An objective approach to assess colonic pain in mice using colonometry

The present study presents a non-surgical approach to assess colonic mechanical sensitivity in mice using colonometry, technique which stretch-reflex contractions are measured by recording intracolonic pressures during saline infusion into the distal colon constant rate. Colonometrical has been used function healthy individuals and patients with neurological disorders. Here we found that colonometry can also be implemented mice, an optimal rate of 1.2 mL/h. Colonometrograms showed intermittent pressure rises was caused periodical contractions. In sceneries hypersensitivity generated post 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced inflammation, following chemogenetic activation primary afferent neurons, or immediately after noxious stimulation colorectal distension (CRD), amplitude (A ICP ) markedly elevated accompanied faster rising (ΔP/Δt). Colonic hypersensitivity-associated A elevation result enhanced strength contraction reflected heightened activity sensory reflex pathways. increased value ΔP/Δt indicated lower threshold sensation elicited smaller volume shorter period time. Chemogenetic inhibition pathway governed Nav1.8-expressing cells attenuated TNBS-induced up-regulations , ΔP/Δt, pain behavior response CRD. These findings support colonometrograms for analysis mice.