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Postnikova TY, Griflyuk AV, Zhigulin AS, Soboleva EB, Barygin OI, Amakhin DV, Zaitsev AV. Febrile Seizures Cause a Rapid Depletion of Calcium-Permeable AMPA Receptors at the Synapses of Principal Neurons in the Entorhinal Cortex and Hippocampus of the Rat. Int J Mol Sci 2023; 24:12621. [PMID: 37628802 PMCID: PMC10454714 DOI: 10.3390/ijms241612621] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 08/01/2023] [Accepted: 08/09/2023] [Indexed: 08/27/2023] Open
Abstract
Febrile seizures (FSs) are a relatively common early-life condition that can cause CNS developmental disorders, but the specific mechanisms of action of FS are poorly understood. In this work, we used hyperthermia-induced FS in 10-day-old rats. We demonstrated that the efficiency of glutamatergic synaptic transmission decreased rapidly after FS by recording local field potentials. This effect was transient, and after two days there were no differences between control and post-FS groups. During early ontogeny, the proportion of calcium-permeable (CP)-AMPA receptors in the synapses of the principal cortical and hippocampal neurons is high. Therefore, rapid internalization of CP-AMPA receptors may be one of the mechanisms underlying this phenomenon. Using the whole-cell patch-clamp method and the selective CP-AMPA receptor blocker IEM-1460, we tested whether the proportion of CP-AMPA receptors changed. We have demonstrated that FS rapidly reduces synaptic CP-AMPA receptors in both the hippocampus and the entorhinal cortex. This process was accompanied by a sharp decrease in the calcium permeability of the membrane of principal neurons, which we revealed in experiments with kainate-induced cobalt uptake. Our experiments show that FSs cause rapid changes in the function of the glutamatergic system, which may have compensatory effects that prevent excessive excitotoxicity and neuronal death.
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Affiliation(s)
| | | | | | | | | | | | - Aleksey V. Zaitsev
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS, 44, Toreza Prospekt, Saint Petersburg 194223, Russia; (T.Y.P.); (A.V.G.); (A.S.Z.); (E.B.S.); (O.I.B.); (D.V.A.)
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Zubareva OE, Dyomina AV, Kovalenko AA, Roginskaya AI, Melik-Kasumov TB, Korneeva MA, Chuprina AV, Zhabinskaya AA, Kolyhan SA, Zakharova MV, Gryaznova MO, Zaitsev AV. Beneficial Effects of Probiotic Bifidobacterium longum in a Lithium-Pilocarpine Model of Temporal Lobe Epilepsy in Rats. Int J Mol Sci 2023; 24:ijms24098451. [PMID: 37176158 PMCID: PMC10179354 DOI: 10.3390/ijms24098451] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 05/01/2023] [Accepted: 05/05/2023] [Indexed: 05/15/2023] Open
Abstract
Epilepsy is a challenging brain disorder that is often difficult to treat with conventional therapies. The gut microbiota has been shown to play an important role in the development of neuropsychiatric disorders, including epilepsy. In this study, the effects of Bifidobacterium longum, a probiotic, on inflammation, neuronal degeneration, and behavior are evaluated in a lithium-pilocarpine model of temporal lobe epilepsy (TLE) induced in young adult rats. B. longum was administered orally at a dose of 109 CFU/rat for 30 days after pilocarpine injection. The results show that B. longum treatment has beneficial effects on the TLE-induced changes in anxiety levels, neuronal death in the amygdala, and body weight recovery. In addition, B. longum increased the expression of anti-inflammatory and neuroprotective genes, such as Il1rn and Pparg. However, the probiotic had little effect on TLE-induced astrogliosis and microgliosis and did not reduce neuronal death in the hippocampus and temporal cortex. The study suggests that B. longum may have a beneficial effect on TLE and may provide valuable insights into the role of gut bacteria in epileptogenesis. In addition, the results show that B. longum may be a promising drug for the comprehensive treatment of epilepsy.
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Affiliation(s)
- Olga E Zubareva
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 194223 Saint Petersburg, Russia
| | - Alexandra V Dyomina
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 194223 Saint Petersburg, Russia
| | - Anna A Kovalenko
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 194223 Saint Petersburg, Russia
| | - Anna I Roginskaya
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 194223 Saint Petersburg, Russia
| | - Tigran B Melik-Kasumov
- Institute of Physiology of the National Academy of Sciences of Belarus, 220072 Minsk, Belarus
| | - Marina A Korneeva
- Institute of Physiology of the National Academy of Sciences of Belarus, 220072 Minsk, Belarus
| | - Alesya V Chuprina
- Institute of Physiology of the National Academy of Sciences of Belarus, 220072 Minsk, Belarus
| | - Alesya A Zhabinskaya
- Institute of Physiology of the National Academy of Sciences of Belarus, 220072 Minsk, Belarus
| | - Stepan A Kolyhan
- Institute of Physiology of the National Academy of Sciences of Belarus, 220072 Minsk, Belarus
| | - Maria V Zakharova
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 194223 Saint Petersburg, Russia
| | - Marusya O Gryaznova
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 194223 Saint Petersburg, Russia
| | - Aleksey V Zaitsev
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 194223 Saint Petersburg, Russia
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Diespirov GP, Postnikova TY, Griflyuk AV, Kovalenko AA, Zaitsev AV. Alterations in the Properties of the Rat Hippocampus Glutamatergic System in the Lithium-Pilocarpine Model of Temporal Lobe Epilepsy. BIOCHEMISTRY (MOSCOW) 2023; 88:353-363. [PMID: 37076282 DOI: 10.1134/s0006297923030057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/28/2023]
Abstract
Status epilepticus (SE) triggers many not yet fully understood pathological changes in the nervous system that can lead to the development of epilepsy. In this work, we studied the effects of SE on the properties of excitatory glutamatergic transmission in the hippocampus in the lithium-pilocarpine model of temporal lobe epilepsy in rats. The studies were performed 1 day (acute phase), 3 and 7 days (latent phase), and 30 to 80 days (chronic phase) after SE. According to RT-qPCR data, expression of the genes coding for the AMPA receptor subunits GluA1 and GluA2 was downregulated in the latent phase, which may lead to the increased proportion of calcium-permeable AMPA receptors that play an essential role in the pathogenesis of many CNS diseases. The efficiency of excitatory synaptic neurotransmission in acute brain slices was decreased in all phases of the model, as determined by recording field responses in the CA1 region of the hippocampus in response to the stimulation of Schaffer collaterals by electric current of different strengths. However, the frequency of spontaneous excitatory postsynaptic potentials increased in the chronic phase, indicating an increased background activity of the glutamatergic system in epilepsy. This was also evidenced by a decrease in the threshold current causing hindlimb extension in the maximal electroshock seizure threshold test in rats with temporal lobe epilepsy compared to the control animals. The results suggest a series of functional changes in the properties of glutamatergic system associated with the epilepsy development and can be used to develop the antiepileptogenic therapy.
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Affiliation(s)
- Georgy P Diespirov
- Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, St. Petersburg, 194223, Russia
| | - Tatyana Y Postnikova
- Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, St. Petersburg, 194223, Russia
| | - Alexandra V Griflyuk
- Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, St. Petersburg, 194223, Russia
| | - Anna A Kovalenko
- Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, St. Petersburg, 194223, Russia
| | - Aleksey V Zaitsev
- Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, St. Petersburg, 194223, Russia.
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Postnikova TY, Trofimova AM, Zakharova MV, Nosova OI, Brazhe AR, Korzhevskii DE, Semyanov AV, Zaitsev AV. Delayed Impairment of Hippocampal Synaptic Plasticity after Pentylenetetrazole-Induced Seizures in Young Rats. Int J Mol Sci 2022; 23:ijms232113461. [PMID: 36362260 PMCID: PMC9657086 DOI: 10.3390/ijms232113461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 10/26/2022] [Accepted: 11/01/2022] [Indexed: 11/06/2022] Open
Abstract
Data on the long-term consequences of a single episode of generalized seizures in infants are inconsistent. In this study, we examined the effects of pentylenetetrazole-induced generalized seizures in three-week-old rats. One month after the seizures, we detected a moderate neuronal loss in several hippocampal regions: CA1, CA3, and hilus, but not in the dentate gyrus. In addition, long-term synaptic potentiation (LTP) was impaired. We also found that the mechanism of plasticity induction was altered: additional activation of metabotropic glutamate receptors (mGluR1) is required for LTP induction in experimental rats. This disturbance of the plasticity induction mechanism is likely due to the greater involvement of perisynaptic NMDA receptors compared to receptors located in the core part of the postsynaptic density. This hypothesis is supported by experiments with selective blockades of core-located NMDA receptors by the use-dependent blocker MK-801. MK-801 had no effect on LTP induction in experimental rats and suppressed LTP in control animals. The weakening of the function of core-located NMDA receptors may be due to the disturbed clearance of glutamate from the synaptic cleft since the distribution of the astrocytic glutamate transporter EAAT2 in experimental animals was found to be altered.
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Affiliation(s)
- Tatyana Y. Postnikova
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS, Saint Petersburg 194223, Russia
| | - Alina M. Trofimova
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS, Saint Petersburg 194223, Russia
| | - Maria V. Zakharova
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS, Saint Petersburg 194223, Russia
| | - Olga I. Nosova
- Institute of Experimental Medicine, Saint Petersburg 197022, Russia
| | - Alexey R. Brazhe
- Faculty of Biology, Moscow State University, Moscow 119234, Russia
| | | | - Alexey V. Semyanov
- Faculty of Biology, Moscow State University, Moscow 119234, Russia
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia
- Department of Clinical Pharmacology, Sechenov First Moscow State Medical University, Moscow 119435, Russia
| | - Aleksey V. Zaitsev
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS, Saint Petersburg 194223, Russia
- Correspondence:
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Kovalenko AA, Zakharova MV, Schwarz AP, Dyomina AV, Zubareva OE, Zaitsev AV. Changes in Metabotropic Glutamate Receptor Gene Expression in Rat Brain in a Lithium-Pilocarpine Model of Temporal Lobe Epilepsy. Int J Mol Sci 2022; 23:ijms23052752. [PMID: 35269897 PMCID: PMC8910969 DOI: 10.3390/ijms23052752] [Citation(s) in RCA: 2] [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: 02/08/2022] [Revised: 02/27/2022] [Accepted: 02/27/2022] [Indexed: 11/16/2022] Open
Abstract
Preventing epileptogenesis in people at risk is an unmet medical need. Metabotropic glutamate receptors (mGluRs) are promising targets for such therapy. However, drugs acting on mGluRs are not used in the clinic due to limited knowledge of the involvement of mGluRs in epileptogenesis. This study aimed to analyze the changes in gene expression of mGluR subtypes (1-5, 7, 8) in various rat brain regions in the latent and chronic phases of a lithium-pilocarpine model of epilepsy. For this study, multiplex test systems were selected and optimized to analyze mGluR gene expression using RT-qPCR. Region- and phase-specific changes in expression were revealed. During the latent phase, mGluR5 mRNA levels were increased in the dorsal and ventral hippocampus, and expression of group III genes was decreased in the hippocampus and temporal cortex, which could contribute to epileptogenesis. Most of the changes in expression detected in the latent stage were absent in the chronic stage, but mGluR8 mRNA production remained reduced in the hippocampus. Moreover, we found that gene expression of group II mGluRs was altered only in the chronic phase. The study deepened our understanding of the mechanisms of epileptogenesis and suggested that agonists of group III mGluRs are the most promising targets for preventing epilepsy.
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Postnikova TY, Diespirov GP, Amakhin DV, Vylekzhanina EN, Soboleva EB, Zaitsev AV. Impairments of Long-Term Synaptic Plasticity in the Hippocampus of Young Rats during the Latent Phase of the Lithium-Pilocarpine Model of Temporal Lobe Epilepsy. Int J Mol Sci 2021; 22:ijms222413355. [PMID: 34948152 PMCID: PMC8705146 DOI: 10.3390/ijms222413355] [Citation(s) in RCA: 3] [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: 11/02/2021] [Revised: 12/06/2021] [Accepted: 12/10/2021] [Indexed: 12/14/2022] Open
Abstract
Status epilepticus (SE) causes persistent abnormalities in the functioning of neuronal networks, often resulting in worsening epileptic seizures. Many details of cellular and molecular mechanisms of seizure-induced changes are still unknown. The lithium–pilocarpine model of epilepsy in rats reproduces many features of human temporal lobe epilepsy. In this work, using the lithium–pilocarpine model in three-week-old rats, we examined the morphological and electrophysiological changes in the hippocampus within a week following pilocarpine-induced seizures. We found that almost a third of the neurons in the hippocampus and dentate gyrus died on the first day, but this was not accompanied by impaired synaptic plasticity at that time. A diminished long-term potentiation (LTP) was observed following three days, and the negative effect of SE on plasticity increased one week later, being accompanied by astrogliosis. The attenuation of LTP was caused by the weakening of N-methyl-D-aspartate receptor (NMDAR)-dependent signaling. NMDAR-current was more than two-fold weaker during high-frequency stimulation in the post-SE rats than in the control group. Application of glial transmitter D-serine, a coagonist of NMDARs, allows the enhancement of the NMDAR-dependent current and the restoration of LTP. These results suggest that the disorder of neuron–astrocyte interactions plays a critical role in the impairment of synaptic plasticity.
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