Figure 2.

Vagal afferent mechanosensitivity in WT and TNX‐KO mice

Responses to distension from single vagal afferent units innervating the stomach in WT vs. KO. Nerve discharge rate (histogram) was increased in KO in both spontaneous and distended (1 mL of fluid in stomach) conditions (A). B, corresponding raw trace to the nerve discharge rate. Spontaneous (C) (P = 0.0003) and distension (P < 0.0001) induced afferent firing (D) was significantly increased in TNX‐KO compared to WT, (n = 14 WT afferent units vs. n = 18 KO afferent units). Addition of baclofen (100 μm) significantly reduced both spontaneous (P < 0.0001) and distension (P < 0.0001) induced firing back to levels similar to those observed in WT mice (C and D) (n = 23 KO afferent units). Baclofen also reduced WT spontaneous (P < 0.0001) and distension (P = 0.028) induced firing (C and D) (n = 22 WT afferent units). There was no change in gastric compliance to 1 mL of Krebs over 1 min in WT vs. TNX‐KO mice (n = 12 WT vs. n = 12 KO). E, statistical analysis was performed using an unpaired t test.