de Araujo Ivan E, Gutierrez Ranier, Oliveira-Maia Albino J, Pereira Antonio, Nicolelis Miguel A L, Simon Sidney A
Department of Neurobiology, Duke University Medical Center, Durham, North Carolina 27710, USA.
Neuron. 2006 Aug 17;51(4):483-94. doi: 10.1016/j.neuron.2006.07.009.
The motivation to start or terminate a meal involves the continual updating of information on current body status by central gustatory and reward systems. Previous electrophysiological and neuroimaging investigations revealed region-specific decreases in activity as the subject's state transitions from hunger to satiety. By implanting bundles of microelectrodes in the lateral hypothalamus, orbitofrontal cortex, insular cortex, and amygdala of hungry rats that voluntarily eat to satiety, we have measured the behavior of neuronal populations through the different phases of a complete feeding cycle (hunger-satiety-hunger). Our data show that while most satiety-sensitive units preferentially responded to a unique hunger phase within a cycle, neuronal populations integrated single-unit information in order to reflect the animal's motivational state across the entire cycle, with higher activity levels during the hunger phases. This distributed population code might constitute a neural mechanism underlying meal initiation under different metabolic states.
开始或终止进食的动机涉及中枢味觉和奖赏系统对当前身体状态信息的持续更新。先前的电生理和神经影像学研究表明，随着受试者状态从饥饿转变为饱腹感，特定区域的活动会减少。通过在自愿进食至饱腹的饥饿大鼠的下丘脑外侧、眶额皮质、岛叶皮质和杏仁核中植入微电极束，我们测量了神经元群体在完整进食周期（饥饿-饱腹-饥饿）不同阶段的行为。我们的数据表明，虽然大多数对饱腹感敏感的单位在一个周期内优先对独特的饥饿阶段做出反应，但神经元群体整合了单个单位的信息，以便反映动物在整个周期中的动机状态，在饥饿阶段活动水平更高。这种分布式群体编码可能构成不同代谢状态下进食起始的神经机制。
