Comparison of the effects of losigamone and its isomers on maximal electroshock induced convulsions in mice and on three different patterns of low magnesium induced epileptiform activity in slices of the rat temporal cortex

1992 ◽  
Vol 345 (1) ◽  
Author(s):  
C.L. Zhang ◽  
S.S. Chatterjee ◽  
U. Stein ◽  
U. Heinemann
Keyword(s):  
Epileptiform Activity ◽  
Temporal Cortex ◽  
Maximal Electroshock ◽  
Low Magnesium

Zinc and glycine do not modify low-magnesium-induced epileptiform activity in the immature neocortex in vitro

1989 ◽  
Vol 3 (2) ◽  
pp. 174-177 ◽  
Author(s):  
Elisabeth Hegstad ◽  
Iver A Langmoen ◽  
John J Hablitz
Keyword(s):  
Epileptiform Activity ◽  
Low Magnesium

scholarly journals Effect of sevoflurane on high-frequency brain electrical activity

2020 ◽  
Vol 6 (6) ◽  
pp. 23-28
Author(s):  
N. B. Arkhipova ◽  
M. V. Aleksandrov
Keyword(s):  
Electrical Activity ◽  
High Frequency ◽  
Slow Wave Sleep ◽  
Epileptiform Activity ◽  
Temporal Cortex ◽  
Epileptogenic Zone ◽  
Brain Electrical Activity ◽  
Surgery Outcome ◽  
Wide Range ◽  
Deep Brain

Background. In 30 % of cases with epilepsy, it qualifies as medically intractable and requires surgical treatment. The need for improvement of epilepsy surgery effectiveness demands updating of the preoperative assessment protocols. Intraoperative wide-range electrocorticography is a novel technique for defining resection volume in focal structural epilepsy. Combined analysis of high-frequency and epileptiform activity provides additional information and allows prognosticating of surgery outcome. However, consistent evaluation of intraoperative monitoring results is only possible when general anesthetic effect on brain electrical activity is taken into account.Objective. This study was aimed at evaluation of anesthetic gas sevoflurane effect on high-frequency brain electrical activity, recorded directly from the cortex or deep brain structures.Design and methods. Eight patients were included in this study (2 females, 6 males), aged 19 to 47, with a long-term epilepsy (disease duration 15 to 38 years). Prolonged electrocorticographic monitoring was indicated to these patients, combined with eloquent zones mapping in some cases. Patients were implanted with grid electrodes on frontal and temporal cortex, and deep brain Spencer electrodes into the mesial temporal lobe. Wide-range electrocorticography was recorded during slow-wave sleep and intraoperatively under sevoflurane anesthesia. Pathological high-frequency oscillations (pHFOs) rate was counted.Results. In seven patients pHFOs were recorded extraoperatively. Pathological HFO rate varied between 13 and 30 % (mean — 19 %). Distribution of pHFO did not change due to anesthesia effects. Mean background noise amplitude was significantly decreased intraoperatively (z = 2.45; p = 0.014). This effect facilitated visual marking of pHFOs. There were no trends in comparison between extraoperative and intraoperative pHFO rate.Conclusion. Well-controlled levels of general anesthesia obtained with sevoflurane (0,9-1,1 MAC) showed minimal effect on high-frequency brain electrical activity. This allows thorough analysis of wide-range electrocorticogiaphy without waking the patient and provides more information about the extension of the epileptogenic zone and its resection rate intraoperatively.

scholarly journals Ceftriaxone Treatment Affects EAAT2 Expression and Glutamatergic Neurotransmission and Exerts a Weak Anticonvulsant Effect in Young Rats

2019 ◽  
Vol 20 (23) ◽  
pp. 5852 ◽  
Author(s):  
Zaitsev ◽  
Malkin ◽  
Postnikova ◽  
Smolensky ◽  
Zubareva ◽  
...  
Keyword(s):  
Excitatory Amino Acid ◽  
Glutamate Uptake ◽  
Temporal Cortex ◽  
Young Male ◽  
Anticonvulsant Effect ◽  
Maximal Electroshock ◽  
Glutamatergic Neurotransmission ◽  
Excitatory Amino Acid Transporter ◽  
Young Rats ◽  
Wide Range

Epilepsy is a common neurological disorder. Despite the availability of a wide range of antiepileptic drugs, these are unsuccessful in preventing seizures in 20–30% of patients. Therefore, new pharmacological strategies are urgently required to control seizures. Modulation of glutamate uptake may have potential in the treatment of pharmacoresistant forms of epilepsy. Previous research showed that the antibiotic ceftriaxone (CTX) increased the expression and functional activity of excitatory amino acid transporter 2 (EAAT2) and exerted considerable anticonvulsant effects. However, other studies did not confirm a significant anticonvulsant effect of CTX administration. We investigated the impacts of CTX treatment on EAAT expression and glutamatergic neurotransmission, as well its anticonvulsant action, in young male Wistar rats. As shown by a quantitative real-time polymerase chain reaction (qPCR) assay and a Western blot analysis, the mRNA but not the protein level of EAAT2 increased in the hippocampus following CTX treatment. Repetitive CTX administration had only a mild anticonvulsant effect on pentylenetetrazol (PTZ)-induced convulsions in a maximal electroshock threshold test (MEST). CTX treatment did not affect the glutamatergic neurotransmission, including synaptic efficacy, short-term facilitation, or the summation of excitatory postsynaptic potentials (EPSPs) in the hippocampus and temporal cortex. However, it decreased the field EPSP (fEPSP) amplitudes evoked by intense electrical stimulation. In conclusion, in young rats, CTX treatment did not induce overexpression of EAAT2, therefore exerting only a weak antiseizure effect. Our data provide new insight into the effects of modulation of EAAT2 expression on brain functioning.

Inhibitory mechanisms in epileptiform activity induced by low magnesium

1995 ◽  
Vol 430 (2) ◽  
pp. 238-245 ◽  
Author(s):  
Christian H. A. Westerhoff ◽  
Roland Domann ◽  
Otto W. Witte
Keyword(s):  
Epileptiform Activity ◽  
Low Magnesium ◽  
Inhibitory Mechanisms

Acute effects of γ-vinyl-GABA on low-magnesium evoked epileptiform activity in vitro

2000 ◽  
Vol 40 (2-3) ◽  
pp. 99-107 ◽  
Author(s):  
Dominique Engel ◽  
Ute Endermann ◽  
Christiane Frahm ◽  
Uwe Heinemann ◽  
Andreas Draguhn
Keyword(s):  
Epileptiform Activity ◽  
Acute Effects ◽  
Low Magnesium

Epileptiform activity in combined slices of the hippocampus, subiculum and entorhinal cortex during perfusion with low magnesium medium

1986 ◽  
Vol 69 (2) ◽  
pp. 156-161 ◽  
Author(s):  
H. Walther ◽  
J.D.C. Lambert ◽  
R.S.G. Jones ◽  
U. Heinemann ◽  
B. Hamon
Keyword(s):  
Entorhinal Cortex ◽  
Epileptiform Activity ◽  
Low Magnesium

scholarly journals Comparison of Effects of Valproate and Trans-2-en-Valproate on Different Forms of Epileptiform Activity in Rat Hippocampal and Temporal Cortex Slices

Epilepsia ◽  
1998 ◽  
Vol 39 (3) ◽  
pp. 251-258 ◽  
Author(s):  
S. Sokolova ◽  
D. Schmitz ◽  
C. L. Zhang ◽  
W. Loscher ◽  
U. Heinemann
Keyword(s):  
Epileptiform Activity ◽  
Temporal Cortex ◽  
Cortex Slices

scholarly journals Paradoxical Anticonvulsant Effect of Cefepime in the Pentylenetetrazole Model of Seizures in Rats

2020 ◽  
Vol 13 (5) ◽  
pp. 80
Author(s):  
Dmitry V. Amakhin ◽  
Ilya V. Smolensky ◽  
Elena B. Soboleva ◽  
Aleksey V. Zaitsev
Keyword(s):  
Gabaa Receptor ◽  
Time Constant ◽  
Decay Time ◽  
Epileptiform Activity ◽  
Decay Time Constant ◽  
Anticonvulsant Effect ◽  
Maximal Electroshock ◽  
Current Decay ◽  
Whole Cell Patch Clamp

Many β-lactam antibiotics, including cephalosporins, may cause neurotoxic and proconvulsant effects. The main molecular mechanism of such effects is considered to be γ-aminobutyric acid type a (GABAa) receptor blockade, leading to the suppression of GABAergic inhibition and subsequent overexcitation. We found that cefepime (CFP), a cephalosporin, has a pronounced antiepileptic effect in the pentylenetetrazole (PTZ)-induced seizure model by decreasing the duration and severity of the seizure and animal mortality. This effect was specific to the PTZ model. In line with findings of previous studies, CFP exhibited a proconvulsant effect in other models, including the maximal electroshock model and 4-aminopyridine model of epileptiform activity, in vitro. To determine the antiepileptic mechanism of CFP in the PTZ model, we used whole-cell patch-clamp recordings. We demonstrated that CFP or PTZ decreased the amplitude of GABAa receptor-mediated postsynaptic currents. PTZ also decreased the current decay time constant and temporal summation of synaptic responses. In contrast, CFP slightly increased the decay time constant and did not affect summation. When applied together, CFP prevented alterations to the summation of responses by PTZ, strongly reducing the effects of PTZ on repetitive inhibitory synaptic transmission. The latter may explain the antiepileptic effect of CFP in the PTZ model.

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