Olfactory bulbectomy impairs the feeding response to 2-deoxy-D-glucose in rats

An early study reported that, unlike sham-operated rats, rats made anosmic by olfactory bulbectomy (OBX) failed to compensate for the dilution of their diet with nonnutritive bulk by increasing their food intake. In the present study, the effects of a glucoprivic challenge, intraperitoneal-administered 350 mg/kg 2-deoxy-D-glucose (2-DG), on food intake were measured in OBX and sham-operated female rats. Sham-operated rats significantly increased their food intake, but in two separate experiments OBX rats displayed no increase in food intake during the first 2 h following administration. Blood glucose levels were nearly identical in both groups. Body weights and daily food intakes of OBX rats did not differ from the sham-operated controls throughout the studies. Bulbectomized rats also displayed a normal drinking response after an intraperitoneal injection of 1M hypertonic saline. Hypothalamic nuclei and the neural pathways mediating taste have been implicated in the feeding response to 2-DG. The present results suggest that olfactory input and olfactory neural pathways also mediate, at least in part, the feeding response to a glucoprivic challenge induced by intraperitoneal injection of 2-DG.