Ionizing radiation alters neuronal excitability in hippocampal slices of the guinea pig
To investigate the effects of ionizing radiation on an isolated neuronal network without complicating systemic factors, slices of hippocampus from the guinea pig were isolated and studied in vitro. Slices were irradiated with a /sup 60/Co source and compared to paired, sham-irradiated controls. Electrophysiological activity in the CA 1 population of pyramidal cells was evoked by stimulation of the stratum radiatum. Analysis of the somatic and dendritic responses suggested sites of radiation damage. Orthodromically evoked activity was significantly decreased in slices receiving greater than 75 Gy gamma radiation. The effects were dose and dose-rate dependent. At 20 Gy/min, doses of 50 Gy and greater produced synaptic impairment while doses of 75 Gy and greater also produced postsynaptic damage (i.e., the ability of the synaptic response to generate an action potential). A lower dose rate, 5 Gy/min, reduced the sensitivity of synaptic damage to radiation exposure; synaptic impairment required a dose of 100 Gy or greater at the lower dose rate. In contrast, postsynaptic damage was not sensitive to dose rate. This study demonstrates that ionizing radiation can directly affect the integrated functional activity of neurons.
- Research Organization:
- Armed Forces Radiobiology Research Institute, Bethesda, MD
- OSTI ID:
- 5468048
- Journal Information:
- Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 112:3; ISSN RAREA
- Country of Publication:
- United States
- Language:
- English
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Cells
& Tissue Culture
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BODY
BRAIN
CENTRAL NERVOUS SYSTEM
COBALT 60
COBALT ISOTOPES
DOSE-RESPONSE RELATIONSHIPS
ELECTROMAGNETIC RADIATION
ELECTROPHYSIOLOGY
GAMMA RADIATION
GUINEA PIGS
HIPPOCAMPUS
IN VITRO
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IONIZING RADIATIONS
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MAMMALS
MINUTES LIVING RADIOISOTOPES
NERVE CELLS
NERVOUS SYSTEM
NUCLEI
ODD-ODD NUCLEI
ORGANS
PHYSIOLOGY
RADIATION EFFECTS
RADIATIONS
RADIOISOTOPES
RODENTS
SOMATIC CELLS
VERTEBRATES
YEARS LIVING RADIOISOTOPES