Estrogen augmented visceral pain and colonic neuron modulation in a double-hit model of prenatal and adult stress

Figure 1 Primary afferent responses to colorectal distention. A: Chronic prenatal stress (CPS) plus chronic adult stress (CAS) model. Pregnant dams were subjected to prenatal stress from on day 11 of gestation. Ovariectomy (OVX) or sham surgery was performed on female prenatal-stress offspring on day 56. Daily Letrozole was initiated on day 49, 2 wk prior to initiation of adult stress. Treatment was continued through the stress protocol; B: Spontaneous activity (SA) of single afferent units in male and female control rats (n = 70 fibers in 6 rats in each group, t-test, ^aP < 0.05); C: Average response to graded colorectal distention (CRD) of 56 afferent fibers in 6 male and 70 afferent fibers in 6 female control rats; two-way analysis of variance (ANOVA; ^aP < 0.05 vs the same pressure male group); D: Responses of low-threshold (LT) fibers to CRD in 42 fibers in 6 male rats and 40 fibers in 6 female control rats (ANOVA, ^aP < 0.05 vs the same pressure male group); E: Responses of high-threshold (HT) afferent fibers to CRD in 14 fibers in 6 male and 29 fibers in 6 female control rats; F: Effects of CAS on afferent fiber responses to CRD from 59 fibers in 6 control and 99 fibers in 6 CPS female rats; (two-way ANOVA, ^aP < 0.05 vs the same pressure control group, ^bP < 0.05 vs the same pressure CPS group); G: Effects of CAS on afferent fiber responses to CRD in control and CPS male rats (n = 6 rats, 57 fibers for control and 95 fibers for CPS female group; two-way ANOVA, ^aP < 0.05 vs the same pressure-control group).