Yang Mingxin, Singh Arashdeep, McDougle Molly, Décarie-Spain Léa, Kanoski Scott, de Lartigue Guillaume
bioRxiv. 2023 Oct 10:2023.10.09.561580. doi: 10.1101/2023.10.09.561580.
The hippocampus (HPC), traditionally known for its role in learning and memory, has emerged as a controller of food intake. While prior studies primarily associated the HPC with food intake inhibition, recent research suggests a critical role in appetitive processes. We hypothesized that orexigenic HPC neurons differentially respond to fats and/or sugars, potent natural reinforcers that contribute to obesity development. Results uncover previously-unrecognized, spatially-distinct neuronal ensembles within the dorsal HPC (dHPC) that are responsive to separate nutrient signals originating from the gut. Using activity-dependent genetic capture of nutrient-responsive HPC neurons, we demonstrate a causal role of both populations in promoting nutrient-specific preference through different mechanisms. Sugar-responsive neurons encode an appetitive spatial memory engram for meal location, whereas fat-responsive neurons selectively enhance the preference and motivation for fat intake. Collectively, these findings uncover a neural basis for the exquisite specificity in processing macronutrient signals from a meal that shape dietary choices.
海马体（HPC）传统上因在学习和记忆中的作用而闻名，如今已成为食物摄入的控制者。虽然先前的研究主要将海马体与食物摄入抑制联系起来，但最近的研究表明它在食欲过程中起着关键作用。我们推测，促食欲的海马体神经元对脂肪和/或糖有不同反应，而脂肪和糖是导致肥胖的强大天然强化物。研究结果揭示了背侧海马体（dHPC）中以前未被认识到的、空间上不同的神经元集群，它们对来自肠道的不同营养信号有反应。通过对营养反应性海马体神经元进行活动依赖性基因捕获，我们证明了这两类神经元群体通过不同机制在促进营养物质特异性偏好方面的因果作用。糖反应性神经元编码了一顿饭位置的食欲性空间记忆印迹，而脂肪反应性神经元则选择性地增强了对脂肪摄入的偏好和动机。总的来说，这些发现揭示了处理来自一餐的大量营养素信号以形成饮食选择的精确特异性的神经基础。
