Combined effect of early life stress and acute stress on colonic sensory and motor responses through serotonin pathways: Differences between proximal and distal colon in rats

Figures & data

Figure 1.  Effects of WAS and PCPA on colonic nociceptive threshold in normal handled (NH) and NMS rats (n = 5 in all groups except n = 4 in NMS+low-dose PCPA+WAS group). Data are presented as mean ± S.E.M. *P < 0.001 vs. NH group, ^§P < 0.001 vs. NH group, ^#P < 0.001 vs. NH+WAS group (t-tests); ^▴P < 0.001 vs. NMS+WAS group, ^†P < 0.001 vs. NMS+low-dose PCPA+WAS group (Bonferroni's correction).

Figure 2.  Effects of WAS and PCPA on colon motility in normal handled (NH) and NMS rats (n = 5 in all groups except n = 4 in NMS+low-dose PCPA+WAS group). Colon motility was assessed by the mean faecal pellet output per hour before, during and 24 h after WAS. Data are presented as mean ± S.E.M. ^§P < 0.001 vs. NH group, ^†P < 0.001 vs. NMS group, *P < 0.001 vs. NH+WAS group (t-tests); ^#P < 0.001 vs. NMS+WAS group, ^▴P < 0.001 vs. NMS+low-dose PCPA+WAS group (Bonferroni's correction).

Figure 3.  Effects of WAS and PCPA on tissue content of 5-HT in the proximal and distal colon of normal handled (NH, n = 6) and NMS (n = 8) rats. Data presented as mean ± S.E.M. 5-HT concentration in the proximal colon were significantly higher than those in the distal colon in each group (^‡P < 0.01, t-test). In the proximal colon, ^*P < 0.01 vs. NH group (n = 6), ^#P < 0.01 vs. NH+WAS group (n = 5, t-tests); ^▴P < 0.01 vs. NMS+WAS group (n = 5), ^†P < 0.01 vs. NMS+low-dose PCPA+WAS group (n = 4, Bonferroni's correction). In the distal colon, ^▴P < 0.01 vs. NMS+WAS group (n = 5), ^†P < 0.01 vs. NMS+low-dose PCPA+WAS group (n = 4, Bonferroni's correction).

Figure 4.  Effects of WAS and PCPA on faecal content of 5-HT in the proximal and distal colon of normal handled (NH, n = 6) and NMS (n = 8) rats. Data are presented as mean ± S.E.M. In the proximal and distal colon, *P < 0.01 vs. NH+WAS group (n = 5, t-tests); ^#P < 0.01 vs. NMS+WAS group (n = 5, ^▴P < 0.01 vs. NMS+low-dose PCPA+WAS group (n = 4, Bonferroni's correction).

Figure 5.  Representative EC cell staining and statistical analysis of WAS and PCPA on EC cell density in transverse sections of the proximal colon of normal handled (A, NH, n = 6), NMS (B, NMS, n = 8), NH+WAS (C, n = 5), NMS+WAS (D, n = 5), NMS+low-dose PCPA+WAS (E, n = 4), NMS+high-dose PCPA+WAS (F, n = 5) groups. Data are presented as mean ± S.E.M. *P < 0.01 vs. NH group, ^#P < 0.01 vs. NH+WAS group (t-tests); ^▴P < 0.01 vs. NMS+WAS group, ^†P < 0.01 vs. NMS+low-dose PCPA+WAS group (Bonferroni's correction). Arrow heads indicate EC cells. The scale bar is 100 μm.