Carolina Peixoto Magalhães

Modulatory role of serotonin on feeding behavior

Abstract The appearance, the odor, and the flavor of foods, all send messages to the encephalic area of the brain. The hypothalamus, in particular, plays a key role in the mechanisms that control the feeding behavior. These signals modulate the expression and the action of anorexigenic or orexigenic substances that influence feeding behavior. The serotonergic system of neurotransmission consists of neurons that produce and liberate serotonin as well as the serotonin-specific receptor. It has been proven that some serotonergic drugs are effective in modulating the mechanisms of control of feeding behavior. Obesity and its associated illnesses have become significant public health problems. Some drugs that manipulate the serotonergic systems have been demonstrated to be effective interventions in the treatment of obesity. The complex interplay between serotonin and its receptors, and the resultant effects on feeding behavior have become of great interest in the scientific community.

Effects of early weaning on the circadian rhythm and behavioral satiety sequence in rats

The objective of this work was to study the effect of early weaning on circadian rhythm and the behavioral satiety sequence in adult rats. Male Wistar rat pups were weaned for separation from the mother at 15 (D15), 21 (D21) and 30 (D30) days old. Body weight and food intake was measured every 30 days until pups were 150 days old. At 90 days of age, the circadian rhythm of food intake was evaluated every 4h for three days. Behavioral satiety was evaluated at 35 and 100 days of age. This work demonstrated that body weight and food intake were not altered, but the behavioral satiety sequence demonstrated that the D15 group delayed satiety compared with the D30 group at 100 days of age. In the circadian rhythm of the food intake study, early weaning (D15) changed food intake in the intermediary period of the light phase and in the intermediary period of the dark phase. In conclusion, our study showed that early weaning may alter the feeding behavior mainly in relation to satiety and the circadian rhythm of feeding. It is possible that the presence of other environmental stimuli during early weaning can cause hyperphagia and deregulate the mechanisms of homeostasis and body weight control. This study supports theories that depict insults during early life as determinants of chronic diseases.

Efeitos do tratamento neonatal com inibidor seletivo de recaptura da 5-HT sobre o desenvolvimento anatômico crânio-encefálico

Neonatal repercussion researched of the serotonin selective recapture inibitor (SSRI) chronic treatment about the somatic growth, of the encephalon and skull. Male rats were divided into groups: control (NaCl) and Cit (10 microL/Kg citalopram 10 mg). In 21 post birth days were measured body weight, side axle , front and rear and skull circle. At 8, 15, 22 days after birth, animals were sacrified for the encephalon withdrawal to evaluate the measurements mentioned above. SSRI use caused body growth deficit, skull and encephalon reduction. The retard is possibly caused by the magnitude change of the trophic serotonin action over the skull-facial morphogenesis, reinforcing the serotoninergic system participation over the somatic and ontogenic growth. The SSRI possible hypophagic effects are not discarded.