Figure 3
Effect of SNP on different subtypes of afferent nerve. (a) Responses of the multiunit mesenteric afferent fibers to ramp jejunal distension. The upper trace shows the raw recording of whole nerve discharge in the presence of SNP (4 mM), the middle trace is the number of nerve discharge in 3 s, and the lower trace shows corresponding intraluminal pressure. The multiunit discharge was divided into low threshold (LT) unit, high threshold (HT) unit, wide dynamic range (WDR) unit and mechanically insensitive afferents (MIA). The effect of SNP on the LT and HT units are shown in (b,c). (b) Time course of the excitatory effect of SNP (4 mM) on the spontaneous discharge rate of low threshold units. Top left corner shows identifiable shapes of low threshold units. n = 6 in each group, *P < 0.05 vs vehicle, Students’ t-test. (c) Time course shows the frequency of spontaneous firings of high threshold single units were not altered by adding SNP. Top left corner shows superimposed traces identifying high threshold units. n = 6 in each group, Students’ t-test.
