Cholera Toxin Induces Sustained Hyperexcitability in Submucosal Secretomotor Neurons in Guinea Pig Jejunum

Abstract

Background & Aims: Neural mechanisms underlying cholera toxin (CT)-induced intestinal hypersecretion remain unclear. We investigated long-term excitability changes in vasoactive intestinal peptide (VIP) and neuropeptide Y (NPY) secretomotor neurons after prolonged luminal exposure to CT. Methods: Isolated segments of guinea pig jejunum were incubated with saline or CT ± neurotransmitter antagonist in the lumen; the submucosal plexus was then dissected clear, circumferentially adjacent to intact mucosa. Synaptic inputs and firing properties of S neurons in ganglia next to the mucosa in control saline were studied using intracellular recording. Neurons were processed for VIP and NPY immunoreac..