Based on this mounting evidence, the aim of the present study was to knock down GK expression in tanycytes and evaluate the effects of GK suppression on feeding behavior. For this purpose, we generated a GK shRNA-containing adenovirus. Building on the success of previous studies from our laboratory demonstrating the inhibition of hypothalamic MCT1 mRNA expression using adenovirus-mediated transduction of a shRNA into the 3V and its effects on food intake, we focused on the use of this experimental tool in the present study29. We demonstrated that the adenoviral vectors selectively and effectively transduced tanycytes from the basal wall of the 3V, which is similar to Xu et al.35 and Elizondo et al.29. Additionally, we confirmed that GK mRNA expression was inhibited by 75% with respect to the control. Interestingly, we observed that GK knockdown increased food intake and altered feeding behavior, which is in accordance with a previous study showing that 4V injection of alloxan provokes an increase in food intake36. Alloxan is a β-cytotoxic toxic glucose analogue and is commonly used for the development of animal model of Type-I Diabetes Mellitus37. Alloxan is rapidly taken up by the pancreatic β-cells through GLUT238. Subsequent studies showed alloxan injected into 3V but not 4V produced a decreased food intake and an altered glucoprivic response, which was accompanied by a massive loss of tanycytes and a decrease in orexigenic NPY23, which is related to the presence of GLUT2 in the tanycytes12. We could not assess whether the adenovirus reaches more distant brain regions. Further studies are required to analyze whether adenovirus-mediated GK suppression affects the dorsal vagal complex, another cerebral region with important functions as central glucosensing functions39, 40. Importantly, it has recently been described that neurons in the nucleus of the solitary tract respond to acutely altered glucose concentration with either increases or decreases in neural excitability and altered synaptic input24, 39, which are GK-dependent40.