Comparison of benzodiazepine receptor and regional cerebral blood floq imaging of epileptiform foci in hippocampal kindled rabbits: a study with in vivo double tracer autoradiography using 125I-Iomazenil and 99mTc-HMPAO

Kurokawa, Kenzo; Jibiki, Itsuki; Fukushima, Toshinobu; Tsuji, Shiro; Yamaguchi, Nariyoshi; Hisada, Kinichi

doi:10.1016/0006-8993(94)90935-0

Cited by 11 publications

(7 citation statements)

References 23 publications

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“…changes in GABAAR binding [29,51,62,67,69], in synaptic GABAergic inhibition [7,21,24,70,75,[77][78][79], in sensitivity for iontophoretically applied GABA [19] and in GABAAR mediated C1-uptake in synaptoneurosomes [66]. In this respect, it is of particular interest to compare the opposite changes in CA1-3 area, where a reduced GABAergic inhibition is manifested, with the changes in fascia dentata region where inhibition is strengthened [21,26,66,67,69,79].…”

Section: Relation Of the Observed Mrna Changes And Alterations Of Gabmentioning

confidence: 99%

“…In CA1 area of the hippocampus, experimental evidence has been found in support of this hypothesis; a reduction of inhibitory synaptic transmission takes place in the course of kindling as shown by a reduced pairedpulse inhibition of local evoked field potentials [22,24,26,77,78], a diminished sensitivity of the pyramidal neurons for iontophoretically applied GABA [20] and a reduced binding of the GABA A receptor agonist [3H]muscimol [69] and of benzodiazepines [29,67]. In sharp contrast to the decreased inhibition in CA1, in the fascia dentata paired pulse inhibition is enhanced [7,21,26,70,79], together with an increase in the amplitude of miniature inhibitory postsynaptic currents [53], and a robust increase in both [3H]muscimol and [3H]flunitrazepam binding in this area [51,62,67,69].…”

Section: Introductionmentioning

confidence: 97%

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Expression of GABAA receptor subunit mRNAs in hippocampal pyramidal and granular neurons in the kindling model of epileptogenesis: an in situ hybridization study

Kamphuis

Rijk

Silva

1995

Molecular Brain Research

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Expression of GABA-A receptor subunit in mRNAs in hippocampal pyramidal and granular neurons in the kindling model of epileptogenesis: an in situ hybridization study. Kamphuis, W.; de Rijk, T.C.; Lopes da Silva, F.H. Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Accepted 24 January 1995 AbstractTo investigate the molecular changes underlying kindling epileptogenesis in the rat hippocampus, the expression levels of the genes encoding for 13 different y-aminobutyric acid type-A receptor (GABAAR) subunits were measured in hippocampal principal neurons using in situ hybridization techniques and semi-quantitative analysis of the autoradiograms. Schaffer collateral-commissural pathway kindled rats were investigated at three different stages of kindling acquisition, at 24 h after the last seizure and at long-term (28 days) after termination of kindling stimulations. Changes were distinct for the different subunits in the three analyzed regions (CA1, CA3, fascia dentata) and also different for the various kindling stages. In all hippocampal areas at the early phases of kindling epileptogenesis, before the appearance of generalized seizures, an increase was found of those transcripts that constituted the majority of the expressed variants in control animals (al, a2, a4, /31, /32, /33, y2/y2L mRNA). In these stages, the increased levels of different variants in the granular neurons of the fascia dentata were more pronounced when compared to the pattern of changes in pyramidal cells of CA1 and CA3. In fully kindled animals, the expression levels of several subunits returned to control levels, whereas/33 and y2/y2L mRNA expression was still significantly enhanced in all areas. At long-term, few changes were encountered. The long-splice variant of 3,2 was decreased within pyramidal and granular neurons while the total level of y2 mRNA was not different from controls. The increased GABAAR subunit expression in the fascia dentata may underly the reported increased GABAAR ligand binding and the increased GABA mediated inhibition. However, the decreased GABAAR binding and the attenuation of GABAergic inhibition in CA1, could not be explained by a decrement of receptor subunit expression.

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Section: Relation Of the Observed Mrna Changes And Alterations Of Gabmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 97%

Expression of GABAA receptor subunit mRNAs in hippocampal pyramidal and granular neurons in the kindling model of epileptogenesis: an in situ hybridization study

Kamphuis

Rijk

Silva

1995

Molecular Brain Research

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“…Late IMZ-SPECT images obtained 3 hours after intravenous injection of 123 Iiomazenil reflect the distribution of central BZRs [25]. According to previous studies, the distribution of BZRs at the epileptogenic site was reduced not only in an experimental animal epilepsy model [15], but also in a resected section of the human epileptogenic tissue, which was reflected by a decrease in IMZuptake [14,26]. McDonald et al [26] showed that GABA/BZR affinity was reduced in CA1 and CA4 regions in hippocampal specimens resected from patients with intractable temporal lobe epilepsy.…”

Section: Imz-spect For Childhood Epilepsymentioning

confidence: 83%

“…Many studies have reported the usefulness of interictal/ictal cerebral blood flow single photon emission computed tomography (SPECT) [8][9][10][11][12] and interictal 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET) [2,3,7,10,13]. 123 I-iomazenil SPECT (IMZ-SPECT) was developed based on biochemical abnormalities existing in the epileptogenic brain lesion, and is able to detect the original epileptic focus effectively in the interictal state [14,15]. In the field of epilepsy surgery in adults, several studies have employed this procedure as a presurgical evaluation, suggesting its usefulness for accurate identification of the epileptogenic lesions [16][17][18].…”

Section: Introductionmentioning

confidence: 99%

Usefulness of 123I-iomazenil SPECT for childhood focal epilepsies

Okamoto

Oguni

Hirano

et al. 2011

E&S

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Purpose:We investigated the usefulness of 123 I-iomazenil (IMZ-) SPECT to detect epileptic foci in children with symptomatic focal epilepsy (SFE). Subjects: 21 children with SFE who underwent IMZ-SPECT to identify the epileptic focus were studied. Methods: We retrospectively compared the localization and lateralization of epileptic foci obtained from visualization of IMZ-SPECT images and those speculated based on a combination of clinical manifestations, EEG findings, and brain MRI. We then verified the concordance of the results between the two methods. Results: There was concordance in both lateralization and localization in 9/12 patients with temporal lobe epilepsy (75%), in 2/5 patients Correspondence to: Hirokazu Oguni, MD, Department of Pediatrics, Tokyo Women's Medical University, 8-1 Kawada-cho, Tokyo 162, hoguni@ped.twmu.ac.jp Epilepsy & Seizure Journal of Japan Epilepsy Society Vol.4 No.1 (2011)

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“…29 Autoradiography in which 125 I-Iomazenil is used in hippocampal-kindled rabbits demonstrated a decrease in the number of benzodiazepine receptors in bilateral CA3 regions regarded as propagation sites for seizure discharge, whereas rCBF decreased to a lesser extent. 28 Generally, decreases in rCBF and cerebral metabolic rate in TLE are thought to be strongly correlated with hip-pocampal cell loss and gliosis. 15 However, in our population there was no correlation between the decrease in HBF and the proportion of cells lost as estimated by VCD studies in which hippocampal specimens were used.…”

Section: Discussionmentioning

confidence: 99%

Bilateral decrease in interictal hippocampal blood flow in unilateral mesiotemporal epilepsy

Rougier¹,

Lurton²,

Bahh³

et al. 1999

Journal of Neurosurgery

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In unilateral mesiotemporal epilepsy, asymmetrical interictal hippocampal perfusion was correlated with restricted unilateral ictal discharges, whereas bilateral hippocampal hypoperfusion was correlated with ictal discharges spreading to the contralateral mesiotemporal structures. The lack of correlation between the degree of hypoperfusion and the percentage of neuron cell loss indicated that the decrease in rCBF has both functional and lesional origins.

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Comparison of benzodiazepine receptor and regional cerebral blood floq imaging of epileptiform foci in hippocampal kindled rabbits: a study with in vivo double tracer autoradiography using 125I-Iomazenil and 99mTc-HMPAO

Cited by 11 publications

References 23 publications

Expression of GABAA receptor subunit mRNAs in hippocampal pyramidal and granular neurons in the kindling model of epileptogenesis: an in situ hybridization study

Expression of GABAA receptor subunit mRNAs in hippocampal pyramidal and granular neurons in the kindling model of epileptogenesis: an in situ hybridization study

Usefulness of 123I-iomazenil SPECT for childhood focal epilepsies

Bilateral decrease in interictal hippocampal blood flow in unilateral mesiotemporal epilepsy

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