Organisms do not make the decision to feel hungry, but they can decide to satisfy, or to not satisfy, hunger.Consuming foods then maintains energy balance and can favor rewarding effects related to motivation toobtain food (“wanting”), defining eating behavior. In this context, this chapter describes part of the neuralbasis of eating behavior, focusing on critical action of serotonin (5-hydroxytryptamine, 5-HT) 4 receptors(5-HT4Rs) under stressful conditions. We found that 5-HT4Rs, located in an adaptive-decisive system(voluntary nervous system), including the medial prefrontal cortex and the nucleus accumbens, may favorrewarding and antidepressant effects of restrictive food intake (anorexia-like behavior). Here, we describeexperimental procedures which have been associated in order to study a part of the neural bases underlyingfood intake following intracerebral infusion of pharmacological and nucleic treatments (siRNA, virus) infreely moving mice treated or not with a recreational drug of abuse (“ecstasy”). It includes the descriptionof a micropunch technique required for analyzing specific downstream molecular events (cAMP: FRET,pCREB: Western blot, mRNA: RQ-PCR, binding sites: radioautography). Our conclusion introduces thatprocesses within the voluntary nervous system (underlying decision, motivation) could be modified toprevail over a cerebral autonomous control (hypothalamus) of hunger, compromising survival. The5-HT4Rs could be targeted with antagonist/inverse agonist combined to psychological approach to bettercope with the stressors related to anorexia and drug dependence.