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ARS Home » Northeast Area » Boston, Massachusetts » Jean Mayer Human Nutrition Research Center On Aging » Research » Publications at this Location » Publication #172133

Title: A LONGITUDINAL STUDY OF OPERANT RESPONDING IN RATS IRRADIATED AT TWO MONTHS OF AGE

Author
item RABIN, BERNARD - UMBC, DEPT PSYCHOLOGY
item Joseph, James
item Shukitt-Hale, Barbara

Submitted to: Radiation Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/30/2004
Publication Date: 9/5/2005
Citation: Rabin, B.M., Joseph, J.A., Shukitt Hale, B. 2005. A longitudinal study of operant responding in rats irradiated at two months of age. Radiation Research. 164:552-555.

Interpretive Summary: Previous work has shown that exposure to heavy particles (such as iron particles) produces cognitive deficits in young animals that are characteristic of much older animals. Two-month old rats were exposed to heavy particles (iron particles, at levels of 1.0, 1.5, 2.0 Gy; 1 GeV/n). They were tested on the performance of an ascending fixed-ratio operant task (bar pressing for food reward) at 3, 7, 11, and 15 months following irradiation. At three months following exposure, only the rats exposed to 2.0 Gy of iron particles showed a significant disruption of performance compared to control (0 Gy) rats. When tested 7, 11, and 15 months after exposure, all radiated groups showed significantly poor performance than the controls. These results are consistent with previous research showing that exposure to heavy particles produces accelerated aging and suggest that there is an interaction between irradiation and age such that iron-induced performance deficits can develop months after exposure.

Technical Abstract: Two-month old rats were exposed to 56Fe particles (1.0, 1.5, 2.0 Gy; 1 GeV/n). They were tested on the performance of an ascending fixed-ratio operant task (bar pressing for food reward) at 3, 7, 11, and 15 months following irradiation. At three months following exposure, only the rats exposed to 2.0 Gy of 56Fe particles showed a significant disruption of performance compared to control (0 Gy) rats. When tested 7, 11, and 15 months after exposure, all radiated groups showed significantly poor performance than the controls. These results are consistent with previous research showing that exposure to heavy particles produces accelerated aging and suggest that there is an interaction between irradiation and age such that 56Fe-induced performance deficits can develop months after exposure.