Nucleus tractus solitarius mediates hyperalgesia induced by chronic pancreatitis in rats

Figure 7 Inactivating excitatory neurons within the caudal nucleus tractus solitarius alleviates visceral hypersensitivity in rats with chronic pancreatitis. A: The schematic diagram of behavioral experiment (left) and rAAV2/9-CaMKIIa-hM4Di/hM3Dq-mCherry construct (right); B: A representative image showing that the expression of hM4Di-mCherry was confined within the commissure and medial nuclei of the caudal nucleus tractus solitarius (NTS). Bar = 0.4 mm. C: Inhibiting caudal NTS excitatory neurons via i.p. clozapine-N-oxide injection significantly increases the abdominal withdraw threshold (AWT) in chronic pancreatitis rats, while activating these neurons does not influence the AWT. n = 6 rats in mCherry, Gq, and Gi groups, one-way ANOVA. ^bP < 0.01, Gi vs mCherry. AWT: Abdominal withdraw threshold; CC: Central canal; CNO: Clozapine-N-oxide; SolM: Nucleus of the solitary tract, medial part; SolC: Nucleus of the solitary tract, commissural part; Gr: Gracile nucleus; TNBS: Trinitrobenzene sulfonic acid.