Food-motivated behavior in rats with cortico-basomedial amygdala damage.

Abstract

Twelve rats with amygdala damage (CBM) and 20 sham-operated controls were tested in several food-related situations. The CBM rats showed a longer latency to eat than controls in a novel environment due to more pronounced exploration. In the competition for food, CBM rats lost 85% of encounters with controls. Immediately after the contest, when allowed to eat singly, CBM rats displayed a higher persistence of alimentary responses to an emptied cup than did controls, presumably because they experienced more losses in the food competition. Both groups were equally able to overcome obstacles on the way to food, which suggests similar alimentary motivation. The only direct indication of a lowered responsiveness to hunger in CBM rats was 24-hr-fasting-induced hypophagia. The results of this study indicate the involvement of the cortico-basomedial amygdaloid region in the control of relations between alimentary and other motivations. The contribution of eventual changes of food motivation in the postoperative alteration of this balance is discussed.

The effects of excitotoxic lesions of the basolateral amygdala on the acquisition of heroin-seeking behaviour in rats

“…Although some studies have reported disinhibition of both instrumental and unconditioned behaviour following electrolytic amygdala lesions (Pellegrino 1968;McDonough and Manning 1979;Lukaszewska et al 1984), this is not generally the case (see Sarter and Markowitsch 1985 for a review), especially after excitotoxic lesions such as those used here (Everitt et al 1987Cador et al 1989;Burns et al 1993;Parkinson et al 2000). Indeed, the BLA lesioned rats in the present study did not show increased responding for heroin under a continuous reinforcement schedule.…”

Progranulin haploinsufficiency causes biphasic social dominance abnormalities in the tube test

“…Additional data from rodents indicate that both brain regions affect dominance behavior. While the results vary with experimental paradigm, lesions of the amygdala generally reduce dominance and aggression in rodents (Bunnell ; Lukaszewska et al ; Miczek et al ; Vochteloo & Koolhaas ). However, it is difficult to conclusively tie increased basomedial amygdala dendritic arbors to increased tube test dominance, as the relationship between amygdala activity and dominance behavior is complex given the anatomic and cellular heterogeneity of the amygdala.…”

The Neural Circuit Architecture of Social Hierarchy in Rodents and Primates

“…These correlative studies were complemented by lesion studies, but the results are hard to conciliate. In fact, previously dominant monkeys were shown to lose social status and acquire subordinate behavior upon lesions in the AMY (Rosvold et al, 1954 ), and rats harboring AMY damage lose 85% of the encounters when competing for food against controls (Lukaszewska et al, 1984 ), suggesting that AMY lesions decrease dominance. Contrary to these, selective ablation of the AMY was found to increase confidence in social interactions (Emery et al, 2001 ) and increase dominant posture in rhesus monkeys (Machado and Bachevalier, 2006 ).…”