Learning Behavior of Rats Given Low Level 

 X-lrradiation in Utero on Various Gestation 



Days* 



Sylvan J. Kaplan f 

 Texas Technological College, Lubbock, Texas 



These experiments were done to determine manifestations of behavioral 

 aberration as related to age of subject at time of irradiation, age of irradi- 

 ated subject at time of testing, magnitude of dose, and type of instrument 

 capable of measuring the observed phenomena. 



Since much literature exists confirming the fact that x-radiation delivered 

 in utero has an adverse effect on subsequent learning ability of the exposed 

 rat (Furchtgott et al., 1958; Levinson, 1952; Tait et al., 1960), this study 

 is concentrated on portions of the gestation period and levels of radiation 

 dosages not reported nor extensively employed in animal learning studies. 



Two dispai'ate, but related, experiments will be presented, one on age at 

 time of maze learning and another on age at time of conditioning and 

 extinction. 



Subjects 



Of 114 albino rats, bred in and shipped from Columbia University de- 

 partment of radiology laboratoiy, 43 were approximately 400 days old and 

 71 were approximately 90 days old at the beginning of experiment one. 

 At completion of the maze experiment, 59 rats to be used in the conditioning- 

 extinction experiment were randomly selected from the respective groups. 

 They were 540 and 120 days old, respectively, by the start of experiment 

 two. Numbers of subjects per subgroup, experimental task, and radiation 

 condition for each are indicated in Table I. All subjects were naive to 

 psychologic experimentation at the start of the study. 



* Supported by the Atomic Energy Commission. 



t Roberts Rugh, Columbia University, conducted the irradiation of all subjects; 

 his work was aided in part by a U.S. Public Health grant. The following colleagues 

 and assistants worked in the project obtaining data: Barbara Brodigan, Shirley Clark, 

 Gerald Garrett, Robert Graham, Robert Hall, Allen Holmes, Gale Howell, Vincent 

 Luchsinger, W. H. Melching, and Paul Thomas. 



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