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United States Department of Agriculture

Agricultural Research Service

Title: Long-Term Changes in Amphetamine-Induced Reinforcement and Aversion in Rats Following Exposure to 56fe Particles

Authors
item Rabin, Bernard - UNIV MARYLANF BALTIMORE
item Joseph, James
item Shukitt-Hale, Barbara

Submitted to: Advances in Space Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 31, 2002
Publication Date: January 31, 2003
Citation: Rabin, B.M., Joseph, J.A., and Shukitt-Hale, B. Long-term changes in amphetamine-induced reinforcement and aversion in rats following exposure to 56Fe particles. Adv. Space Res. 2003, 31: 127-133.

Interpretive Summary: Exposing rats to radiation particles of high energy and charge disrupts the functioning of one system in the brain and the behaviors mediated by this system. Two of these behaviors include amphetamine-induced reinforcement, measured using the conditioned place preference procedure, and amphetamine-induced aversion, measured using the conditioned taste aversion; these adverse behavioral effects are similar to those seen in aged animals. Previous research had shown that exposing rats to radiation particles disrupts taste aversion 3 days following exposure; however, radiation enhanced taste aversion 112 days following exposure. The present experiment evaluated taste aversion learning 154 days following exposure to radiation to further explore these effects. Also examined were the effects of radiation exposure on the formation of an amphetamine-induced conditioned place preference 3, 7, and 16 weeks after irradiation. The taste aversion results did not confirm the apparent enhancement of the amphetamine-induced aversion observed in the prior experiment at the longer time point. However, exposure to radiation particles prevented the acquisition of an amphetamine-induced place preference at all three time intervals. The results show that exposure to radiation can produce long-term changes in behavioral functioning.

Technical Abstract: Exposing rats to heavy particles produces alterations in the functioning of dopaminergic neurons and in the behaviors that depend upon the integrity of the dopaminergic system. Two of these dopamine-dependent behaviors include amphetamine-induced reinforcement, measured using the conditioned place preference procedure, and amphetamine-induced aversion, measured using the conditioned taste aversion. Previous research had shown that exposing rats to 1.0 Gy of 1 GeV/n 56Fe particles produced a disruption of an amphetamine-induced taste aversion 3 days following exposure, but produced an apparent enhancement of the aversion 112 days following exposure. The present experiments were designed to provide a further evaluation of these results by examining taste aversion learning 154 days following exposure to 1.0 Gy 56Fe particles and to establish the convergent validity of the taste aversion results by looking at the effects of exposure on the establishment of an amphetamine-induced conditioned place preference 3, 7, and 16 weeks following irradiation. The taste aversion results failed to confirm the apparent enhancement of the amphetamine-induced CTA observed in the prior experiment. However, exposure to 56Fe particles prevented the acquisition of an amphetamine-induced place preference at all three time intervals. The results are interpreted as indicating that exposure to heavy particles can produce long-term changes in behavioral functioning.

Last Modified: 10/1/2014