1
|
Deidda G, Crunelli V, Di Giovanni G. 5-HT/GABA interaction in epilepsy. PROGRESS IN BRAIN RESEARCH 2021; 259:265-286. [PMID: 33541679 DOI: 10.1016/bs.pbr.2021.01.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Epilepsy is a neurological condition characterized by synchronous neuronal oscillations (seizures) in the electroencephalogram. Seizures are classified in focal or generalized (depending on the brain territory interested during seizures), and in convulsive and/or not convulsive (depending on the presence or not of involuntary movements). The current pharmacological treatments are mainly based on GABA modulation although different neurotransmitters are also involved in epilepsy, including serotonin. However despite much extensive progress in the understanding of epilepsy mechanisms, still, a percentage of people with epilepsy are pharmaco-resistant calling for the need for new therapeutic targets. Here we review preclinical and human evidence showing that serotonin modulates epilepsy that this likely happens via a major modulation/interaction with GABA.
Collapse
Affiliation(s)
- Gabriele Deidda
- Laboratory of Neurophysiology, Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta.
| | - Vincenzo Crunelli
- Laboratory of Neurophysiology, Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta; Neuroscience Division, School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Giuseppe Di Giovanni
- Laboratory of Neurophysiology, Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta; Neuroscience Division, School of Biosciences, Cardiff University, Cardiff, United Kingdom
| |
Collapse
|
2
|
Svob Strac D, Pivac N, Smolders IJ, Fogel WA, De Deurwaerdere P, Di Giovanni G. Monoaminergic Mechanisms in Epilepsy May Offer Innovative Therapeutic Opportunity for Monoaminergic Multi-Target Drugs. Front Neurosci 2016; 10:492. [PMID: 27891070 PMCID: PMC5102907 DOI: 10.3389/fnins.2016.00492] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2016] [Accepted: 10/13/2016] [Indexed: 12/22/2022] Open
Abstract
A large body of experimental and clinical evidence has strongly suggested that monoamines play an important role in regulating epileptogenesis, seizure susceptibility, convulsions, and comorbid psychiatric disorders commonly seen in people with epilepsy (PWE). However, neither the relative significance of individual monoamines nor their interaction has yet been fully clarified due to the complexity of these neurotransmitter systems. In addition, epilepsy is diverse, with many different seizure types and epilepsy syndromes, and the role played by monoamines may vary from one condition to another. In this review, we will focus on the role of serotonin, dopamine, noradrenaline, histamine, and melatonin in epilepsy. Recent experimental, clinical, and genetic evidence will be reviewed in consideration of the mutual relationship of monoamines with the other putative neurotransmitters. The complexity of epileptic pathogenesis may explain why the currently available drugs, developed according to the classic drug discovery paradigm of "one-molecule-one-target," have turned out to be effective only in a percentage of PWE. Although, no antiepileptic drugs currently target specifically monoaminergic systems, multi-target directed ligands acting on different monoaminergic proteins, present on both neurons and glia cells, may represent a new approach in the management of seizures, and their generation as well as comorbid neuropsychiatric disorders.
Collapse
Affiliation(s)
| | - Nela Pivac
- Division of Molecular Medicine, Rudjer Boskovic InstituteZagreb, Croatia
| | - Ilse J. Smolders
- Department of Pharmaceutical Chemistry and Drug Analysis, Vrije Universiteit BrusselBrussels, Belgium
| | - Wieslawa A. Fogel
- Department of Hormone Biochemistry, Medical University of LodzLodz, Poland
| | | | - Giuseppe Di Giovanni
- Laboratory of Neurophysiology, Department of Physiology and Biochemistry, University of MaltaMsida, Malta
| |
Collapse
|
3
|
Puzerey PA, Kodama NX, Galán RF. Abnormal cell-intrinsic and network excitability in the neocortex of serotonin-deficient Pet-1 knockout mice. J Neurophysiol 2015; 115:813-25. [PMID: 26609119 DOI: 10.1152/jn.00996.2014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 11/24/2015] [Indexed: 12/18/2022] Open
Abstract
Neurons originating from the raphe nuclei of the brain stem are the exclusive source of serotonin (5-HT) to the cortex. Their serotonergic phenotype is specified by the transcriptional regulator Pet-1, which is also necessary for maintaining their neurotransmitter identity across development. Transgenic mice in which Pet-1 is genetically ablated (Pet-1(-/-)) show a dramatic reduction (∼80%) in forebrain 5-HT levels, yet no investigations have been carried out to assess the impact of such severe 5-HT depletion on the function of target cortical neurons. Using whole cell patch-clamp methods, two-dimensional (2D) multielectrode arrays (MEAs), 3D morphological neuronal reconstructions, and animal behavior, we investigated the impact of 5-HT depletion on cortical cell-intrinsic and network excitability. We found significant changes in several parameters of cell-intrinsic excitability in cortical pyramidal cells (PCs) as well as an increase in spontaneous synaptic excitation through 5-HT3 receptors. These changes are associated with increased local network excitability and oscillatory activity in a 5-HT2 receptor-dependent manner, consistent with previously reported hypersensitivity of cortical 5-HT2 receptors. PC morphology was also altered, with a significant reduction in dendritic complexity that may possibly act as a compensatory mechanism for increased excitability. Consistent with this interpretation, when we carried out experiments with convulsant-induced seizures to asses cortical excitability in vivo, we observed no significant differences in seizure parameters between wild-type and Pet-1(-/-) mice. Moreover, MEA recordings of propagating field potentials showed diminished propagation of activity across the cortical sheath. Together these findings reveal novel functional changes in neuronal and cortical excitability in mice lacking Pet-1.
Collapse
Affiliation(s)
- Pavel A Puzerey
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Nathan X Kodama
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Roberto F Galán
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| |
Collapse
|
4
|
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.
Collapse
|
5
|
|
6
|
Heard K, Krier S, Zahniser NR. Administration of ziprasidone for 10 days increases cocaine toxicity in mice. Hum Exp Toxicol 2008; 27:499-503. [PMID: 18784203 DOI: 10.1177/0960327108095471] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Long-term treatment with antipsychotic medications alters the regional density of several of the neurotransmitter receptors that mediate cocaine toxicity. However, the effect of either up- or down-regulation of the neurotransmitter receptors on cocaine toxicity is unknown. In this study, we determined if subacute administration of the atypical antipsychotic ziprasidone altered the toxic effects of cocaine in mice. Ziprasidone (4 mg/kg) or placebo was administered to the first two groups of CF-1 mice for 10 days and, then on day 10, an estimated LD50 dose of cocaine (102 mg/kg) was given to these mice. In a third group, in order to produce a ziprasidone withdrawal state, we administered ziprasidone for 10 days, followed by no treatment for 2 days before cocaine administration. There was no significant difference among the three groups in overall survival: 63% in the treatment group, 60% in the withdrawal group, and 80% in the placebo group. Survival time was significantly shorter for the withdrawal group than for the control group. Our study may have been limited by lower than expected serum ziprasidone concentrations and lower than expected lethality from cocaine. However, our findings suggest that administration of an atypical antipsychotic for 10 days may increase the toxic effects of cocaine.
Collapse
Affiliation(s)
- K Heard
- Department of Surgery, Division of Emergency Medicine, University of Colorado School of Medicine, Denver, CO, USA.
| | | | | |
Collapse
|
7
|
Abstract
In recent years, there has been increasing evidence that serotonergic neurotransmission modulates a wide variety of experimentally induced seizures. Generally, agents that elevate extracellular serotonin (5-HT) levels, such as 5-hydroxytryptophan and serotonin reuptake blockers, inhibit both focal and generalized seizures, although exceptions have been described, too. Conversely, depletion of brain 5-HT lowers the threshold to audiogenically, chemically and electrically evoked convulsions. Furthermore, it has been shown that several anti-epileptic drugs increase endogenous extracellular 5-HT concentration. 5-HT receptors are expressed in almost all networks involved in epilepsies. Currently, the role of at least 5-HT(1A), 5-HT(2C), 5-HT(3) and 5-HT(7) receptor subtypes in epileptogenesis and/or propagation has been described. Mutant mice lacking 5-HT(1A) or 5-HT(2C) receptors show increased seizure activity and/or lower threshold. In general, hyperpolarization of glutamatergic neurons by 5-HT(1A) receptors and depolarization of GABAergic neurons by 5-HT(2C) receptors as well as antagonists of 5-HT(3) and 5-HT(7) receptors decrease the excitability in most, but not all, networks involved in epilepsies. Imaging data and analysis of resected tissue of epileptic patients, and studies in animal models all provide evidence that endogenous 5-HT, the activity of its receptors, and pharmaceuticals with serotonin agonist and/or antagonist properties play a significant role in the pathogenesis of epilepsies.
Collapse
Affiliation(s)
- Gyorgy Bagdy
- Laboratory of Neurochemistry and Experimental Medicine, National Institute of Psychiatry and Neurology, Budapest, Hungary.
| | | | | | | |
Collapse
|
8
|
Morita K, Hamamoto M, Arai S, Kitayama S, Irifune M, Kawahara M, Kihira K, Dohi T. Inhibition of serotonin transporters by cocaine and meprylcaine through 5-TH2C receptor stimulation facilitates their seizure activities. Brain Res 2006; 1057:153-60. [PMID: 16125150 DOI: 10.1016/j.brainres.2005.07.049] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2005] [Revised: 07/22/2005] [Accepted: 07/25/2005] [Indexed: 11/30/2022]
Abstract
The present study examined whether the inhibition of serotonin transporters (SERT) contributes to cocaine- and other local anesthetics-induced convulsions, and which subtypes of 5-HT receptor are involved in the convulsions. For this purpose, cocaine, meprylcaine and lidocaine, all of which have different effects on SERT, were used as convulsants and the effects of serotonin reuptake inhibitors (SSRIs), specific agonists and antagonists for 5-HT receptor subtypes were evaluated in mice. Administration of SSRI, zimelidine, citalopram and fluoxetine, 5-HT(2A,2C) receptor agonist, R(-)-DOI and the 5-HT2C receptor agonists, mCPP, and MK212 resulted in a marked increase in incidence of convulsions and a reduction in the threshold of lidocaine-induced convulsions, while the 5-HT2B receptor agonist, BW723C86, had little influence. On the other hand, SSRI did not affect the measured parameters in meprylcaine- and cocaine-induced convulsions. R(-)-DOI, mCPP, and MK212 reduced the threshold of meprylcaine or cocaine with less extent than the reduction of lidocaine threshold. Incidence of cocaine- and meprylcaine-induced convulsions was significantly reduced by 5-HT(2A,2B,2C) antagonist, LY-53857, and 5-HT2C antagonist, RS 102221. The threshold of cocaine and meprylcaine was significantly increased by both antagonists. 5-HT2A antagonists MDL 11,939 and ketanserin, and 5-HT2B antagonist SB 204741 except at high doses had little effect on cocaine- and meprylcaine-induced convulsions. None of these antagonists altered the parameters of lidocaine-induced convulsions. Pretreatment with fluoxetine but not citalopram increased the plasma concentration of lidocaine. These results suggest that the increase of serotonergic neuronal activity through 5-HT2C receptor stimulation was responsible for increased activity of local anesthetics-induced convulsions and support the involvement of this mechanism in cocaine- and meprylcaine- but not in lidocaine-induced convulsions through their direct inhibitory action on central SERT.
Collapse
Affiliation(s)
- Katsuya Morita
- Department of Dental Pharmacology, Division of Integrated Medical Science, Hiroshima University Graduate School of Biomedical Sciences, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553, Japan
| | | | | | | | | | | | | | | |
Collapse
|
9
|
Mendes de Freitas R, Aguiar LMV, Vasconcelos SMM, Sousa FCF, Viana GSB, Fonteles MMF. Modifications in muscarinic, dopaminergic and serotonergic receptors concentrations in the hippocampus and striatum of epileptic rats. Life Sci 2005; 78:253-8. [PMID: 16137708 DOI: 10.1016/j.lfs.2005.04.045] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2004] [Accepted: 04/19/2005] [Indexed: 11/27/2022]
Abstract
The present study was undertaken in order to investigate the muscarinic (M(1)), dopaminergic (D(1) and D(2)) and serotonergic (5-HT(2)) receptors densities in hippocampus and striatum of Wistar rats after status epilepticus (SE) induced by pilocarpine. The control group was treated with 0.9% saline. An other group of rats received pilocarpine (400 mg/kg, s.c.) and both groups were sacrificed 1 h after treatment. The results have shown that pilocarpine administration and resulting SE produced a downregulation of M(1) receptor in hippocampus (41%) and striatum (51%) and an increase in the dissociation constant (K(d)) values in striatum (42%) alone. In both areas the 5-HT(2) receptor density remained unaltered, but a reduction (50%) and an increase (15%) in the K(d) values were detected in striatum and hippocampus, respectively. D(1) and D(2) receptor densities in hippocampus and striatum remained unaltered meanwhile K(d) values for D(1) receptor declined significantly, 33% in hippocampus and 26% in striatum. Similarly, K(d) values for D(2) decreased 55% in hippocampus and 52% in striatum. From the preceding results, it is clear that there is a possible relation between alterations in muscarinic receptor density and others systems studied as well as they suggest that changes in dissociation constant can be responsible for the establishment of pilocarpine-induced SE by altering the affinity of neurotransmitters such as acetylcholine, dopamine and serotonine.
Collapse
Affiliation(s)
- Rivelilson Mendes de Freitas
- Department of Physiology and Pharmacology, Laboratory of Neuropharmacology, School of Medicine, Federal University of Ceará, Rua Cel. Nunes de Melo 1127, Fortaleza 60431-970, CE, Brazil.
| | | | | | | | | | | |
Collapse
|
10
|
Macêdo DS, Santos RS, Belchior LD, Neto MA, Vasconcelos SMM, Lima VTM, Fonteles MMF, Viana GSB, de Sousa FCF. Effect of anxiolytic, antidepressant, and antipsychotic drugs on cocaine-induced seizures and mortality. Epilepsy Behav 2004; 5:852-6. [PMID: 15582832 DOI: 10.1016/j.yebeh.2004.07.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2004] [Revised: 06/15/2004] [Accepted: 07/27/2004] [Indexed: 10/26/2022]
Abstract
Cocaine abuse may lead to overdose (related to seizures and/or status epilepticus) and to diseases (schizophrenia, depression, and anxiety). This work was designed to study the influence of drugs used to treat psychopathologies associated with cocaine abuse on cocaine-induced seizures and mortality in mice. Fluoxetine (10, 20, 40 mg/kg), imipramine and buspirone (5, 10 mg/kg), pimozide (10, 20 mg/kg), lithium (56.3, 112.5 mg/kg), and naltrexone (25, 50 mg/kg) were administered intraperitoneally, 30 minutes prior to cocaine (90 mg/kg, ip). The animals were observed (30 minutes) to determine: latency to first seizure, number of seizures, and number of deaths after cocaine overdose. Fluoxetine, imipramine, buspirone, and pimozide had pro- or anticonvulsant effects depending on the dose. Smaller doses protected and higher doses increased cocaine-induced seizures and/or mortality. Naltrexone worsened and lithium protected against seizures. Thus, these results suggest that caution should be taken in the selection of pharmacotherapy and dosages for patients with cocaine addiction because of the possibility of potentiating cocaine toxicity.
Collapse
|
11
|
Freitas RM, Vasconcelos SMM, Souza FCF, Viana GSB, Fonteles MMF. Monoamine levels after pilocarpine-induced status epilepticus in hippocampus and frontal cortex of Wistar rats. Neurosci Lett 2004; 370:196-200. [PMID: 15488322 DOI: 10.1016/j.neulet.2004.08.024] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2004] [Revised: 08/09/2004] [Accepted: 08/11/2004] [Indexed: 11/20/2022]
Abstract
Pilocarpine-induced status epilepticus (SE) is an useful model to study the involvement of neurotransmitter systems as epileptogenesis modulators. Some researches have shown that pharmacological manipulations in dopaminergic, serotonergic, and noradrenergic systems alter the occurrence of pilocarpine-induced SE. The control group was treated with 0.9% saline (control group, s.c.). Another group of rats received pilocarpine (400mg/kg, s.c.) and both groups were sacrificed 24 h after the treatment. This work was performed to determine the alterations in monoamine levels (dopamine (DA), serotonin (5-HT) and norepinephrine (NE)) and their metabolites (3,4-hydroxyphenylacetic acid (DOPAC), homovanilic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA)) after pilocarpine-induced SE in hippocampus and frontal cortex of adult rats. The monoamines and their metabolites were determined by reverse-phase high-performance liquid chromatography with electrochemical detection. DA and 5-HIAA concentrations were not altered in the hippocampus of the pilocarpine group, but in the same group the 5-HT (160%), DOPAC (316%) and HVA (21%) levels increased, whereas, the NE (47%) content declined. For the frontal cortex determinations, there was an increase of 20 and 72% in DA and DOPAC levels, respectively, and a decrease in NE (32%), 5-HT (33%) and 5-HIAA (19%) concentrations, but HVA content remained unaltered. These results indicate that pilocarpine-induced SE can alter monoamine levels in different ways depending on the brain area studied, suggesting that different mechanisms are involved.
Collapse
Affiliation(s)
- R M Freitas
- Laboratory of Neuropharmacology, Department of Physiology and Pharmacology, School of Medicine, Federal University of Ceará, Rua Cel. Nunes de Melo 1127, Fortaleza 60431-970, CE, Brazil.
| | | | | | | | | |
Collapse
|
12
|
Zienowicz M, Wisłowska A, Lehner M, Taracha E, Skórzewska A, Maciejak P, Płaźnik A. The effect of fluoxetine in a model of chemically induced seizures--behavioral and immunocytochemical study. Neurosci Lett 2004; 373:226-31. [PMID: 15619548 DOI: 10.1016/j.neulet.2004.10.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2004] [Revised: 10/01/2004] [Accepted: 10/05/2004] [Indexed: 11/16/2022]
Abstract
The aim of this study was to examine the effects of acute fluoxetine treatment on pentylenetetrazol-induced convulsions in order to shape a model of seizures associated with treatment with antidepressants in rats. Moreover, the putative role of the hippocampal formation in this respect was investigated with the help of c-fos immuncytochemistry to mark local neuronal activity. It was found that fluoxetine (10.0 mg/kg, i.p.) enhanced the proconvulsive effect of pentylenetetrazol (50.0 mg/kg, i.p.), and simultaneously inhibited pentylenetetrazol-stimulated c-Fos expression in some areas of the hippocampus. Fluoxetine pretreatment did not alter pentylenetetrazol brain concentration indicating that this phenomenon was not related to the pharmacokinetic interaction. It is suggested that inhibition by fluoxetine of some neuronal populations contributing to the local feedback mechanism controlling excessive epileptiform discharges within the hippocampus might lead to an increase in epileptic activity. The reported in the present paper fluoxetine versus pentylenetetrazol interaction may, therefore, serve as a model of seizures associated with treatment with antidepressants.
Collapse
Affiliation(s)
- Małgorzata Zienowicz
- Department of Experimental and Clinical Pharmacology, Warsaw Medical University, 26/28 Krakowskie Przedmiescie Street, 00-927 Warsaw, Poland
| | | | | | | | | | | | | |
Collapse
|