Effects of ionizing radiation on fixed-ratio escape performance in rats

Journal Article · Sun Jul 01 00:00:00 EDT 1990 · Neurotoxicology and Teratology; (USA)

DOI:https://doi.org/10.1016/0892-0362(90)90056-I· OSTI ID:6509162

Mele, P C; Franz, C G; Harrison, J R ^[1]

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1. Armed Forces Radiobiology Research Institute, Bethesda, MD (USA)

Adult male rats pressed a lever to terminate scrambled footshock according to a fixed-ratio 20 schedule (FR escape). Separate groups of rats received a single whole-body exposure to 4.5 or 7.5 Gray (Gy) of gamma photon radiation or were sham irradiated. The first postirradiation test session began 5 min after the end of the irradiation. The 4.5 Gy dose failed to produce any significant changes in performance over six weeks of testing after exposure. In contrast, response rates after irradiation with 7.5 Gy were decreased over the first four weeks postexposure. Reductions in response rate were due to both an increase in the latency to the first response of a ratio and to a reduction in running response rate. Performance recovered to preirradiation control levels during weeks 5-6 after exposure to 7.5 Gy. Body weights were decreased dose-dependently to a minimum of 91% of preirradiation control values during the third week after exposure to 7.5 Gy. A significant positive correlation existed for changes in the weekly average response rates and body weights at this dose. When a total dose of 7.5 Gy was delivered as 1.5 Gy per day for five consecutive days (dose fractionation), there were no significant changes in performance over eight weeks of testing although reversible decreases in response rates occurred in three of six rats. By comparison with previous studies these results demonstrate that FR escape performance may provide a more sensitive index of radiation-induced behavioral disruption than performance maintained by several other schedules of negative reinforcement.

• OSTI ID: 6509162
• Journal Information: Neurotoxicology and Teratology; (USA), Journal Name: Neurotoxicology and Teratology; (USA) Vol. 12:4; ISSN 0892-0362; ISSN NETEE
• Country of Publication: United States
• Language: English

Related Subjects

560152* -- Radiation Effects on Animals-- Animals
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BEHAVIOR
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
DOSE-RESPONSE RELATIONSHIPS
DOSES
ELECTROMAGNETIC RADIATION
EXTERNAL IRRADIATION
FRACTIONATED IRRADIATION
GAMMA RADIATION
IONIZING RADIATIONS
IRRADIATION
MAMMALS
RADIATION DOSES
RADIATION EFFECTS
RADIATIONS
RATS
RODENTS
VERTEBRATES
WHOLE-BODY IRRADIATION