Quantitative evaluation of central-type benzodiazepine receptors with [125I] Iomazenil in experimental epileptogenesisI. The rat kainate model of temporal lobe epilepsy

Tamagami, Hiroshi; Morimoto, Kiyoshi; Watanabe, Takemi; NINOMIYA, T; Hirao, Toshihide; TANAKA, A; Kakumoto, Miki

doi:10.1016/s0920-1211(04)00143-3

Cited by 3 publications

(5 citation statements)

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“…This was followed by a persistent decrease 2-6 weeks after SE in most hippocampal regions, except for the stratum moleculare of the dentate gyrus in which the GABA A /cBZ receptor density remained increased, perhaps reflecting its gate-keeping function (Vivash et al, 2011). The general decrease at later time-points is consistent with findings from a study using 123 I-Iomazenil in the intrahippocampal KASE model (Tamagami et al, 2004) and in a seizure-susceptible model of cortical dysplasia (Morimoto et al, 2004).…”

Section: Imaging Brain Receptorssupporting

confidence: 85%

Neuroimaging in animal models of epilepsy

et al. 2017

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Epilepsy is one of the most common chronic neurological conditions worldwide. The current poor understanding and lack of reliable biomarkers of the epileptogenic process are the major limitations in the development of anti-epileptic drugs that are able to prevent or modify the underlying disease. The rapid progress in advanced imaging technologies has expanded our opportunities to study the disease in animal models of epilepsy by means of non-invasive research tools. Here we review the advances of different in vivo imaging techniques, including magnetic resonance-based and nuclear imaging-based modalities, in animal models of epilepsy. Together these techniques can be applied to visualize and quantify structural, metabolic, functional and molecular changes in longitudinal study designs to provide unique information about early pathophysiological changes and their interplay involved in epileptogenesis, monitoring the disease progression, assessing the effectiveness of possible therapies, and potentially identify translatable biomarkers for clinical use.

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Section: Imaging Brain Receptorssupporting

confidence: 85%

Neuroimaging in animal models of epilepsy

et al. 2017

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“…In the kainate model of MTLE, progressive reduction of 125 I‐IMZ binding was observed in hippocampal area CA1 (83% relative to the control level), CA2 (76%), CA3 (75%), and CA4 (90%, Fig. 3), and the decrease clearly paralleled pyramidal neuron loss (2). In contrast, 125 I‐IMZ binding significantly increased in the dentate gyrus (106%) at 1 month, but it returned nearly to the normal level at 3–6 months (Fig.…”

Section: Resultsmentioning

confidence: 93%

“…In the kainate model, status epilepticus was induced by intraamygdala microinjection of kainate (1 μg/0.5 μl) via permanently implanted guide cannula in rats, and 1, 3, or 6 months after status epilepticus, in vitro autoradiography with 123 I‐IMZ was performed (2). The number of rats killed at each of these time intervals was 12, eight, and seven kainate‐treated and 13, seven, and 10 vehicle‐treated controls.…”

Section: Methodsmentioning

confidence: 99%

“…In the meantime, [ 123 I]iomazenil ( 123 I‐IMZ) is a specific radiolabeled ligand for central‐type BZRs and is available for single‐photon emission computed tomography (SPECT) in various brain disorders, including focal epilepsies. This study was conducted to evaluate the clinical validity of central‐type BZRs and its mechanism in experimental epileptogenesis, including kainate (2), kindling, and in‐utero irradiation models (3).…”

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confidence: 99%

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Central‐type Benzodiazepine Receptors and Epileptogenesis: Basic Mechanisms and Clinical Validity

2005

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Methods: We examined interictal 123 I-IMZ SPECT in patients with mesial temporal lobe epilepsy (MTLE; n = 19) with hippocampal sclerosis and neocortical epilepsy with focal cortical dysplasia (NE-CD; n = 18), and compared those with magnetic resonance imaging (MRI) and 123 I-IMP SPECT (for regional cerebral blood flow). We also investigated in vitro autoradiography with 123 I-IMZ at various time courses in the intraamygdala kainate, amygdala kindling, and in-utero irradiation models.Results: In MTLE patients, the epileptogenic hippocampus often showed decreases in both 123 I-IMZ and 123 I-IMP SPECT. Consistent with those, marked reduction of 125 I-IMZ binding was observed in hippocampal CA1-3 regions of the kainate model, which clearly paralleled pyramidal neuronal loss. In contrast, 125 I-IMZ binding was increased in the dentate gyrus at 1 month but returned to the normal level at 3-6 months, when frequent spontaneous seizures appeared. The amygdala-kindling model demonstrated similar increases in 125 I-IMZ binding in the dentate gyrus without any changes in other brain regions. In NE-CD patients, the epileptogenic foci showed decreased 123 I-IMZ binding with relatively normal 123 I-IMP SPECT. 125 I-IMZ binding also was decreased in the cerebral cortex, hippocampus (areas CA1, 2, and 4), and caudate/putamen of the in-utero irradiation model.Conclusions: These results indicate that central-type BZRs neuroimaging is useful for detection of epileptogenic foci, but their alterations differ between epilepsy subtypes and time-courses.

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“…Animal TLE generated with intracerebral administration of KA share many features with human TLE, including loss of CA3 pyramidal neurons, sprouting of mossy fibers in the dentate gyrus, and downregula-tion of calcium binding proteins and synaptic reorganization throughout the hippocampus (Tamagami et al 2004;Shetty, Zaman, & Shetty 2003). In both animal TLE and human TLE, the mossy fiber pathway in the dentate gyrus undergoes sprouting and synaptic reorganization in response to seizures.…”

Section: Hippocampal Stem Cells Transplantation Reduces Discharges Ofmentioning

confidence: 99%

Hippocampal Stem Cell Grafting-Mediated Recovery of Injured Hippocampus in the Rat Model of Temporal Lobe Epilepsy

Shen

Liu

Huo

et al. 2010

International Journal of Neuroscience

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Hippocampal stem cells (HSCs) are considered promising donor cells to promote reorganization of degenerated regions of the injured hippocampus in the epileptic brain. However, the efficacy of HSC grafting for repairing injured hippocampus remains unclear. To address this issue, we transplanted neonatal rat HSCs into the right hippocampus in rats with kainite acid (KA)-induced epilepsy. The activity of the hippocampus and amygdala nucleus was monitored with electroencephalogram (EEG) throughout 24 weeks posttransplantation. Rats with grafted HSCs exhibited reduced frequency of epileptic wave discharge and a 50% decrease in the amplitude of discharge. At 1, 4, 8, and 24 weeks posttransplantation, the aberrant mossy fiber sprouting (MFS) was evaluated with Timm's stain and the number of CA3 pyramidal neurons was analyzed with Nissl staining. Aberrant MFS induced by KA-lesion was notably suppressed by HSC grafts beginning 4 weeks posttransplantation, and was most effective by 8 weeks. In addition, the loss of CA3 pyramidal neurons was partially restored and reached the most recovery at 8 weeks. Taken together, these results suggest that HSCs derived from the postnatal hippocampus offer a promising reparative effect on KA-induced epileptic brain.

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Quantitative evaluation of central-type benzodiazepine receptors with [125I] Iomazenil in experimental epileptogenesisI. The rat kainate model of temporal lobe epilepsy

Cited by 3 publications

References 0 publications

Neuroimaging in animal models of epilepsy

Neuroimaging in animal models of epilepsy

Central‐type Benzodiazepine Receptors and Epileptogenesis: Basic Mechanisms and Clinical Validity

Hippocampal Stem Cell Grafting-Mediated Recovery of Injured Hippocampus in the Rat Model of Temporal Lobe Epilepsy

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