684 



DONALD J. KIMELDORF 



TABLE II 



Manipulation and Confinement Stimuli Complex * 



Previous exposure history 



Postir radiation 



sham exposure test 



food and water consumption 



Radiation + food and water 

 Radiation + food only 

 Radiation only 

 Sham irradiation -|- food and water 



decline 

 decline 

 normal 

 normal 



* Exposure pattern: gamma radiation, 1-9 exposures with 75 r per exposure at 9.4 r per hr. 



and the direction of consumption in a postirradiation sham exposure test. 

 Food and water consumption in the sham exposure test was decreased in the 

 groups which had previously experienced food and water consumption 

 during radiation exposure. When animals were given only food during ir- 

 radiation, the consumption of both food and water was decreased in the 

 subsequent sham exposure test. In contrast, animals without food and water 

 during periodic irradiation exhibited no inhibition of consumption during 

 the sham exposure test. Littermate controls which had been periodically 

 sham irradiated prior to the sham exposure test maintained or increased 

 food and water consumption during the test. 



It was concluded that manipulation and confinement to a radiation 

 chamber can serve as a conditioned stimulus complex to produce a reduction 

 in consummatory behavior, provided the animals had previously consumed 

 food or water, or both, during radiation exposure in the same situation. The 

 approach, however, was awkward, principally because of the difficulties in 

 specifying the important variables involved in the conditioned stimuli of 

 manipulation and confinement. 



To facilitate further study, a distinctive taste cue was utilized in conjunc- 

 tion with radiation exposure, and the animal was subsequently tested for the 

 presence of a conditioned response towards the taste cue. Saccharin flavored 

 water was selected as the discrimlnable taste stimulus, since it is normally 

 preferred to tap water by the rat and could be manipulated in a convenient 

 manner. 



Preirradiation and postirradiation tests of saccharin preference were made 

 on animals which received either saccharin or water during radiation ex- 

 posure, with saccharin flavored water and tap water available simultane- 

 ously. In terms of preference, the consumption of saccharin flavored water 

 normally constitutes more than 75% of the total fluid intake. Table III 

 describes several conditions investigated with respect to radiation exposure 

 and saccharin preference. It was found (Garcia et al., 1955) that animals 



