Marinescu Alina-Măriuca, Labouesse Marie A
Brain, Wire and Behavior Group, Translational Nutritional Biology Laboratory, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland.
Neuroscience Center Zurich, University of Zurich, ETH Zurich, Zurich, Switzerland.
Front Neurosci. 2024 Jul 30;18:1437210. doi: 10.3389/fnins.2024.1437210. eCollection 2024.
Feeding behavior is a complex physiological process regulated by the interplay between homeostatic and hedonic feeding circuits. Among the neural structures involved, the nucleus accumbens (NAc) has emerged as a pivotal region at the interface of these two circuits. The NAc comprises distinct subregions and in this review, we focus mainly on the NAc shell (NAcSh). Homeostatic feeding circuits, primarily found in the hypothalamus, ensure the organism's balance in energy and nutrient requirements. These circuits monitor peripheral signals, such as insulin, leptin, and ghrelin, and modulate satiety and hunger states. The NAcSh receives input from these homeostatic circuits, integrating information regarding the organism's metabolic needs. Conversely, so-called hedonic feeding circuits involve all other non-hunger and -satiety processes, i.e., the sensory information, associative learning, reward, motivation and pleasure associated with food consumption. The NAcSh is interconnected with hedonics-related structures like the ventral tegmental area and prefrontal cortex and plays a key role in encoding hedonic information related to palatable food seeking or consumption. In sum, the NAcSh acts as a crucial hub in feeding behavior, integrating signals from both homeostatic and hedonic circuits, to facilitate behavioral output via its downstream projections. Moreover, the NAcSh's involvement extends beyond simple integration, as it directly impacts actions related to food consumption. In this review, we first focus on delineating the inputs targeting the NAcSh; we then present NAcSh output projections to downstream structures. Finally we discuss how the NAcSh regulates feeding behavior and can be seen as a neural hub integrating homeostatic and hedonic feeding signals, via a functionally diverse set of projection neuron subpopulations.
进食行为是一个复杂的生理过程，受体内平衡和享乐性进食回路之间相互作用的调节。在所涉及的神经结构中，伏隔核（NAc）已成为这两个回路界面的关键区域。NAc由不同的亚区域组成，在本综述中，我们主要关注NAc壳（NAcSh）。体内平衡进食回路主要位于下丘脑，确保生物体在能量和营养需求方面的平衡。这些回路监测外周信号，如胰岛素、瘦素和胃饥饿素，并调节饱腹感和饥饿状态。NAcSh接收来自这些体内平衡回路的输入，整合有关生物体代谢需求的信息。相反，所谓的享乐性进食回路涉及所有其他非饥饿和饱腹感过程，即与食物消费相关的感官信息、联想学习、奖励、动机和愉悦感。NAcSh与腹侧被盖区和前额叶皮质等与享乐主义相关的结构相互连接，并在编码与美味食物寻求或消费相关的享乐信息方面发挥关键作用。总之，NAcSh在进食行为中起着关键枢纽的作用，整合来自体内平衡和享乐性回路的信号，通过其下游投射促进行为输出。此外，NAcSh的参与不仅限于简单的整合，因为它直接影响与食物消费相关的行为。在本综述中，我们首先专注于描绘靶向NAcSh的输入；然后我们展示NAcSh向下游结构的输出投射。最后，我们讨论NAcSh如何调节进食行为，并可被视为一个通过功能多样的投射神经元亚群整合体内平衡和享乐性进食信号的神经枢纽。
