Neurobiology of food intake in health and disease

Abstract

Under normal conditions, food intake and energy expenditure are balanced by a homeostatic system that maintains stability of body fat content over time. However, this homeostatic system can be overridden by the activation of ‘emergency response circuits’ that mediate feeding responses to emergent or stressful stimuli. Inhibition of these circuits is therefore permissive for normal energy homeostasis to occur, and their chronic activation can cause profound, even life-threatening, changes in body fat mass. This Review highlights how the interplay between homeostatic and emergency feeding circuits influences the biologically defended level of body weight under physiological and pathophysiological conditions.

The role of leptin in diabetes: metabolic effects

“…uDM is characterised by hyperphagia, hyperglucagonaemia and hypercorticosteronaemia, and each of these is thought to increase glucose production and promote hyperglycaemia [23]. At the same time, the hypothalamicpituitary-thyroid (HPT) axis is inhibited and, similar to other conditions of leptin deficiency (ob/ob mice and fasting), each of these abnormalities is corrected by leptin treatment [24].…”

Central nervous insulin administration before nocturnal sleep decreases breakfast intake in healthy young and elderly subjects

“…Considering that hunger ratings were comparable between conditions, it may be concluded that intranasal insulin did not affect hunger motivation, but rather acted via satiating factors that contribute to the termination of a meal. We did not find discernible treatment-induced changes in ghrelin and leptin, two hormones of paramount relevance for food intake control (Morton et al, 2014). A mild insulininduced decrease in plasma glucose concentration apparently was restricted to the young participants although our study was not designed to detect respective differences between age groups.…”

“…Eating behavior is tightly regulated by central nervous circuitries that receive hormonal feedback on body fat stores and nutritional status from the body periphery (Morton et al, 2014). In addition to the adipocyte-derived hormone leptin, insulin is one of the major peripheral signals that contribute to the central nervous control of ingestive behavior.…”

Syndrome de Bardet-Biedl : cils et obésité

“…Il soupçonna une dérégulation hormonale au niveau hypothalamique [38]. L'hypothalamus apparaît comme un centre intégrateur des signaux périphériques contrôlant l'équilibre entre la prise alimentaire et la dépense énergétique [39] (voir Figure 1A). Il possède des neurones ciliés exprimant les protéines BBS, et est ciliopathies font partie d'une classe émergente de maladies géné-tiques rares, qui affectent le bon fonctionnement du cil primaire et pour lesquelles il existe une grande variabilité phénotypique (voir Tableau I) [11].…”