Feeding behaviour after injection of α-adrenergic receptor agonists into the median raphe nucleus of food-deprived rats
| Autor: | Marta Aparecida Paschoalini, Mariana Graciela Terenzi, Rafael Appel Flores, Aparecida Marcelino de Nazareth, Anderson Savaris Ribas, José Marino-Neto, Moacir Serralvo Faria |
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| Rok vydání: | 2012 |
| Předmět: |
Agonist
Male medicine.medical_specialty Median raphe nucleus Adrenergic receptor medicine.drug_class Drinking Behavior Experimental and Cognitive Psychology Inhibitory postsynaptic potential Clonidine Eating Phenylephrine Behavioral Neuroscience Sniffing Food intake Internal medicine medicine Reaction Time Animals Adrenergic receptors Rats Wistar Receptor Dose-Response Relationship Drug Chemistry Feeding Behavior Rats Endocrinology Raphe Nuclei Food Deprivation Adrenergic alpha-Agonists medicine.drug |
| Zdroj: | Physiology & Behavior. 105(2):220-229 |
| ISSN: | 0031-9384 |
| DOI: | 10.1016/j.physbeh.2011.08.028 |
| Popis: | This study investigated the participation of median raphe nucleus (MnR) α1-adrenergic receptors in the control of feeding behaviour. The α1-adrenergic agonist phenylephrine (PHE) and α2-adrenergic agonist clonidine (CLON) (at equimolar doses of 0, 6 and 20 nmol) were injected into the MnR of: a) rats submitted to overnight fasting (18 h); or b) rats maintained with 15 g of lab chow/day for 7 days. Immediately after the drug injections, the animals were placed in the feeding chamber and feeding and non-ingestive behaviours such as grooming, rearing, resting, sniffing and locomotion were recorded for 30 min. The results showed that both doses of PHE injected into the MnR of overnight fasted animals decreased food intake accompanied by an increase in the latency to start feeding. A reduction in feeding duration was observed only after treatment of the MnR with the 20 nmol dose of PHE. Both locomotion duration and sniffing frequency increased after injection with the highest dose PHE into the MnR. Feeding frequency and the other non-ingestive behaviours remained unchanged after PHE treatment in the MnR. Both doses of PHE injected into the MnR of food-restricted rats decreased food intake. This hypophagic response was accompanied by a decrease in feeding duration only after treatment of the MnR with the highest dose of PHE. The latency to start feeding and feeding frequency were not affected by injection of either dose of PHE into the MnR. While both doses of PHE increased sniffing duration, the highest dose of PHE increased resting duration and resting frequency. Treatment with CLON into the MnR did not affect feeding behaviour in either of the food deprivation conditions. The present results indicate the inhibitory functional role of α1-adrenergic receptors within the MnR on feeding behaviour. |
| Databáze: | OpenAIRE |
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