RESEARCH FOCUS ON COMPULSIVE BEHAVIOUR IN ANIMALS: An animal model of compulsive food‐taking behaviour

Abstract

The increase in the incidence of obesity and eating disorders has promoted research aimed at understanding the aetiology of abnormal eating behaviours. Apart from metabolic factors, obesity is caused by overeating. Clinical reports have led to the suggestion that some individuals may develop addictive-like behaviours when consuming palatable foods, and compulsive eating plays a similar dominant role in obesity as compulsive drug taking does in drug addiction. The progress made in the development of treatment strategies for obesity is limited, in part, because the physiological and neurological causes and consequences of compulsive eating behaviour are not clearly understood and cannot readily be studied in human subjects. We have developed experimental approaches that reflect the functioning of the components of eating control, including compulsive food taking in rats. Rats that are given free choice between standard chow and a palatable, chocolate-containing 'Cafeteria Diet' (CD) develop distinct signs of compulsive food taking that appear at an early stage. These include the inability to adapt intake behaviour in periods of limited or bitter-tasting CD access, continued food intake during resting phases and changes in fine structure of feeding (duration, distribution and recurrence of feeding bouts). The model will help examine the neurobiological underpinnings of compulsive food seeking and food taking and provides a possibility to study the effects of novel anti-obesity compounds on compulsive eating and other components of food-taking behaviour in detail. For future use of genetic models, the possibility of a transfer to a mouse was discussed.

Intermittent access to sucrose increases sucrose-licking activity and attenuates restraint stress-induced activation of the lateral septum

“…Although unrestricted access to palatable food may decrease the stressinduced activation of the HPA axis, the intermittent consumption of palatable food may exacerbate some components of the eating behavior and lead to repeated excessive intake of palatable food with affective withdrawal-like states after the removal of palatable components from the diets (4,14,20,23,38). Although there is evidence that intermittent access to palatable food affects meal pattern by extending food intake during the resting phase and altering the fine structure of feeding (44), there are no explicit data showing the pattern of sucrose-licking activity in rats maintained on intermittent access to sucrose without or in combination with food restriction.…”

Antagonism of Sigma-1 Receptors Blocks Compulsive-Like Eating

“…An increased time spent in this compartment, as compared to control conditions, resulting from the presence of the highly palatable diet, was operationalized as 'risk-taking behavior' (Colorado et al, 2006;Teegarden and Bale, 2007). Moreover, under normal, control conditions, eating behavior is typically suppressed when a rat faces adverse circumstances; a significant increase in food intake in spite of the adverse conditions, as compared to control conditions, was operationalized as a construct of 'compulsive-like eating' (Belin et al, 2008;Davis et al, 2010;Heyne et al, 2009;Hopf et al, 2010;Johnson and Kenny, 2010 …”

Dietary Factors Affect Food Reward and Motivation to Eat

“…This reduction in D 2 receptors was not only accompanied by deficits in reward sensitivity but also by compulsive food-seeking behavior in the light of adversity [90], a crucial criterion for the diagnosis of substance abuse [94]. Compulsive overconsumption of cafeteria food was also noted by Heyene and colleagues [95]. In their model, animals exposed to ad-libitum cafeteria diet for 11 weeks showed inflexibility in increasing their chow intake coupled with depression of motor activity during limited access to cafeteria diet.…”