Departamento de Biologia Experimental, Faculdade de Medicina, Universidade do Porto Porto, Portugal.
Front Syst Neurosci. 2012 Mar 1;6:5. doi: 10.3389/fnsys.2012.00005. eCollection 2012.
The insular cortex (IC) contains the primary sensory cortex for oral chemosensation including gustation, and its integrity is required for appropriate control of feeding behavior. However, it remains unknown whether the role of this brain area in food selection relies on the presence of peripheral taste input. Using multielectrode recordings, we found that the responses of populations of neurons in the IC of freely licking, sweet-blind Trpm5(-/-) mice are modulated by the rewarding postingestive effects of sucrose. FOS immunoreactivity analyses revealed that these responses are restricted to the dorsal insula. Furthermore, bilateral lesions in this area abolished taste-independent preferences for sucrose that can be conditioned in these Trpm5(-/-) animals while preserving their ability to detect sucrose. Overall, these findings demonstrate that, even in the absence of peripheral taste input, IC regulates food choices based on postingestive signals.
脑岛皮层(IC)包含口腔化学感觉(包括味觉)的主要感觉皮层,其完整性是适当控制进食行为所必需的。然而,尚不清楚该脑区在食物选择中的作用是否依赖于外周味觉输入的存在。使用多电极记录,我们发现自由舔食的甜味盲 Trpm5(-/-) 小鼠 IC 中神经元群体的反应受到蔗糖奖赏后效的调节。FOS 免疫反应分析表明,这些反应仅限于背侧脑岛。此外,该区域的双侧损伤消除了这些 Trpm5(-/-) 动物中可条件化的、与味觉无关的蔗糖偏好,同时保留了它们检测蔗糖的能力。总的来说,这些发现表明,即使在没有外周味觉输入的情况下,IC 也会根据摄食后的信号来调节食物选择。