NTS Neural Subtypes and Satiety Pathways: taVNS as a Novel Neuromodulatory Intervention

The global obesity epidemic has become one of the most severe public health challenges of the 21st century, and existing treatment strategies have limitations such as poor long-term adherence, significant side effects, or high invasiveness. Dysregulation of feeding behavior is the core driver of obesity, and its precise regulation depends on the complete transmission of gut-brain axis signals. The nucleus of the solitary tract (NTS), as the first central relay station for visceral afferent signals, is a key hub for the regulation of feeding homeostasis. This article reviews the peripheral signal transduction mechanisms of hunger and satiety, the core afferent pathway of the vagus nerve, and the functional heterogeneity of neuron subpopulations within the NTS, focusing on the anatomical basis, neuroimaging evidence, and preclinical and clinical research progress of transcutaneous auricular vagus nerve stimulation (taVNS) targeting the NTS to exert anti-obesity effects. Accumulating evidence suggests that taVNS may modulate the activity of satiety-promoting neurons and attenuate aberrant hyperactivity of TH⁺ catecholaminergic neurons in obesity via the auricular branch of the vagus nerve-NTS pathway, which may in turn bidirectionally suppress homeostatic and hedonic feeding, reduce energy intake, and ameliorate metabolic dysregulation. Current research still has key gaps such as unstandardized stimulation parameters, lack of large-sample long-term randomized controlled trials, and unclear interaction mechanisms between the NTS and higher brain regions. This article provides a theoretical basis for in-depth understanding of the feeding regulatory network of the NTS and the translational application of taVNS in obesity management.