Scopinho A A, Resstel L B M, Corrêa F M A
Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.
Br J Pharmacol. 2008 Nov;155(5):752-6. doi: 10.1038/bjp.2008.295. Epub 2008 Jul 21.
Control of food intake is a complex behaviour which involves many interconnected brain structures. The present work assessed if the noradrenergic system in the lateral septum (LS) was involved in the feeding behaviour of rats.
In the first protocol, the food intake of rats was measured. Then non-food-deprived animals received either 100 nL of 21 nmol of noradrenaline or vehicle unilaterally in the LS 10 min after local 10 nmol of WB4101, an alpha(1)-adrenoceptor antagonist, or vehicle. In the second protocol, different doses of WB4101 (1, 10 or 20 nmol in 100 nL) were microinjected bilaterally into the LS of rats, deprived of food for 18 h and food intake was compared to that of satiated animals.
One-sided microinjection of noradrenaline into the LS of normal-fed rats evoked food intake, compared with vehicle-injected control animals, which was significantly reduced by alpha(1)-adrenoceptor antagonism. In a further investigation, food intake was significantly higher in food-deprived animals, compared to satiated controls. Pretreatment of the LS with WB4101 reduced food intake in only food-deprived animals in a dose-related manner, suggesting that the LS noradrenergic system was involved in the control of food intake.
Activation by local microinjection of noradrenaline of alpha(1)-adrenoceptors in the LS evoked food intake behaviour in rats. In addition, blockade of the LS alpha(1)-adrenoceptors inhibited food intake in food-deprived animals, suggesting that the LS noradrenergic system modulated food intake behaviour and satiation.
食物摄入的控制是一种复杂行为，涉及许多相互连接的脑结构。本研究评估外侧隔区（LS）的去甲肾上腺素能系统是否参与大鼠的进食行为。
在第一个实验方案中，测量大鼠的食物摄入量。然后，在局部注射10 nmol α(1)-肾上腺素能受体拮抗剂WB4101或溶剂10分钟后，未处于食物剥夺状态的动物单侧接受100 nL含21 nmol去甲肾上腺素或溶剂的注射。在第二个实验方案中，将不同剂量（100 nL中含1、10或20 nmol）的WB4101双侧微量注射到禁食18小时的大鼠LS中，并将其食物摄入量与饱足动物的进行比较。
与注射溶剂的对照动物相比，向正常进食大鼠的LS单侧微量注射去甲肾上腺素可诱发食物摄入，而α(1)-肾上腺素能受体拮抗作用可显著减少这种摄入。在进一步研究中，与饱足对照相比，食物剥夺动物的食物摄入量显著更高。用WB4101预处理LS仅以剂量相关的方式减少了食物剥夺动物的食物摄入量，这表明LS去甲肾上腺素能系统参与了食物摄入的控制。
局部微量注射去甲肾上腺素激活LS中的α(1)-肾上腺素能受体可诱发大鼠的食物摄入行为。此外，阻断LS中的α(1)-肾上腺素能受体可抑制食物剥夺动物的食物摄入，这表明LS去甲肾上腺素能系统调节食物摄入行为和饱腹感。
