2-agonist activity but the molecule is virtually inactive at the alpha 1- and beta-adrenoceptors. When tested in rats bearing a unilateral 6-OHDA lesion of the nigro-neostriatal neurons, A68930 elicits prolonged (greater than 20 h) contralateral turning that is antagonized by dopamine D1 receptor selective doses of SCH 23390 but not by D2 receptor selective doses of haloperidol. In this lesioned rat model, A68930 increases 2-deoxyglucose accumulation in the lesioned substantia nigra, pars reticulata. When tested in normal rats, A68930 elicits hyperactivity and, at higher doses, produces a forelimb clonus.
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MESH Headings
- Adenylyl Cyclases/metabolism
- Animals
- Benzazepines/pharmacology
- Binding Sites
- Carps
- Chromans/metabolism
- Chromans/pharmacology
- Deoxyglucose/metabolism
- Dopamine Agents/metabolism
- Dopamine Agents/pharmacology
- Haloperidol/pharmacology
- Male
- Motor Activity/drug effects
- Oxidopamine/metabolism
- Oxidopamine/pharmacology
- Rats
- Rats, Inbred Strains
- Receptors, Adrenergic, alpha/drug effects
- Receptors, Adrenergic, alpha/metabolism
- Receptors, Adrenergic, beta/drug effects
- Receptors, Adrenergic, beta/metabolism
- Receptors, Dopamine/drug effects
- Receptors, Dopamine/metabolism
- Receptors, Dopamine D1
- Seizures/chemically induced
- Substantia Nigra/drug effects
- Substantia Nigra/metabolism
- Substantia Nigra/physiology
- Tumor Cells, Cultured
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Affiliation(s)
- M P DeNinno
- Neuroscience Research Division, Abbott Laboratories, Abbott Park, IL 60064
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49
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al-Tajir G, Starr MS. D-2 agonists protect rodents against pilocarpine-induced convulsions by stimulating D-2 receptors in the striatum, but not in the substantia nigra. Pharmacol Biochem Behav 1991; 39:109-13. [PMID: 1924492 DOI: 10.1016/0091-3057(91)90405-q] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
This study employed the pilocarpine model of epilepsy to determine the relative systemic anticonvulsant potencies of five different D-2 agonists in the mouse, and to investigate the site of anticonvulsant action of LY 171555 in the rat's brain following intracerebral microinjection. Control mice pretreated with saline developed motor seizures when challenged with pilocarpine (400 mg/kg, 11/13 convulsed). D-2 agonists protected mice against pilocarpine-induced seizures in the rank order of potency PHNO greater than pergolide greater than greater than lisuride = LY 171555 much greater than RU 24213, with ED50 values ranging from 0.17 mg/kg for PHNO to greater than 4.5 mg/kg for RU 24213. The response to LY 171555 was abolished by the D-2 blocker metoclopramide (1.25 mg/kg), but not by the D-1 antagonist SCH 23390 (0.25 mg/kg). All D-2 agonists induced head-down sniffing and forward locomotion, consistent with central D-2 activation. LY 171555 (ED50 0.19 mg/kg), but not RU 24213 (ED50 greater than 4.5 mg/kg), was similarly efficacious in the rat. When injected into both hemispheres of the conscious rat via indwelling cannulae, intrastriatal saline failed to afford protection against the convulsant action of pilocarpine (600 mg/kg, 13/15 convulsed), whereas LY 171555 did (1 microgram, 1/12 convulsed). Intrastriatal RU 24213 (1 microgram per side) was without effect (7/10 convulsed). Similarly, no protection resulted when saline (15/16 convulsed) or LY 171555 (1 microgram, 17/23 convulsed) were delivered into both nigras. It is concluded that in this model of limbic seizures in the mouse and rat, D-2 agonists exert a powerful anticonvulsant effect which is mediated by D-2 receptors in the striatum, but not by D-2 receptors in the substantia nigra.
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Affiliation(s)
- G al-Tajir
- Department of Pharmacology, School of Pharmacy, London, UK
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50
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Abbott B, Starr BS, Starr MS. CY 208-243 behaves as a typical D-1 agonist in the reserpine-treated mouse. Pharmacol Biochem Behav 1991; 38:259-63. [PMID: 1676166 DOI: 10.1016/0091-3057(91)90275-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The object of this study was to determine if the newly developed phenanthridine derivative, CY 208-243, retains its apparent in vivo preference for dopamine D-1 receptors under conditions of dopamine depletion, as a starting point to understanding why CY 208-243 possesses antiparkinson activity and the selective D-1 agonist SKF 38393 does not. Three hours after receiving reserpine (5 mg/kg), mice were strongly sedated and completely unresponsive to the motor stimulant effects of CY 208-243 (0.1-10 mg/kg) or the selective D-2 agonist RU 24213 (0.5-5 mg/kg) administered alone. After 24 h reserpine, the akinesia was partially and dose-dependent reversed by both CY 208-243 (0.1-10 mg/kg) and RU 24213 (0.5-5 mg/kg) alone. CY 208-243 also stimulated rearing and grooming, while RU 24213 gave rise to strong head-down sniffing. The response to 1 mg/kg CY 208-243 was practically abolished by pretreatment with the D-1 antagonist SCH 23390 (0.2 mg/kg). On the other hand, blocking D-2 receptors with metoclopramide (0.25 mg/kg) unexpectedly facilitated CY 208-243-induced locomotion and rearing, but suppressed grooming. When CY 208-243 (1 mg/kg) was injected together with RU 24213 (0.5-5 mg/kg), the two drugs interacted synergistically to stimulate locomotion at all times after reserpine. These animals also exhibited a greater preponderance of grooming, sniffing, gnawing and oral dyskinesia. Apart from the potentiation of some elements of CY 208-243-stimulated motor behaviour by D-2 blockade, these results are qualitatively indistinguishable from those previously obtained with the prototype D-1 agonist SKF 38393.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- B Abbott
- Department of Pharmacology, School of Pharmacy, London, UK
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