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Park JH, Hwang Y, Nguyen YND, Kim HC, Shin EJ. Ramelteon attenuates hippocampal neuronal loss and memory impairment following kainate-induced seizures. J Pineal Res 2024; 76:e12921. [PMID: 37846173 DOI: 10.1111/jpi.12921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 09/18/2023] [Accepted: 09/26/2023] [Indexed: 10/18/2023]
Abstract
Evidence suggests that the neuroprotective effects of melatonin involve both receptor-dependent and -independent actions. However, little is known about the effects of melatonin receptor activation on the kainate (KA) neurotoxicity. This study examined the effects of repeated post-KA treatment with ramelteon, a selective agonist of melatonin receptors, on neuronal loss, cognitive impairment, and depression-like behaviors following KA-induced seizures. The expression of melatonin receptors decreased in neurons, whereas it was induced in astrocytes 3 and 7 days after seizures elicited by KA (0.12 μg/μL) in the hippocampus of mice. Ramelteon (3 or 10 mg/kg, i.p.) and melatonin (10 mg/kg, i.p.) mitigated KA-induced oxidative stress and impairment of glutathione homeostasis and promoted the nuclear translocation and DNA binding activity of Nrf2 in the hippocampus after KA treatment. Ramelteon and melatonin also attenuated microglial activation but did not significantly affect astroglial activation induced by KA, despite the astroglial induction of melatonin receptors after KA treatment. However, ramelteon attenuated KA-induced proinflammatory phenotypic changes in astrocytes. Considering the reciprocal regulation of astroglial and microglial activation, these results suggest ramelteon inhibits microglial activation by regulating astrocyte phenotypic changes. These effects were accompanied by the attenuation of the nuclear translocation and DNA binding activity of nuclear factor κB (NFκB) induced by KA. Consequently, ramelteon attenuated the KA-induced hippocampal neuronal loss, memory impairment, and depression-like behaviors; the effects were comparable to those of melatonin. These results suggest that ramelteon-mediated activation of melatonin receptors provides neuroprotection against KA-induced neurotoxicity in the mouse hippocampus by activating Nrf2 signaling to attenuate oxidative stress and restore glutathione homeostasis and by inhibiting NFκB signaling to attenuate neuroinflammatory changes.
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Affiliation(s)
- Jung Hoon Park
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chuncheon, Republic of Korea
| | - Yeonggwang Hwang
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chuncheon, Republic of Korea
| | - Yen Nhi Doan Nguyen
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chuncheon, Republic of Korea
| | - Hyoung-Chun Kim
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chuncheon, Republic of Korea
| | - Eun-Joo Shin
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chuncheon, Republic of Korea
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Hwang Y, Kim HC, Shin EJ. Repeated exposure to microcystin-leucine-arginine potentiates excitotoxicity induced by a low dose of kainate. Toxicology 2021; 460:152887. [PMID: 34352349 DOI: 10.1016/j.tox.2021.152887] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 07/15/2021] [Accepted: 07/30/2021] [Indexed: 02/08/2023]
Abstract
Microcystin-leucine-arginine (MLCR) is a cyanobacterial toxin, and has been demonstrated to cause neurotoxicity. In addition, MCLR has been identified as an inhibitor of protein phosphatase (PP)1 and PP2A, which are known to regulate the phosphorylation of various molecules related to synaptic excitability. Thus, in the present study, we examined whether MCLR exposure affects seizures induced by a low dose of kainic acid (KA; 0.05 μg, i.c.v.) administration. KA-induced seizure occurrence and seizure score significantly increased after repeated exposure to MCLR (2.5 or 5.0 μg/kg, i.p., once a day for 10 days), but not after acute MCLR exposure (2.5 or 5.0 μg/kg, i.p., 2 h and 30 min prior to KA administration), and hippocampal neuronal loss was consistently facilitated by repeated exposure to MCLR. In addition, repeated MCLR significantly elevated the membrane expression of kainate receptor GluK2 subunits, p-pan-protein kinase C (PKC), and p-extracellular signal-related kinase (ERK) at 1 h after KA. However, KA-induced membrane expression of Ca2+/calmodulin-dependent kinase II (CaMKII) was significantly reduced by repeated MCLR exposure. Consistent with the enhanced seizures and neurodegeneration, MCLR exposure significantly potentiated KA-induced oxidative stress and microglial activation, which was accompanied by increased expression of p-ERK and p-PKCδ in the hippocampus. The combined results suggest that repeated MCLR exposure potentiates KA-induced excitotoxicity in the hippocampus by increasing membrane GluK2 expression and enhancing oxidative stress and neuroinflammation through the modulation of p-CaMKII, p-PKC, and p-ERK.
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Affiliation(s)
- Yeonggwang Hwang
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Hyoung-Chun Kim
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chuncheon, 24341, Republic of Korea.
| | - Eun-Joo Shin
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chuncheon, 24341, Republic of Korea.
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3
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Demars F, Clark K, Wyeth MS, Abrams E, Buckmaster PS. A single subconvulsant dose of domoic acid at mid-gestation does not cause temporal lobe epilepsy in mice. Neurotoxicology 2018; 66:128-137. [PMID: 29625197 PMCID: PMC5940543 DOI: 10.1016/j.neuro.2018.04.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 03/28/2018] [Accepted: 04/02/2018] [Indexed: 11/19/2022]
Abstract
Harmful blooms of domoic acid (DA)-producing algae are a problem in oceans worldwide. DA is a potent glutamate receptor agonist that can cause status epilepticus and in survivors, temporal lobe epilepsy. In mice, one-time low-dose in utero exposure to DA was reported to cause hippocampal damage and epileptiform activity, leading to the hypothesis that unrecognized exposure to DA from contaminated seafood in pregnant women can damage the fetal hippocampus and initiate temporal lobe epileptogenesis. However, development of epilepsy (i.e., spontaneous recurrent seizures) has not been tested. In the present study, long-term seizure monitoring and histology was used to test for temporal lobe epilepsy following prenatal exposure to DA. In Experiment One, the previous study's in utero DA treatment protocol was replicated, including use of the CD-1 mouse strain. Afterward, mice were video-monitored for convulsive seizures from 2 to 6 months old. None of the CD-1 mice treated in utero with vehicle or DA was observed to experience spontaneous convulsive seizures. After seizure monitoring, mice were evaluated for pathological evidence of temporal lobe epilepsy. None of the mice treated in utero with DA displayed the hilar neuron loss that occurs in patients with temporal lobe epilepsy and in the mouse pilocarpine model of temporal lobe epilepsy. In Experiment Two, a higher dose of DA was administered to pregnant FVB mice. FVB mice were tested as a potentially more sensitive strain, because they have a lower seizure threshold, and some females spontaneously develop epilepsy. Female offspring were monitored with continuous video and telemetric bilateral hippocampal local field potential recording at 1-11 months old. A similar proportion of vehicle- and DA-treated female FVB mice spontaneously developed epilepsy, beginning in the fourth month of life. Average seizure frequency and duration were similar in both groups. Seizure frequency was lower than that of positive-control pilocarpine-treated mice, but seizure duration was similar. None of the mice treated in utero with vehicle or DA displayed hilar neuron loss or intense mossy fiber sprouting, a form of aberrant synaptic reorganization that develops in patients with temporal lobe epilepsy and in pilocarpine-treated mice. FVB mice that developed epilepsy (vehicle- and DA-treated) displayed mild mossy fiber sprouting. Results of this study suggest that a single subconvulsive dose of DA at mid-gestation does not cause temporal lobe epilepsy in mice.
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Affiliation(s)
- Fanny Demars
- Department of Comparative Medicine, School of Medicine, Stanford University, Stanford, CA, United States; VetAgro Sup, School of Veterinary Medicine, Lyon, France; Paris Descartes University, Paris, France
| | - Kristen Clark
- Department of Comparative Medicine, School of Medicine, Stanford University, Stanford, CA, United States; College of Veterinary Medicine, Oklahoma State University, Stillwater, OK, United States
| | - Megan S Wyeth
- Department of Comparative Medicine, School of Medicine, Stanford University, Stanford, CA, United States
| | - Emily Abrams
- Department of Comparative Medicine, School of Medicine, Stanford University, Stanford, CA, United States
| | - Paul S Buckmaster
- Department of Comparative Medicine, School of Medicine, Stanford University, Stanford, CA, United States; Department of Neurology & Neurological Sciences, School of Medicine, Stanford University, Stanford, CA, United States.
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Wang D, Zhao J, Li S, Shen G, Hu S. Quercetin attenuates domoic acid-induced cognitive deficits in mice. Nutr Neurosci 2016; 21:123-131. [PMID: 28277184 DOI: 10.1080/1028415x.2016.1231438] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Domoic acid (DA) is one of the best known marine toxins, causative of important neurotoxic alterations. DA effects are documented both in wildlife and experimental assays, showing that this toxin causes severe injuries principally in the hippocampal area. Accumulating evidence indicates that mitochondrial dysfunction and oxidative stress are involved in DA-induced cognitive functional impairment. Therefore, therapeutics targeted to improve mitochondrial function and increase oxidative stress defence could be beneficial. Quercetin, a bioflavanoid, has been reported to have potent neuroprotective effects and anti-oxidative ability, but its preventive effects on DA-induced mitochondrial dysfunction and cognitive impairment have not been well characterised. In this study, we evaluated the effects of quercetin on DA-induced cognitive deficits in mice and explored its potential mechanism. Our results showed that the oral administration of quercetin to DA-treated mice significantly improved their behavioural performance in a novel objective recognition task and a Morris water maze task. These improvements were mediated, at least in part, by a stimulation of PPARγ coactivator 1α-mediated mitochondrial biogenesis signalling and an amelioration of mitochondrial dysfunction. Moreover, quercetin activated nuclear factorerythroid-2-related factor-2 (Nrf2)-mediated phase II enzymes and decreased reactive oxygen species and protein carbonylation. Furthermore, the AMP-activated protein kinase (AMPK) activity significantly increased in the quercetin-treated group. Taken together, these findings suggest that a reduction in mitochondrial dysfunction through the increase of AMPK activity, coupled with an increase in Nrf2 pathway mediated oxidative defence, may be one of the mechanisms by which quercetin improves cognitive impairment induced by DA in mice.
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Affiliation(s)
- Dongmei Wang
- a Department of Pathogen Biology, Medical College , Henan University of Science and Technology , Luoyang , China
| | - Jianlong Zhao
- b Department of Pathology, Medical College , Henan University of Science and Technology , Luoyang , China
| | - Sanqiang Li
- c Department of Biochemistry and Molecular Biology, Medical College , Henan University of Science and Technology , Luoyang , China
| | - Guomin Shen
- c Department of Biochemistry and Molecular Biology, Medical College , Henan University of Science and Technology , Luoyang , China
| | - Shu Hu
- c Department of Biochemistry and Molecular Biology, Medical College , Henan University of Science and Technology , Luoyang , China
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5
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Kesić S, Spasić SZ. Application of Higuchi's fractal dimension from basic to clinical neurophysiology: A review. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2016; 133:55-70. [PMID: 27393800 DOI: 10.1016/j.cmpb.2016.05.014] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 03/24/2016] [Accepted: 05/27/2016] [Indexed: 06/06/2023]
Abstract
BACKGROUND AND OBJECTIVE For more than 20 years, Higuchi's fractal dimension (HFD), as a nonlinear method, has occupied an important place in the analysis of biological signals. The use of HFD has evolved from EEG and single neuron activity analysis to the most recent application in automated assessments of different clinical conditions. Our objective is to provide an updated review of the HFD method applied in basic and clinical neurophysiological research. METHODS This article summarizes and critically reviews a broad literature and major findings concerning the applications of HFD for measuring the complexity of neuronal activity during different neurophysiological conditions. The source of information used in this review comes from the PubMed, Scopus, Google Scholar and IEEE Xplore Digital Library databases. RESULTS The review process substantiated the significance, advantages and shortcomings of HFD application within all key areas of basic and clinical neurophysiology. Therefore, the paper discusses HFD application alone, combined with other linear or nonlinear measures, or as a part of automated methods for analyzing neurophysiological signals. CONCLUSIONS The speed, accuracy and cost of applying the HFD method for research and medical diagnosis make it stand out from the widely used linear methods. However, only a combination of HFD with other nonlinear methods ensures reliable and accurate analysis of a wide range of neurophysiological signals.
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Affiliation(s)
- Srdjan Kesić
- University of Belgrade, Institute for Biological Research "Siniša Stanković", Department of Neurophysiology, Bulevar Despota Stefana 142, 11060 Belgrade, Serbia
| | - Sladjana Z Spasić
- University of Belgrade, Institute for Multidisciplinary Research, Department of Life Sciences, Kneza Višeslava 1, 11030 Belgrade, Serbia; Singidunum University, Danijelova 32, 11010 Belgrade, Serbia.
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6
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Moezi L, Hosseini M, Oveisi S, Niknahad H, Shafaroodi H. The Effects of Sub-Chronic Treatment with Aripiprazole on Pentylenetetrazole- and Electroshock-Induced Seizures in Mice: The Role of Nitric Oxide. Pharmacology 2015; 95:264-70. [PMID: 26022738 DOI: 10.1159/000381550] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 03/09/2015] [Indexed: 11/19/2022]
Abstract
Almost all antipsychotics have been associated with a risk of epileptic seizure provocation. Aripiprazole is a novel atypical antipsychotic. The risk of seizures with aripiprazole is reported to be the lowest among atypical agents. In this study, we investigated the effect of aripiprazole on seizure of mice in sub-chronic treatments. We also examined the interaction of nitric oxide (NO) with aripiprazole in seizure experiments. Mice received aripiprazole for 6 days and then on the 7th day aripiprazole was injected 60 min before intraperitoneal pentylenetetrazole or electroshock. L-NAME (non-selective NO synthase (NOS) inhibitor), 7-nitroindazole (neuronal NOS selective inhibitor), aminoguanidine (inducible NOS selective inhibitors) or L-arginine (NO donor), all were injected 5 min before aripiprazole in separate groups. The results of both seizure models demonstrated anti-epileptic properties of aripiprazole in sub-chronic administrations. Co-administration of aripiprazole and selective and non-selective NOS inhibitors prevented the anticonvulsant effect of aripiprazole. While L-arginine and aripiprazole co-administration increased the clonic seizure threshold and protection against tonic seizure and death, these effects were not significant. The current results indicated that aripiprazole has anticonvulsant effects probably through the release of NO.
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Affiliation(s)
- Leila Moezi
- Department of Pharmacology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
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7
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Buckmaster PS, Wen X, Toyoda I, Gulland FMD, Van Bonn W. Hippocampal neuropathology of domoic acid-induced epilepsy in California sea lions (Zalophus californianus). J Comp Neurol 2014; 522:1691-706. [PMID: 24638960 DOI: 10.1002/cne.23509] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 11/21/2013] [Accepted: 11/21/2013] [Indexed: 12/24/2022]
Abstract
California sea lions (Zalophus californianus) are abundant human-sized carnivores with large gyrencephalic brains. They develop epilepsy after experiencing status epilepticus when naturally exposed to domoic acid. We tested whether sea lions previously exposed to DA (chronic DA sea lions) display hippocampal neuropathology similar to that of human patients with temporal lobe epilepsy. Hippocampi were obtained from control and chronic DA sea lions. Stereology was used to estimate numbers of Nissl-stained neurons per hippocampus in the granule cell layer, hilus, and pyramidal cell layer of CA3, CA2, and CA1 subfields. Adjacent sections were processed for somatostatin immunoreactivity or Timm-stained, and the extent of mossy fiber sprouting was measured stereologically. Chronic DA sea lions displayed hippocampal neuron loss in patterns and extents similar but not identical to those reported previously for human patients with temporal lobe epilepsy. Similar to human patients, hippocampal sclerosis in sea lions was unilateral in 79% of cases, mossy fiber sprouting was a common neuropathological abnormality, and somatostatin-immunoreactive axons were exuberant in the dentate gyrus despite loss of immunopositive hilar neurons. Thus, hippocampal neuropathology of chronic DA sea lions is similar to that of human patients with temporal lobe epilepsy.
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Affiliation(s)
- Paul S Buckmaster
- Department of Comparative Medicine, Stanford University, Stanford, California, 94305; Department of Neurology & Neurological Sciences, Stanford University, Stanford, California, 94305
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8
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Kirkley KS, Madl JE, Duncan C, Gulland FM, Tjalkens RB. Domoic acid-induced seizures in California sea lions (Zalophus californianus) are associated with neuroinflammatory brain injury. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2014; 156:259-68. [PMID: 25286249 DOI: 10.1016/j.aquatox.2014.09.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 09/04/2014] [Accepted: 09/08/2014] [Indexed: 05/16/2023]
Abstract
California sea lions (CSLs) exposed to the marine biotoxin domoic acid (DA) develop an acute or chronic toxicosis marked by seizures and act as sentinels of the disease. Experimental evidence suggests that oxidative stress and neuroinflammation are important mechanisms underlying the seizurogenic potential of environmental toxicants but these pathways are relatively unstudied in CSLs. In the current study, we investigated the role of glutamate-glutamine changes and gliosis in DA-exposed CSLs to better understand the neurotoxic mechanisms occurring during DA toxicity. Sections from archived hippocampi from control and CSLs diagnosed with DA toxicosis were immunofluorescently stained for markers of gliosis, oxidative/nitrative stress and changes in glutamine synthetase (GS). Quantitative assessment revealed increasing loss of microtubule associated protein-2 positive neurons with elevations in 4-hydroxynonenal correlating with chronicity of exposure, whereas the pattern of activated glia expressing nitric oxide synthase 2 and tumor necrosis factor followed pathological severity. There was no significant change in the amount of GS positive cells but there was increased 3-nitrotyrosine in GS expressing cells and in neurons, particularly in animals with chronic DA toxicosis. These changes were consistently seen in the dentate gyrus and in the cornu ammonis (CA) sectors CA3, CA4, and CA1. The results of this study indicate that gliosis and resultant changes in GS are likely important mechanisms in DA-induced seizure that need to be further explored as potential therapies in treating exposed wildlife.
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Affiliation(s)
- Kelly S Kirkley
- Center for Environmental Medicine, Colorado State University, Fort Collins, CO, USA
| | - James E Madl
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Colleen Duncan
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, USA
| | - Frances M Gulland
- The Marine Mammal Center, 1065 Fort Cronkhite, Sausalito, CA 94965, USA
| | - Ronald B Tjalkens
- Center for Environmental Medicine, Colorado State University, Fort Collins, CO, USA.
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9
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Daniels O, Fabbro L, Makiela S. The effects of the toxic cyanobacterium Limnothrix (strain AC0243) on Bufo marinus larvae. Toxins (Basel) 2014; 6:1021-35. [PMID: 24662524 PMCID: PMC3968374 DOI: 10.3390/toxins6031021] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 02/17/2014] [Accepted: 02/20/2014] [Indexed: 02/07/2023] Open
Abstract
Limnothrix (strain AC0243) is a cyanobacterium, which has only recently been identified as toxin producing. Under laboratory conditions, Bufo marinus larvae were exposed to 100,000 cells mL(-1) of Limnothrix (strain AC0243) live cultures for seven days. Histological examinations were conducted post mortem and revealed damage to the notochord, eyes, brain, liver, kidney, pancreas, gastrointestinal tract, and heart. The histopathological results highlight the toxicological impact of this strain, particularly during developmental stages. Toxicological similarities to β-N-Methylamino-L-alanine are discussed.
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Affiliation(s)
- Olivia Daniels
- School of Medical and Applied Sciences, Central Queensland University, Rockhampton 4701, Australia.
| | - Larelle Fabbro
- School of Medical and Applied Sciences, Central Queensland University, Rockhampton 4701, Australia.
| | - Sandrine Makiela
- School of Medical and Applied Sciences, Central Queensland University, Rockhampton 4701, Australia.
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10
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Domoic acid epileptic disease. Mar Drugs 2014; 12:1185-207. [PMID: 24663110 PMCID: PMC3967204 DOI: 10.3390/md12031185] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 01/08/2014] [Accepted: 02/08/2014] [Indexed: 12/23/2022] Open
Abstract
Domoic acid epileptic disease is characterized by spontaneous recurrent seizures weeks to months after domoic acid exposure. The potential for this disease was first recognized in a human case study of temporal lobe epilepsy after the 1987 amnesic shellfish-poisoning event in Quebec, and was characterized as a chronic epileptic syndrome in California sea lions through investigation of a series of domoic acid poisoning cases between 1998 and 2006. The sea lion study provided a breadth of insight into clinical presentations, unusual behaviors, brain pathology, and epidemiology. A rat model that replicates key observations of the chronic epileptic syndrome in sea lions has been applied to identify the progression of the epileptic disease state, its relationship to behavioral manifestations, and to define the neural systems involved in these behavioral disorders. Here, we present the concept of domoic acid epileptic disease as a delayed manifestation of domoic acid poisoning and review the state of knowledge for this disease state in affected humans and sea lions. We discuss causative mechanisms and neural underpinnings of disease maturation revealed by the rat model to present the concept for olfactory origin of an epileptic disease; triggered in dendodendritic synapases of the olfactory bulb and maturing in the olfactory cortex. We conclude with updated information on populations at risk, medical diagnosis, treatment, and prognosis.
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11
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Hippocampal physiology, structure and function and the neuroscience of schizophrenia: a unified account of declarative memory deficits, working memory deficits and schizophrenic symptoms. Behav Sci (Basel) 2013; 3:298-315. [PMID: 25379240 PMCID: PMC4217628 DOI: 10.3390/bs3020298] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Revised: 05/30/2013] [Accepted: 06/08/2013] [Indexed: 01/06/2023] Open
Abstract
Memory impairment is a consistent feature of the schizophrenic syndrome. Hippocampal dysfunction has also been consistently demonstrated. This review will discuss neurophysiological and neuroanatomical aspects of memory formation and how they relate to memory impairment in schizophrenia. An understanding of the cellular physiology and connectivity of the hippocampus with other regions can also aid in understanding the relationship between schizophrenic declarative or relational memory deficits, working memory deficits and the clinical symptoms of the syndrome.
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12
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Osako K, Teixeira VL. Natural Products from Marine Algae of the Genus Osmundaria(Rhodophyceae, Ceramiales). Nat Prod Commun 2013. [DOI: 10.1177/1934578x1300800433] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The present work is a review of the natural products isolated from red marine algae of the genus Osmundaria (including Vidalia), which intends to encompass their occurrence in the species of this genus, the possible synonymies, their geographic distribution, their structural variety and their biological potential as prototypes for the pharmaceutical industry and as active principles of cosmetics. At the end, we provide a table with these natural products and their biological activities.
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Affiliation(s)
- Kelvin Osako
- Programa de Pós-Graduação em Ciências e Biotecnologia, Instituto de Biologia, Universidade Federal Fluminense, Niterói/Rio de Janeiro, Brazil 24210-130
| | - Valéria Laneuville Teixeira
- Programa de Pós-Graduação em Ciências e Biotecnologia, Instituto de Biologia, Universidade Federal Fluminense, Niterói/Rio de Janeiro, Brazil 24210-130
- Departamento de Biologia Marinha, Instituto de Biologia, Universidade Federal Fluminense, Niterói/Rio de Janeiro, Brazil, 24001-970
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13
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Wu DM, Lu J, Zheng YL, Zhang YQ, Hu B, Cheng W, Zhang ZF, Li MQ. Small interfering RNA-mediated knockdown of protein kinase C zeta attenuates domoic acid-induced cognitive deficits in mice. Toxicol Sci 2012; 128:209-22. [PMID: 22474074 DOI: 10.1093/toxsci/kfs124] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Accumulated evidence indicates that domoic acid (DA)-induced excitatory neuronal injury is associated with excessive reactive oxygen species (ROS) production. Protein kinase C zeta (PKC-ζ)/nicotinamide adenine dinucleotide phosphate (NOX) signaling regulates ROS levels and is involved in various neurodegenerative disorders including excitoneurotoxicity. Our previous studies have demonstrated that ROS-induced activation of the stress-activated protein kinase/c-jun-N-terminal kinase (SAPK/JNK) pathway plays a key role in the pathogenesis of cognitive deficits induced by DA. However, the precise biological mechanisms underlying these effects are not well understood. In this study, we investigate whether the PKC-ζ mediates DA-induced cognitive deficits and further explored the potential molecular processes. DA treatment significantly increased the expression of PI3K p85α, and PKC-ζ in the hippocampus of mice, which promoted the p47phox phosphorylation and expression, enhanced NOX activity, and increased the levels of ROS and protein carbonyls. In turn, the abnormal ROS levels in the hippocampus of DA-treated mice activated SAPK/JNK pathway, decreased FoxO1 phosphorylation, stimulated the nuclear translocation of FoxO1, activated FasL/Fas signaling, and promoted the activation of caspase-8 and caspase-3, which resulted in neuron apoptosis and cognitive deficits in mice. However, PKC-ζ knockdown reversed these changes in mice. It was further demonstrated that FoxO1 was a downstream target of SAPK/JNK signaling by FoxO1 small interfering RNA and SP600125 (an inhibitor of SAPK/JNK pathway) treatment. Additionally, SP600125 treatment or FoxO1 knockdown also blocked FasL/Fas signaling-dependent apoptosis and improved DA-induced cognitive deficits in the hippocampus of mice. These results suggest that PKC-ζ could be a possible target for the prevention or treatment of cognitive deficits in excitotoxic and other brain disorders.
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Affiliation(s)
- Dong-mei Wu
- Department of Environmental Engineering, School of Environment and Spatial Informatics, China University of Mining and Technology, Xuzhou, Jiangsu Province 221008, People's Republic of China
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14
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Zhou BT, Zhou QH, Yin JY, Li GL, Xu XJ, Qu J, Liu D, Zhou HH, Liu ZQ. Comprehensive analysis of the association of SCN1A gene polymorphisms with the retention rate of carbamazepine following monotherapy for new-onset focal seizures in the Chinese Han population. Clin Exp Pharmacol Physiol 2012; 39:379-84. [PMID: 22292851 DOI: 10.1111/j.1440-1681.2012.05680.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
| | - Qiu-Hong Zhou
- Department ofEndocrinology; Xiang-Ya Hospital of Central South University; Hunan; China
| | - Ji-Ye Yin
- Institute of Clinical Pharmacology; Hunan Key Laboratory of Pharmacogenetics; Central South University Xiang-Ya School of Medicine; Hunan; China
| | - Guo-Liang Li
- Department of Neurology; Xiang-Ya Hospital of Central South University; Hunan; China
| | - Xiao-Jing Xu
- Institute of Clinical Pharmacology; Hunan Key Laboratory of Pharmacogenetics; Central South University Xiang-Ya School of Medicine; Hunan; China
| | - Jian Qu
- Institute of Clinical Pharmacology; Hunan Key Laboratory of Pharmacogenetics; Central South University Xiang-Ya School of Medicine; Hunan; China
| | - Ding Liu
- Department of Neurology; Third Xiang-Ya Hospital of Central South University; Hunan; China
| | - Hong-Hao Zhou
- Institute of Clinical Pharmacology; Hunan Key Laboratory of Pharmacogenetics; Central South University Xiang-Ya School of Medicine; Hunan; China
| | - Zhao-Qian Liu
- Institute of Clinical Pharmacology; Hunan Key Laboratory of Pharmacogenetics; Central South University Xiang-Ya School of Medicine; Hunan; China
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15
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Lu J, Wu DM, Zheng YL, Hu B, Cheng W, Zhang ZF. Purple sweet potato color attenuates domoic acid-induced cognitive deficits by promoting estrogen receptor-α-mediated mitochondrial biogenesis signaling in mice. Free Radic Biol Med 2012; 52:646-659. [PMID: 22178976 DOI: 10.1016/j.freeradbiomed.2011.11.016] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Revised: 11/04/2011] [Accepted: 11/09/2011] [Indexed: 11/28/2022]
Abstract
Recent findings suggest that endoplasmic reticulum stress may be involved in the pathogenesis of domoic acid-induced neurodegeneration. Purple sweet potato color, a class of naturally occurring anthocyanins, has beneficial health and biological effects. Recent studies have also shown that anthocyanins have estrogenic activity and can enhance estrogen receptor-α expression. In this study, we evaluated the effect of purple sweet potato color on cognitive deficits induced by hippocampal mitochondrial dysfunction in domoic acid-treated mice and explored the potential mechanisms underlying this effect. Our results showed that the oral administration of purple sweet potato color to domoic acid-treated mice significantly improved their behavioral performance in a step-through passive avoidance task and a Morris water maze task. These improvements were mediated, at least in part, by a stimulation of estrogen receptor-α-mediated mitochondrial biogenesis signaling and by decreases in the expression of p47phox and gp91phox. Decreases in reactive oxygen species and protein carbonylation were also observed, along with a blockade of the endoplasmic reticulum stress pathway. Furthermore, purple sweet potato color significantly suppressed endoplasmic reticulum stress-induced apoptosis, which prevented neuron loss and restored the expression of memory-related proteins. However, knockdown of estrogen receptor-α using short hairpin RNA only partially blocked the neuroprotective effects of purple sweet potato color in the hippocampus of mice cotreated with purple sweet potato color and domoic acid, indicating that purple sweet potato color acts through multiple pathways. These results suggest that purple sweet potato color could be a possible candidate for the prevention and treatment of cognitive deficits in excitotoxic and other brain disorders.
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Affiliation(s)
- Jun Lu
- Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Science, Xuzhou Normal University, Xuzhou 221116, Jiangsu Province, People's Republic of China
| | - Dong-Mei Wu
- Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Science, Xuzhou Normal University, Xuzhou 221116, Jiangsu Province, People's Republic of China; School of Environment and Spatial Informatics, China University of Mining and Technology, Xuzhou 221008, Jiangsu Province, People's Republic of China
| | - Yuan-Lin Zheng
- Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Science, Xuzhou Normal University, Xuzhou 221116, Jiangsu Province, People's Republic of China.
| | - Bin Hu
- Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Science, Xuzhou Normal University, Xuzhou 221116, Jiangsu Province, People's Republic of China
| | - Wei Cheng
- School of Environment and Spatial Informatics, China University of Mining and Technology, Xuzhou 221008, Jiangsu Province, People's Republic of China
| | - Zi-Feng Zhang
- Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Science, Xuzhou Normal University, Xuzhou 221116, Jiangsu Province, People's Republic of China
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16
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Yuan Y. Methylmercury: a potential environmental risk factor contributing to epileptogenesis. Neurotoxicology 2012; 33:119-26. [PMID: 22206970 PMCID: PMC3285480 DOI: 10.1016/j.neuro.2011.12.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Revised: 12/12/2011] [Accepted: 12/14/2011] [Indexed: 12/29/2022]
Abstract
Epilepsy or seizure disorder is one of the most common neurological diseases in humans. Although genetic mutations in ion channels and receptors and some other risk factors such as brain injury are linked to epileptogenesis, the underlying cause for the majority of epilepsy cases remains unknown. Gene-environment interactions are thought to play a critical role in the etiology of epilepsy. Exposure to environmental chemicals is an important risk factor. Methylmercury (MeHg) is a prominent environmental neurotoxicant, which targets primarily the central nervous system (CNS). Patients or animals with acute or chronic MeHg poisoning often display epileptic seizures or show increased susceptibility to seizures, suggesting that MeHg exposure may be associated with epileptogenesis. This mini-review highlights the effects of MeHg exposure, especially developmental exposure, on the susceptibility of humans and animals to seizures, and discusses the potential role of low level MeHg exposure in epileptogenesis. This review also proposes that a preferential effect of MeHg on the inhibitory GABAergic system, leading to disinhibition of excitatory glutamatergic function, may be one of the potential mechanisms underlying MeHg-induced changes in seizure susceptibility.
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Affiliation(s)
- Yukun Yuan
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824, USA.
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17
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Costa LG, Giordano G, Faustman EM. Domoic acid as a developmental neurotoxin. Neurotoxicology 2010; 31:409-23. [PMID: 20471419 PMCID: PMC2934754 DOI: 10.1016/j.neuro.2010.05.003] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2010] [Revised: 05/04/2010] [Accepted: 05/05/2010] [Indexed: 11/21/2022]
Abstract
Domoic acid (DomA) is an excitatory amino acid which can accumulate in shellfish and finfish under certain environmental conditions. DomA is a potent neurotoxin. In humans and in non-human primates, oral exposure to a few mg/kg DomA elicits gastrointestinal effects, while slightly higher doses cause neurological symptoms, seizures, memory impairment, and limbic system degeneration. In rodents, which appear to be less sensitive than humans or non-human primates, oral doses cause behavioral abnormalities (e.g. hindlimb scratching), followed by seizures and hippocampal degeneration. Similar effects are also seen in other species (from sea lions to zebrafish), indicating that DomA exerts similar neurotoxic effects across species. The neurotoxicity of DomA is ascribed to its ability to interact and activate the AMPA/KA receptors, a subfamily of receptors for the neuroexcitatory neurotransmitter glutamate. Studies exploring the neurotoxic effects of DomA on the developing nervous system indicate that DomA elicits similar behavioral, biochemical and morphological effects as in adult animals. However, most importantly, developmental neurotoxicity is seen at doses of DomA that are one to two orders of magnitude lower than those exerting neurotoxicity in adults. This difference may be due to toxicokinetic and/or toxicodynamic differences. Estimated safe doses may be exceeded in adults by high consumption of shellfish contaminated with DomA at the current limit of 20 microg/g. Given the potential higher susceptibility of the young to DomA neurotoxicity, additional studies investigating exposure to, and effects of this neurotoxin during brain development are warranted.
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Affiliation(s)
- Lucio G Costa
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA 98105, USA.
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