688 DONALD J. KIMELDORF 



TABLE V 

 Experimental Conditions and Saccharin Preference Behavior 



Test subject Postirradiation conditioned Minimum effective 



saccharin aversion exposure dose used 



Intact 



Ophthalmectomized 

 Hypophysectomized 

 Adrenalectomized 

 Head exposed * 

 Thorax exposed ' 

 Abdomen exposed * 

 Pelvis exposed * 



present 

 present 

 present 

 present 

 present 

 present 

 present 

 present 



gamma rays, 10 r 

 gamma rays, 30 r 

 x-rays, 60 r 

 x-rays, 60 r 

 x-rays, 252 r 

 x-rays, 252 r 

 x-rays, 54 r 

 x-rays, 252 r 



Collimated beam with % in. diameter. 



Andrews and Cameron (1960), on the basis of controlled ventilation experi- 

 ments, also concluded that it was unlikely that ozone or oxides of nitrogen 

 provided adequate olfactory cues for radiation avoidance in the mouse, and 

 they emphasized the relative importance of the dose rather than the duration 

 of exposure. Evidence that ionizing radiation causes sensations referable to 

 cutaneous receptor stimulation in mammals does not exist at the dose levels 

 employed with conditioning, although this possibility cannot be dismissed. 

 Saccharin aversion has been produced in hypophysectomized animals and 

 in adrenalectomized animals, indicating that drastic alterations in endocrine 

 state do not interfere with the conditioning process (Garcia and Kimeldorf, 

 1960b). In an attempt to define a critical site of action for radiation ex- 

 posure in the conditioning framework, a collimated x-ray beam was used to 

 study saccharin avoidance conditioning in rats with localized radiation 

 exposure of the head, thorax, abdomen, or pelvis. While the abdomen proved 

 to be the most sensitive exposure region, conditioning could be instigated by 

 exposure of other regions with higher doses (Garcia and Kimeldorf, 1960b) . 



The failure to detect a critical locus for exposure or a direct sensory 

 avenue essential to the behavior has led to a consideration of systemic re- 

 sponses to radiation which may serve as internal stimuli to motivate avoid- 

 ance behavior in the rat. 



Very few functional responses have been reported to occur at comparable 

 dose levels in mammals. Relevant information concerns only events which 

 occur during the conditioning phase, i.e., during a brief radiation exposure. 



Several criteria, including heart rate, respiration frequency, deep body 

 temperature, and aortic blood pressure, have been investigated in the 

 conscious rat during exposure (Hunt and Kimeldorf, 1960). The changes 

 observed (Kimeldorf and Hunt, 1958) were not coincident with ex- 



