[Intersex and interspecies differences in sucrose consumption by rats with various behavioral strategies].

Sucrose consumption by male and female rats during active avoidance acquisition was measured in two rat strains: KLA (Koltushi low avoidance) and KHA (Koltushi high avoidance) selected for divergent performance in a shuttlebox. Under resting condition, there were no interstrain difference in sucrose consumption by males, but KHA females consumed significantly less sucrose than KLA females. Active avoidance acquisition during five consecutive days decreased sucrose consumption in KLA males and did not change sucrose consumption in KHA males. Within a week after exposure to the stress, the sucrose consumption by KLA males returned to its normal values, and KHA males consumed significantly more sucrose. The active avoidance conditioning did not affect sucrose consumption in females of both strains. Substitution of 32% solution for 4% produced on the first day a sharp decrease in sucrose consumption in males of both strains, while females sharply increased consumption of the diluted solution over the next four days of observation. During this time, males returned to consumption of the same volume of the solution despite its decreased concentration. The findings suggest that the exposure to the escapable stress induces the negative affect only in KLA males.