Effects of sublethal doses of ionizing radiation on schedule-controlled performance in rats

Journal Article · Mon Aug 01 00:00:00 EDT 1988 · Pharmacol., Biochem. Behav.; (United States)

DOI:https://doi.org/10.1016/0091-3057(88)90133-5· OSTI ID:6324237

Mele, P C; Franz, C G; Harrison, J R

Male rats responded under a fixed-ratio (FR) 50 or a fixed-interval (FI) 120 sec schedule of milk delivery. Separate groups were acutely exposed to 0.5, 1.5, 4.5 or 0 (FI only) Gray (Gy) of cobalt-60 gamma radiation 3 times at 43-day intervals. All rats received an acute dose of 6.5 Gy 64 days after the last of these exposures. One-half and 1.5 Gy did not alter FR or FI performance significantly. After 4.5 Gy, no observable changes in performance occurred within 1 hr of exposure. Maximal reductions in FR response rates occurred 24 hr after exposure and recovery followed over the subsequent 72 hr. Postreinforcement pause was increased and running response rate was decreased by 4.5 Gy. Similar effects were found after each 4.5 Gy exposure. In contrast, FI performance (overall response rate, postreinforcement pause, running response rate, index of curvature) was not altered reliably by 4.5 Gy. Both FR and FI response rates were reduced by 6.5 Gy beginning 24 hr after exposure; FR rates tended to be reduced more than FI rates 24-72 hr after exposure. Response rates under both schedules recovered gradually over 7 weeks. The behavioral effects of 6.5 Gy did not vary as a function of irradiation history. In contrast, irradiation history affected survival in that 4/9 rats previously exposed to 4.5 Gy died during weeks 4-5 after 6.5 Gy, whereas there were no deaths in the rats previously exposed to lower doses. Radiogenic disruption of operant performance was dose-related, reversible, noncumulative and dependent on the schedule of reinforcement.

• Research Organization: Armed Forces Radiobiology Research Institute, Bethesda, MD (USA)
• OSTI ID: 6324237
• Journal Information: Pharmacol., Biochem. Behav.; (United States), Journal Name: Pharmacol., Biochem. Behav.; (United States) Vol. 30:4; ISSN PBBHA
• 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.
ACUTE EXPOSURE
ACUTE IRRADIATION
ANIMALS
BEHAVIOR
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
COBALT 60
COBALT ISOTOPES
DOSE-RESPONSE RELATIONSHIPS
ELECTROMAGNETIC RADIATION
FRACTIONATED IRRADIATION
GAMMA RADIATION
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IONIZING RADIATIONS
IRRADIATION
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MAMMALS
MINUTES LIVING RADIOISOTOPES
NUCLEI
ODD-ODD NUCLEI
RADIATION EFFECTS
RADIATIONS
RADIOISOTOPES
RATS
RODENTS
SUBLETHAL IRRADIATION
VERTEBRATES
YEARS LIVING RADIOISOTOPES