STRESS SELECTIVELY REDUCES SUGAR PLUS SACCHARIN MIXTURE INTAKE BUT INCREASES PROPORTION OF CALORIES CONSUMED AS SUGAR BY RATS

Exposure to unsignaled, inescapable tailshock reduces intake of quinin e- or saccharin-adulterated water but increases intake of dilute sucro se solution. This pattern suggests that stress may reduce consumption of quinine and saccharin by enhancing their aversive taste properties. The present study provided additional support for this interpretation : Stress reduced intake of a saccharin-adulterated solution of glucose (Experiment 1) or sucrose (Experiment 2) but not of unadulterated sug ar solutions. Stress also reduced body weight and total calorie intake , and increased selection of calories in the form of sugar (Experiment 2). These findings are inconsistent with the generalized ''anhedonia' ' concept prominent in the literature on stress-induced changes in ing estion and other motivated behaviors. The selectivity of tailshock's e ffects on ingestion encourages further development of an energy-regula tion model of stress (the regulatory shift hypothesis), including expl oration of the roles that macronutrient accessibility and sugars' stre ss-reducing, reinforcing properties might play in the behavior of stre ssed rats.