AVERSIVE CONDITIONING AND GLUCOSE LEVELS IN DIABETIC AND NON-DIABETIC MICE: EFFECTS OF STRESS AND DIET
The research explored the effects of three types of stress conditioning and two types of diet on learning and serum glucose levels in mice genetically determined to be either diabetic or non-diabetic. Ninety diabetic and 90 non-diabetic animals received either a high-protein or standard laboratory diet. From the four resultant cells (n = 45), mice were randomly assigned to one of three treatments. In the escapable shock condition, mice received a 0.2 mA tail shock which they could terminate by rotating a wheel. The circuitry for the inescapable shock condition was "yoked" to the escapable condition so that mice received the same intensity and duration of shock, but wheel rotation had no consequence. Control mice received no shock during the conditioning phase. The testing phase which followed conditioning consisted of a behavioral assay (avoidance learning) and a physiological assay (serum glucose levels).^ Diabetic mice demonstrated significant performance deficits in both behavioral measures, i.e., escape and avoidance acquisition. Further, glucose levels among diabetics were significantly higher than those of non-diabetics, regardless of diet received or stress condition experienced. Type of diet received significantly altered glucose levels, especially among diabetics, as evidenced by the genotype x diet interaction effect obtained for the glucose variable (p < .05). The interaction between the measures of genotype and diet was significant also for the avoidance measure. However, this interaction was contrary to expectations, since it was the non-diabetic mice maintained on the high-protein diet who evidenced an improvement in avoidance acquisition. Type of stress encountered during conditioning did not significantly impact subsequent acquisition of the avoidance response or glucose levels.^ The results confirm the proposition that diabetes impedes learning among mice and suggest that the impairment suffered by diabetic mice was related, at least in part, to excessively high levels of serum glucose. Although the specialized diet lowered glucose levels substantially among the diabetics, their blood sugars remained elevated in comparison to normal mice. The findings are discussed in view of the limitations imposed by the physical and physiological characteristics of diabetic mice. Suggestions for future research to alleviate these and other difficulties are enumerated. ^
CARLSON, JANET F, "AVERSIVE CONDITIONING AND GLUCOSE LEVELS IN DIABETIC AND NON-DIABETIC MICE: EFFECTS OF STRESS AND DIET" (1987). ETD Collection for Fordham University. AAI8714575.