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Nawata Y, Nishioku T, Yamamoto T, Yamaguchi T. 3,4-Methylenedioxymethamphetamine (MDMA) impairs cognitive function during withdrawal via activation of the arachidonic acid cascade in the hippocampus. Drug Alcohol Depend 2024; 257:111139. [PMID: 38430788 DOI: 10.1016/j.drugalcdep.2024.111139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 02/14/2024] [Accepted: 02/19/2024] [Indexed: 03/05/2024]
Abstract
BACKGROUND The recreational drug ±3,4-methylenedioxymethamphetamine (MDMA; also known as "ecstasy") has unusual subjective prosocial and empathogenic effects, and has exhibited potential as an adjunct to psychotherapy in recent years. However, there has been some concern regarding possible neuropsychiatric symptoms, such as cognitive impairment and dependence, emerging after abstinence. Therefore, this study aimed to evaluate the mechanism underlying cognitive impairment during MDMA withdrawal. To achieve this, we focused on the arachidonic acid cascade, which is related to addiction to some abusive drugs. METHODS A novel object recognition task was used to investigate cognitive function in mice. Furthermore, we quantified prostaglandin E2 during MDMA withdrawal. RESULTS The recognition index significantly decreased during withdrawal after repeated administration of MDMA (10mg/kg, i.p., once daily for 7 days), but not following co-administration of diclofenac (10mg/kg, i.p.), a cyclooxygenase inhibitor. On day 1, following repeated MDMA treatment, prostaglandin E2 content significantly increased in the hippocampus but not in the prefrontal cortex and striatum. CONCLUSIONS Our findings indicate that activation of the arachidonic acid cascade at least in the hippocampus is likely involved in the development of recognition memory impairment during MDMA withdrawal. Therefore, co-use of cyclooxygenase inhibitors with MDMA may reduce concerns regarding MDMA-induced impairment of recognition memory.
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Affiliation(s)
- Yoko Nawata
- Department of Pharmacology, Faculty of Pharmaceutical Science, Nagasaki International University, 2825-7 Huis Ten Bosch, Sasebo, Nagasaki 859-3298, Japan
| | - Tsuyoshi Nishioku
- Department of Pharmacology, Faculty of Pharmaceutical Science, Nagasaki International University, 2825-7 Huis Ten Bosch, Sasebo, Nagasaki 859-3298, Japan
| | - Tsuneyuki Yamamoto
- Department of Pharmacotherapeutics and Neuropsychopharmacology, Faculty of Pharmaceutical Science, Nagasaki International University, 2825-7 Huis Ten Bosch, Sasebo, Nagasaki 859-3298, Japan
| | - Taku Yamaguchi
- Department of Pharmacotherapeutics and Neuropsychopharmacology, Faculty of Pharmaceutical Science, Nagasaki International University, 2825-7 Huis Ten Bosch, Sasebo, Nagasaki 859-3298, Japan.
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2
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Khoram-Abadi KM, Basiri M, Nemati M, Nozari M. Agmatine ameliorates valproic acid-induced depletion of parvalbumin-positive neuron. Int J Dev Neurosci 2024; 84:134-142. [PMID: 38304999 DOI: 10.1002/jdn.10314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 12/08/2023] [Accepted: 12/13/2023] [Indexed: 02/03/2024] Open
Abstract
Autism spectrum disorder (ASD) is a widespread neurodevelopmental disorder with unknown etiology. Dysfunction of several brain areas including the prefrontal cortex (PFC), hippocampus, and cerebellum is involved in cognitive and behavioral deficits associated with ASD. Several studies have reported a reduction in the number of parvalbumin-immunoreactive (PV+) neurons in brain areas of ASD patients and animal models such as a shank mutant mouse model and rodents receiving fetal valproic acid (VPA) administration. Developing therapeutic interventions that restore PV interneurons can be the future therapeutic approach to ASD. The present study examined the possible effect of agmatine (AG), an endogenous NMDA antagonist, on the number of PV+ neurons in a VPA animal model of autism. The therapeutic effects of AG in ameliorating ASD-like behaviors were previously reported in VPA rats. AG was gavaged at dosages of 0.001, 0.01, and 0.1 mg/kg from gestational day (GD) 6.5 to 18.5, and the number of PV interneurons was analyzed by immunohistochemistry in the 1-month-old rats. Prenatal VPA (GD 12.5) or AG led to a decrease of PV neurons in the PFC, Cornu ammonia (CA1), and molecular layers (MLs) of the cerebellum. However, exposure to AG restored the PV population induced by VPA. AG may modify underlying neuronal mechanisms resulting in the increased survival or restoration of the PV population.
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Affiliation(s)
- Khadijeh Mirzaee Khoram-Abadi
- Student Research Committee, Kerman University of Medical Sciences, Kerman, Iran
- Department of Anatomical Sciences, Afzalipour School of Medicine, Kerman University of Medical Sciences, Kerman, Iran
| | - Mohsen Basiri
- Department of Anatomical Sciences, Afzalipour School of Medicine, Kerman University of Medical Sciences, Kerman, Iran
| | - Mozhdeh Nemati
- Neuroscience Research Center, Institute of Neuropharmacology, Department of Physiology and Pharmacology, Afzalipour School of Medicine, Kerman University of Medical Sciences, Kerman, Iran
| | - Masoumeh Nozari
- Neuroscience Research Center, Institute of Neuropharmacology, Department of Physiology and Pharmacology, Afzalipour School of Medicine, Kerman University of Medical Sciences, Kerman, Iran
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3
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Li W, Wu J, Zeng Y, Zheng W. Neuroinflammation in epileptogenesis: from pathophysiology to therapeutic strategies. Front Immunol 2023; 14:1269241. [PMID: 38187384 PMCID: PMC10771847 DOI: 10.3389/fimmu.2023.1269241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Accepted: 12/07/2023] [Indexed: 01/09/2024] Open
Abstract
Epilepsy is a group of enduring neurological disorder characterized by spontaneous and recurrent seizures with heterogeneous etiology, clinical expression, severity, and prognosis. Growing body of research investigates that epileptic seizures are originated from neuronal synchronized and excessive electrical activity. However, the underlying molecular mechanisms of epileptogenesis have not yet been fully elucidated and 30% of epileptic patients still are resistant to the currently available pharmacological treatments with recurrent seizures throughout life. Over the past two decades years accumulated evidences provide strong support to the hypothesis that neuroinflammation, including microglia and astrocytes activation, a cascade of inflammatory mediator releasing, and peripheral immune cells infiltration from blood into brain, is associated with epileptogenesis. Meanwhile, an increasing body of preclinical researches reveal that the anti-inflammatory therapeutics targeting crucial inflammatory components are effective and promising in the treatment of epilepsy. The aim of the present study is to highlight the current understanding of the potential neuroinflammatory mechanisms in epileptogenesis and the potential therapeutic targets against epileptic seizures.
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Chen Y, Nagib MM, Yasmen N, Sluter MN, Littlejohn TL, Yu Y, Jiang J. Neuroinflammatory mediators in acquired epilepsy: an update. Inflamm Res 2023; 72:683-701. [PMID: 36745211 DOI: 10.1007/s00011-023-01700-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 01/23/2023] [Accepted: 01/25/2023] [Indexed: 02/07/2023] Open
Abstract
Epilepsy is a group of chronic neurological disorders that have diverse etiologies but are commonly characterized by spontaneous seizures and behavioral comorbidities. Although the mechanisms underlying the epileptic seizures mostly remain poorly understood and the causes often can be idiopathic, a considerable portion of cases are known as acquired epilepsy. This form of epilepsy is typically associated with prior neurological insults, which lead to the initiation and progression of epileptogenesis, eventually resulting in unprovoked seizures. A convergence of evidence in the past two decades suggests that inflammation within the brain may be a major contributing factor to acquired epileptogenesis. As evidenced in mounting preclinical and human studies, neuroinflammatory processes, such as activation and proliferation of microglia and astrocytes, elevated production of pro-inflammatory cytokines and chemokines, blood-brain barrier breakdown, and upregulation of inflammatory signaling pathways, are commonly observed after seizure-precipitating events. An increased knowledge of these neuroinflammatory processes in the epileptic brain has led to a growing list of inflammatory mediators that can be leveraged as potential targets for new therapies of epilepsy and/or biomarkers that may provide valued information for the diagnosis and prognosis of the otherwise unpredictable seizures. In this review, we mainly focus on the most recent progress in understanding the roles of these inflammatory molecules in acquired epilepsy and highlight the emerging evidence supporting their candidacy as novel molecular targets for new pharmacotherapies of acquired epilepsy and the associated behavioral deficits.
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Affiliation(s)
- Yu Chen
- Department of Pharmaceutical Sciences, College of Pharmacy, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - Marwa M Nagib
- Department of Pharmaceutical Sciences, College of Pharmacy, The University of Tennessee Health Science Center, Memphis, TN, USA.,Department of Pharmacology and Toxicology, Faculty of Pharmacy, Misr International University, Cairo, Egypt
| | - Nelufar Yasmen
- Department of Pharmaceutical Sciences, College of Pharmacy, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - Madison N Sluter
- Department of Pharmaceutical Sciences, College of Pharmacy, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - Taylor L Littlejohn
- Department of Pharmaceutical Sciences, College of Pharmacy, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - Ying Yu
- Department of Pharmaceutical Sciences, College of Pharmacy, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - Jianxiong Jiang
- Department of Pharmaceutical Sciences, College of Pharmacy, The University of Tennessee Health Science Center, Memphis, TN, USA.
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Kline HL, Yamamoto BK. Alcohol reinstatement after prolonged abstinence from alcohol drinking by female adolescent rats: Roles of cyclooxygenase-2 and the prostaglandin E 2 receptor 1. Drug Alcohol Depend 2022; 236:109491. [PMID: 35537317 DOI: 10.1016/j.drugalcdep.2022.109491] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/12/2022] [Accepted: 05/01/2022] [Indexed: 12/29/2022]
Abstract
BACKGROUND Adolescent alcohol misuse is a global problem that can significantly increase the reinstatement of alcohol drinking during re-exposure after abstinence, but the mechanism that causes this increase is unknown. Female adolescents are an understudied population but they are particularly vulnerable to adolescent-onset alcohol abuse. We aimed to determine how adolescent-onset alcohol drinking affects pro-inflammatory mediators endothelin-1 (ET-1), cyclooxygenase-2 (COX-2), and prostaglandin E2 (PGE2) in the brain and the role of COX-2 and PGE2 in EtOH reinstatement in adolescent females. METHODS Adolescent female rats were exposed to a 2-bottle choice paradigm of water vs 5% ethanol (EtOH) every other day over a 21 day period. ET-1 and COX-2 proteins were measured in the dorsal striatum (DS) after a 4 week abstinence from EtOH drinking. The COX-2 inhibitor nimesulide was then administered during abstinence prior to an EtOH reinstatement or sucrose preference or to measure PGE2 content. The PGE2 receptor 1 (EP1) antagonist SC-51089 was then administered prior to EtOH reinstatement during which EtOH intake was measured. RESULTS EtOH drinking significantly increased ET-1 by 33.8 ± 8.9% and COX-2 by 71.4 ± 24.3% in the DS. Treatment with nimesulide during abstinence attenuated EtOH intake during reinstatement after prolonged abstinence by 40.3 ± 12.4% compared to saline controls. Adolescent EtOH drinking and abstinence increased PGE2 150.5 ± 30.9% in the DS and nimesulide attenuated this increase. SC-51089 treatment during abstinence attenuated EtOH reinstatement by 48.1 ± 8.4% compared to DMSO controls. CONCLUSIONS These experiments identified a prostaglandin-mediated mechanism that offers a putative pharmacological target to attenuate EtOH reinstatement after adolescent-onset EtOH drinking.
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Affiliation(s)
- Hannah L Kline
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA; Medical Neuroscience Graduate Program, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Bryan K Yamamoto
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA; Stark Neuroscience Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA.
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6
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Sourbron J, Lagae L. Serotonin receptors in epilepsy: novel treatment targets? Epilepsia Open 2022; 7:231-246. [PMID: 35075810 PMCID: PMC9159250 DOI: 10.1002/epi4.12580] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 01/08/2022] [Accepted: 01/20/2022] [Indexed: 11/24/2022] Open
Abstract
Despite the availability of over 30 antiseizure medications (ASMs), there is no “one size fits it all,” so there is a continuing search for novel ASMs. There are divergent data demonstrating that modulation of distinct serotonin (5‐hydroxytryptamine, 5‐HT) receptors subtypes could be beneficial in the treatment of epilepsy and its comorbidities, whereas only a few ASM, such as fenfluramine (FA), act via 5‐HT. There are 14 different 5‐HT receptor subtypes, and most epilepsy studies focus on one or a few of these subtypes, using different animal models and different ligands. We reviewed the available evidence of each 5‐HT receptor subtype using MEDLINE up to July 2021. Our search included medical subject heading (MeSH) and free terms of each “5‐HT subtype” separately and its relation to “epilepsy or seizures.” Most research underlines the antiseizure activity of 5‐HT1A,1D,2A,2C,3 agonism and 5‐HT6 antagonism. Consistently, FA, which has recently been approved for the treatment of seizures in Dravet syndrome, is an agonist of 5‐HT1D,2A,2C receptors. Even though each study focused on a distinct seizure/epilepsy type and generalization of different findings could lead to false interpretations, we believe that the available preclinical and clinical studies emphasize the role of serotonergic modulation, especially stimulation, as a promising avenue in epilepsy treatment.
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Affiliation(s)
- Jo Sourbron
- Department of Development and Regeneration, Section Pediatric Neurology, University Hospital KU Leuven, Leuven, Belgium.,Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Lieven Lagae
- Department of Development and Regeneration, Section Pediatric Neurology, University Hospital KU Leuven, Leuven, Belgium
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Li IH, Shih JH, Yeh TY, Lin HC, Chen MH, Huang YS. Lysosomal Dysfunction and Autophagy Blockade Contribute to MDMA-Induced Neurotoxicity in SH-SY5Y Neuroblastoma Cells. Chem Res Toxicol 2020; 33:903-914. [PMID: 32186374 DOI: 10.1021/acs.chemrestox.9b00437] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Methylenedioxymethamphetamine (MDMA) is a psychostimulant with high abuse potential and severe neurotoxicity. According to our previous study, MDMA promotes autophagosome accumulation and contributes to cell death in cultured cortical and serotonergic neurons. However, the detailed mechanism underlying autophagy dysfunction remains unclear. Lysosomes play an important role in autophagic degradation. The present study aimed to examine the role of lysosomal function in autophagic flux in neuronal cultures exposed to MDMA. We showed that MDMA induced enlarged vesicles that accumulate in SH-SY5Y neuroblastoma cells. In addition, we demonstrated that MDMA stimulated dynamin-dependent but clathrin-independent endocytosis, which might contribute to vacuole expansion. Morphological and Western blot analyses revealed that MDMA induced lysosomal swelling, whereas the activity of the lysosomal hydrolytic enzymes cathepsin B and cathepsin D was decreased in SH-SY5Y and cultured cortical neurons, which might lead to autophagosome accumulation and autophagic degradation blockage. Intriguingly, inactivation of cathepsins B and D led to cell death and autophagy-lysosomal dysregulation, which mimicked MDMA-induced neurotoxicity. Consequently, impairment of lysosomal proteolysis and blockage of autophagy degradation contributed to MDMA-induced neurotoxicity in neuronal cultures.
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Affiliation(s)
- I-Hsun Li
- Department of Pharmacy Practice, Tri-Service General Hospital, Taipei 114, Taiwan.,School of Pharmacy, National Defense Medical Center, Taipei 114, Taiwan
| | - Jui-Hu Shih
- Department of Pharmacy Practice, Tri-Service General Hospital, Taipei 114, Taiwan.,School of Pharmacy, National Defense Medical Center, Taipei 114, Taiwan
| | - Ting-Yin Yeh
- Department of Biology and Anatomy, National Defense Medical Center, Taipei 114, Taiwan
| | - Hung-Che Lin
- Department of Otolaryngology-Head and Neck Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan
| | - Ming-Hua Chen
- Division of Neurology, Department of Medicine, Armed Forces Taoyuan General Hospital, Taoyuan 325, Taiwan.,Department of Neurology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Yuahn-Sieh Huang
- Department of Biology and Anatomy, National Defense Medical Center, Taipei 114, Taiwan
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8
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Mitchell CM, El Jordi O, Yamamoto BK. Inflammatory mechanisms of abused drugs. ROLE OF INFLAMMATION IN ENVIRONMENTAL NEUROTOXICITY 2019. [DOI: 10.1016/bs.ant.2018.10.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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9
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Radhakrishnan R, Nabulsi N, Gaiser E, Gallezot JD, Henry S, Planeta B, Lin SF, Ropchan J, Williams W, Morris E, D'Souza DC, Huang Y, Carson RE, Matuskey D. Age-Related Change in 5-HT 6 Receptor Availability in Healthy Male Volunteers Measured with 11C-GSK215083 PET. J Nucl Med 2018; 59:1445-1450. [PMID: 29626125 DOI: 10.2967/jnumed.117.206516] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 03/21/2018] [Indexed: 12/23/2022] Open
Abstract
Serotonin receptor 6 (5-hydroxytrypamine-6, or 5-HT6) is a potential therapeutic target given its distribution in brain regions that are important in depression, anxiety, and cognition. This study sought to investigate the effects of age on 5-HT6 receptor availability using 11C-GSK215083, a PET ligand with affinity for 5-HT6 in the striatum and 5-HT2A in the cortex. Methods: Twenty-eight healthy male volunteers (age range, 23-52 y) were scanned with 11C-GSK215083 PET. Time-activity curves in regions of interest were fitted using a multilinear analysis method. Nondisplaceable binding potential (BPND) was calculated using the cerebellum as the reference region and corrected for partial-volume effects. Results: In 5-HT6-rich areas, regional 11C-GSK215083 showed a negative correlation between BPND and age in the caudate (r = -0.41, P = 0.03) (14% change per decade) and putamen (r = -0.30, P = 0.04) (11% change per decade) but not in the ventral striatum or pallidum. A negative correlation with age was also seen in cortical regions (r = -0.41, P = 0.03) (7% change per decade), consistent with the literature on 5-HT2A availability. Conclusion: To our knowledge, this was the first in vivo study on humans to examine the effect of age on 5-HT6 receptor availability. The study demonstrated a significant age-related decline in 5-HT6 availability (BPND) in the caudate and putamen.
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Affiliation(s)
- Rajiv Radhakrishnan
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut
| | - Nabeel Nabulsi
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut; and
| | - Edward Gaiser
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut
| | - Jean-Dominique Gallezot
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut; and
| | - Shannan Henry
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut; and
| | - Beata Planeta
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut; and
| | - Shu-Fei Lin
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut; and
| | - Jim Ropchan
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut; and
| | - Wendol Williams
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut
| | - Evan Morris
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut; and.,Department of Biomedical Engineering, Yale University, New Haven, Connecticut
| | - Deepak Cyril D'Souza
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut
| | - Yiyun Huang
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut; and
| | - Richard E Carson
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut; and.,Department of Biomedical Engineering, Yale University, New Haven, Connecticut
| | - David Matuskey
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut .,Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut; and
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Huff CL, Morano RL, Herman JP, Yamamoto BK, Gudelsky GA. MDMA decreases glutamic acid decarboxylase (GAD) 67-immunoreactive neurons in the hippocampus and increases seizure susceptibility: Role for glutamate. Neurotoxicology 2016; 57:282-290. [PMID: 27773601 DOI: 10.1016/j.neuro.2016.10.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 10/17/2016] [Accepted: 10/18/2016] [Indexed: 01/15/2023]
Abstract
3,4-Methylenedioxy-methamphetamine (MDMA) is a unique psychostimulant that continues to be a popular drug of abuse. It has been well documented that MDMA reduces markers of 5-HT axon terminals in rodents, as well as humans. A loss of parvalbumin-immunoreactive (IR) interneurons in the hippocampus following MDMA treatment has only been documented recently. In the present study, we tested the hypothesis that MDMA reduces glutamic acid decarboxylase (GAD) 67-IR, another biochemical marker of GABA neurons, in the hippocampus and that this reduction in GAD67-IR neurons and an accompanying increase in seizure susceptibility involve glutamate receptor activation. Repeated exposure to MDMA (3×10mg/kg, ip) resulted in a reduction of 37-58% of GAD67-IR cells in the dentate gyrus (DG), CA1, and CA3 regions, as well as an increased susceptibility to kainic acid-induced seizures, both of which persisted for at least 30days following MDMA treatment. Administration of the NMDA antagonist MK-801 or the glutamate transporter type 1 (GLT-1) inducer ceftriaxone prevented both the MDMA-induced loss of GAD67-IR neurons and the increased vulnerability to kainic acid-induced seizures. The MDMA-induced increase in the extracellular concentration of glutamate in the hippocampus was significantly diminished in rats treated with ceftriaxone, thereby implicating a glutamatergic mechanism in the neuroprotective effects of ceftriaxone. In summary, the present findings support a role for increased extracellular glutamate and NMDA receptor activation in the MDMA-induced loss of hippocampal GAD67-IR neurons and the subsequent increased susceptibility to evoked seizures.
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Affiliation(s)
- Courtney L Huff
- Division of Pharmaceutical Sciences, University of Cincinnati-James Winkle College of Pharmacy, Cincinnati, OH 45267, United States
| | - Rachel L Morano
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati-College of Medicine, Cincinnati, OH, 45219, United States
| | - James P Herman
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati-College of Medicine, Cincinnati, OH, 45219, United States
| | - Bryan K Yamamoto
- Department of Pharmacology and Toxicology, Indiana University-School of Medicine, Indianapolis, IN 46202, United States
| | - Gary A Gudelsky
- Division of Pharmaceutical Sciences, University of Cincinnati-James Winkle College of Pharmacy, Cincinnati, OH 45267, United States.
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