Supplemental Figure 4 - Sex Differences in Shock-Induced Sensitivity

Published Image

Figure S4. Sex differences in footshock-induced expression of hyperalgesic priming. (A) There was no sex difference in the magnitude of footshock-induced mechanical sensitivity among nive mice. (B) CFA-primed mice males exhibited expression of hyperalgesic priming at the site of previous injury whereas female CFA-primed mice did not. (C) Naive mice did not express footshock induced changes in sensitivity, but (D) male CFA-primed mice exhibited expression of hyperalgesic priming after footshock in their right paw as well (which had not been injured by CFA). Data expressed as mean value +/- SEM, *** indicates p < 0.001.

Statistics

## CFA-primed: Left Paws

a <- Left_data %>%
  melt(id.vars = c("ID","Sex","CFA")) %>% 
  filter(CFA == "CFA")

b <- aov(data=a,value~variable*Sex)
summary(b)

##              Df Sum Sq Mean Sq F value               Pr(>F)    
## variable      4 2.6377  0.6594   36.44 < 0.0000000000000002 ***
## Sex           1 0.4122  0.4122   22.78         0.0000096220 ***
## variable:Sex  4 0.9339  0.2335   12.90         0.0000000637 ***
## Residuals    70 1.2666  0.0181                                 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

c <- a %>%
  group_by(variable) %>%
  pairwise_t_test(value~Sex)

tt(c)

variable	.y.	group1	group2	n1	n2	p	p.signif	p.adj	p.adj.signif
Post-CFA Baseline	value	Male	Female	8	8	0.2360000	ns	0.2360000	ns
3 hours	value	Male	Female	8	8	0.0000190	****	0.0000190	****
24 hours	value	Male	Female	8	8	0.0000155	****	0.0000155	****
3 days	value	Male	Female	8	8	0.9980000	ns	0.9980000	ns
7 days	value	Male	Female	8	8	0.9330000	ns	0.9330000	ns

Both Three and 24 hours after footshock, CFA-primed males exhibit more hypersensitvity than CFA-primed females.
There are no group differences at baseline, 3 days post shock, or 7 days post shock.

## CFA-primed: Right Paws

a <- Right_data %>%
  melt(id.vars = c("ID","Sex","CFA")) %>% 
  filter(CFA == "CFA")

b <- aov(data=a,value~variable*Sex)
summary(b)

##              Df Sum Sq Mean Sq F value            Pr(>F)    
## variable      4 2.0363  0.5091   27.21 0.000000000000123 ***
## Sex           1 0.6361  0.6361   34.00 0.000000155168408 ***
## variable:Sex  4 1.1357  0.2839   15.18 0.000000005554703 ***
## Residuals    70 1.3095  0.0187                              
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

c <- a %>%
  group_by(variable) %>%
  pairwise_t_test(value~Sex)

tt(c)

variable	.y.	group1	group2	n1	n2	p	p.signif	p.adj	p.adj.signif
Post-CFA Baseline	value	Male	Female	8	8	0.3350000000	ns	0.3350000000	ns
3 hours	value	Male	Female	8	8	0.0000000132	****	0.0000000132	****
24 hours	value	Male	Female	8	8	0.0000001120	****	0.0000001120	****
3 days	value	Male	Female	8	8	0.9250000000	ns	0.9250000000	ns
7 days	value	Male	Female	8	8	0.7800000000	ns	0.7800000000	ns

Both Three and 24 hours after footshock, CFA-primed males exhibit more hypersensitvity than CFA-primed females.
There are no group differences at baseline, 3 days post shock, or 7 days post shock.

Similar statistical results for the left and right hind paws indicate that the expression of hyperalgesic priming is not limited to the site of previous injury in male mice.