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(56)Fe-particle radiation reduces neuronal output and attenuates lipopolysaccharide-induced inhibition of long-term potentiation in the mouse hippocampus.
- Source :
-
Radiation research [Radiat Res] 2008 May; Vol. 169 (5), pp. 523-30. - Publication Year :
- 2008
-
Abstract
- Exposure to space radiation consisting of high-energy charged (56)Fe particles represents a significant health risk for astronauts. (56)Fe-particle radiation affects the synaptic plasticity of the hippocampus and alters its response to the experimental immunological stressor lipopolysaccharide (LPS). We previously showed in mice that 1 month after exposure to (56)Fe-particle radiation, the LPS-induced inhibition of hippocampal long-term potentiation (LTP) was significantly attenuated, resulting in seemingly normal LTP. In the current study, we investigated this phenomenon further at longer times postirradiation. We exposed mice to accelerated iron particles ((56)Fe; 600 MeV/nucleon; 1, 2, 4 Gy; brain only), and 1, 3, 6 or 12 months postirradiation we administered LPS. Four hours after the intraperitoneal LPS injection, we prepared hippocampal slices to measure synaptic excitability and plasticity between CA3-CA1 neurons. In unexposed mice, we confirmed that LPS inhibited LTP at all times. However, in mice exposed to 2 Gy, the LPS-induced LTP inhibition was attenuated and reversed to control values. Such reversal was evident at 1 and 3 months but not 6 and 12 months postirradiation. In addition, at 6 and 12 months postirradiation, we observed inhibition of population spike (PS) amplitudes at 4 Gy that correlated with decrements in dendritic potentials, suggesting synaptic damage. Our data show that (56)Fe-particle radiation affects the response of the hippocampus to an immunological stressor and that the alterations progress over time.
- Subjects :
- Animals
Hippocampus cytology
Hippocampus physiology
Long-Term Potentiation drug effects
Male
Mice
Mice, Inbred C57BL
Synapses drug effects
Synapses radiation effects
Hippocampus drug effects
Hippocampus radiation effects
Iron
Lipopolysaccharides pharmacology
Long-Term Potentiation radiation effects
Neurons drug effects
Neurons radiation effects
Subjects
Details
- Language :
- English
- ISSN :
- 0033-7587
- Volume :
- 169
- Issue :
- 5
- Database :
- MEDLINE
- Journal :
- Radiation research
- Publication Type :
- Academic Journal
- Accession number :
- 18439042
- Full Text :
- https://doi.org/10.1667/RR1228.1