Enhanced Excitability Induced by Ionizing Radiation in the Kindled Rat

Jenrow, Kenneth A.; Ratkewicz, Alexander; Elisevich, Kost

doi:10.1006/exnr.2000.7616

Cited by 10 publications

(5 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, SOs mediated by overstimulation of NMDAreceptors (40) were shown to be further modulated by adrenergic inputs (85). These inputs may also be sensitive to radiation and need to be investigated (80,86).…”

Section: Discussionmentioning

confidence: 99%

A Single Low Dose of Proton Radiation Induces Long-Term Behavioral and Electrophysiological Changes in Mice

Bellone¹,

Rudobeck

Hartman³

et al. 2015

Radiation Research

View full text Add to dashboard Cite

Astronauts traveling outside Earth's magnetosphere risk exposure to charged particle radiation that may cause neurophysiological changes and behavioral deficits. Although proton particles comprise a large portion of the space radiation environment, little has been published on the effects of low-dose proton radiation on central nervous system function. In the current study, we irradiated young male mice with 0.5 Gy 150 MeV protons and assessed the effects on behavior and hippocampal neurophysiology. Spatial learning ability, a sensitive behavioral marker of hippocampal damage, was assessed using the water maze and Barnes maze before irradiation and repeatedly 3 and 6 months after irradiation. Evoked field excitatory postsynaptic potentials (fEPSPs) and population spikes, long-term potentiation (LTP) and spontaneous oscillations (SOs) triggered by incubation with Mg(2+)-free media (reflecting interictal epileptiform activity) were assessed 9 months after irradiation in vitro in hippocampal slice preparations. Irradiated mice exhibited impaired reversal learning in the water maze compared to control mice 6 months after irradiation. Proton radiation did not affect LTP, but significantly increased fEPSP slopes and reduced the incidence of SOs 9 months after irradiation. These findings suggest that a single exposure to low-dose proton radiation can increase synaptic excitability and suppress the propensity for epileptiform activity. Such findings of functional alterations in the irradiated mouse hippocampus have implications for extended manned space missions planned in the near future.

show abstract

Section: Discussionmentioning

confidence: 99%

A Single Low Dose of Proton Radiation Induces Long-Term Behavioral and Electrophysiological Changes in Mice

Bellone¹,

Rudobeck

Hartman³

et al. 2015

Radiation Research

View full text Add to dashboard Cite

show abstract

“…A high radiation dose of 25 Gy, applied focally to the amygdala prior to kindling, does not affect stimulation threshold to evoke a generalized seizure, but causes an increased tendency for seizure activity to propagate into brain stem circuits. However, if radiation is applied later, when the kindled state is already established, the tendency of seizures to spread into brains stem circuits is decreased (Jenrow et al, 2001, 2006). Next to the fact that the radiation is applied much more focal in these studies, the authors also use a radiation dose that is much higher than in our study.…”

Section: Discussionmentioning

confidence: 99%

“…Other studies have investigated the effect of radiation on the course of amygdala kindling epileptogenesis (Jenrow et al, 2001, 2006). A high radiation dose of 25 Gy, applied focally to the amygdala prior to kindling, does not affect stimulation threshold to evoke a generalized seizure, but causes an increased tendency for seizure activity to propagate into brain stem circuits.…”

Section: Discussionmentioning

confidence: 99%

Radiation of the Rat Brain Suppresses Seizure‐Induced Neurogenesis and Transiently Enhances Excitability during Kindling Acquisition

et al. 2007

View full text Add to dashboard Cite

Summary:Purpose: Adult hippocampal neurogenesis is enhanced in several models for temporal lobe epilepsy (TLE). In this study, we used low-dose whole brain radiation to suppress hippocampal neurogenesis and then studied the effect of this treatment on epileptogenesis in a kindling model for TLE.Methods: Half of the rats were exposed to a radiation dose of 8 Gy one day before the initiation of a rapid kindling protocol. Afterdischarge threshold (ADT), afterdischarge duration (ADD), clinical seizure severity, and inflammation were compared between groups. On the first and third day after radiation, rats were injected with 5 -bromo-2 -deoxyuridine (BrdU) to evaluate neurogenesis. Seven and 21 days after radiation, numbers of doublecortin (DCX) positive neuroblasts in subgranular zone and granule cell layer were compared between groups.Results: We showed that radiation significantly suppressed neurogenesis and neuroblast production during kindling acquisition. Radiation prevented an increase in ADT that became significantly lower in radiated rats. On the third and fourth kindling acquisition day radiated rats developed more severe seizures more rapidly, which resulted in a significantly higher mean severity score on these days. Differences in ADD could not be demonstrated.Discussion: Our results demonstrate that brain radiation with a relatively low dose effectively suppressed the generation of new granule cells and transiently enhanced excitability during kindling acquisition. Although seizure-induced neurogenesis was lower in the radiated rats we could not detect a strong effect on the final establishment of the permanent fully kindled state, which argues against a prominent role of seizure-induced neurogenesis in epileptogenesis.

show abstract

“…Whether lesionally-associated or not, there is much yet to be understood regarding the radiobiology of the effect upon the epileptic condition [136][137][138].…”

Section: Effect Of Ionizing Radiationmentioning

confidence: 99%

Glioma-Associated Epilepsy

Elisevich¹

2013

Clinical Management and Evolving Novel Therapeutic Strategies for Patients With Brain Tumors

View full text Add to dashboard Cite

Enhanced Excitability Induced by Ionizing Radiation in the Kindled Rat

Cited by 10 publications

References 56 publications

A Single Low Dose of Proton Radiation Induces Long-Term Behavioral and Electrophysiological Changes in Mice

A Single Low Dose of Proton Radiation Induces Long-Term Behavioral and Electrophysiological Changes in Mice

Radiation of the Rat Brain Suppresses Seizure‐Induced Neurogenesis and Transiently Enhances Excitability during Kindling Acquisition

Glioma-Associated Epilepsy

Contact Info

Product

Resources

About