This research identifies a specialized interoreceptor in C. elegans that allows the enteric nervous system to detect and manage salt stress. Scientists discovered that a single pharyngeal neuron, known as I3, utilizes a specific ionotropic receptor complex—comprised of GLR-9 and GLR-7—to sense ingested cations directly within the gut. While cholinergic signaling from this neuron provides immediate protection against sudden high-salt exposure, peptidergic signaling involving the neuropeptide FLP-6 is required for long-term acclimatization. The study demonstrates that these internal sensory signals travel from the enteric network to distal tissues like the intestine and epidermis, where they reprogram the expression of stress-response genes. Ultimately, this mechanism reveals how a defined neural pathway maintains physiological homeostasis by defending the organism against the toxic effects of excessive salt.

References:

• Yeon J, Kim J, Sato K, et al. An enteric neuron ionotropic receptor regulates salt stress resistance[J]. Nature, 2026: 1-10.