LESION OF CENTRAL NUCLEUS OF AMYGDALA PROMOTES FAT GAIN WITHOUT PREVENTING EFFECT OF EXERCISE ON ENERGY-BALANCE

Male Wistar rats with intact or lesioned central nucleus of amygdala ( CeA) were kept at rest or subjected to a treadmill running program for 21 consecutive days. Food intake and body weight were monitored throu ghout the exercise training program. At the end of the program, rats w ere killed and their carcasses processed for analysis of the contents in energy, fat, and protein. Exercise and CeA lesions induced opposite effects on energy balance; exercise delayed gains in body energy and fat, whereas CeA lesions promoted them. Total energy intake was lower in exercised rats than in sedentary ones over the 12 and 24 h that fol lowed exercise. Food intake was higher in lesioned rats than in intact animals over the second half of the 12-h period that followed exercis e. There was no interaction effect of exercise and CeA lesions on ener gy balance and intake and on body composition. Plasma levels of adreno corticotropin hormone and corticosterone were higher in exercised rats than in sedentary ones, but there was no difference between lesioned and intact rats. This study, as well as confirming the effect of exerc ise on energy balance, indicates that CeA lesions may promote energy d eposition in rats. Above all the present results provide evidence that CeA does not represent a necessary neuroanatomic structure in the eff ect of exercise on energy balance.