Figure 1.
Patients suffering from BPD are less heat pain sensitive independent of the val158met polymorphism.
(A) Genotype distribution of the val158met polymorphism in healthy controls (open) and BPD patients (filled bars) do not differ. (B) Heat pain perception was markedly reduced in BPD. Dose-response function in the pretest session (circles) and stimulus temperatures applied during fMRI (squares) did significantly differ between controls and BPD (ns p>0.4; * p<0.05; ** p<0.01; *** p<0.001, students t-test).
Figure 2.
Association between COMT genotype and pain sensitivity.
A: Lower heat pain perception in BPD in response to 43°C does not depend upon the val158met polymorphism. ns p>0.3, BPD and control, respectively; * p<0.05; ** p<0.01, students t-test. B: Stimulus temperatures for the induction of a heat pain sensation of NRS 40 decreases with the number of met alleles in healthy volunteers but not in BPD patients (ns p>0.19; (*) p<0.1; * p<0.05, students t-test).
Figure 3.
Association between COMT genotype and fMRI activation during painful stimulation in frontal brain areas.
Significant correlations were observed for both stimulus conditions within the dorsolateral prefrontal cortex (DLPFC; A,B). Furthermore, the posterior parietal cortex (PPC; C) and the lateral globus pallidus (LGP; D) also displayed significant correlation during both conditions. Statistics and regression lines for group means are shown in gray (all 50 subjects), black (BPD), and dashed (Control), respectively; significant Pearson product moment correlation * p<0.05, ** p<0.01, *** p<0.001, versus r = 0.
Figure 4.
Association between COMT genotype and fMRI activation during painful stimulation in the anterior and posterior insula.
Significant correlations were observed during condition 1 within the anterior (A,B) and posterior insula (C), claustrum (D) and postcentral gyrus (D). Labeling as in Fig. 2, * p<0.05, ** p<0.01.
Figure 5.
Association between COMT genotype and fMRI activation during painful stimulation in additional brain areas.
(A) Left precentral gyrus, (B) Superior frontal gyrus, (C) Middle occipital gyrus, (D) Right precentral gyrus, (E) Posterior cingulated cortex, (F) Dorsolateral prefrontal cortex. Statistics and regression lines for group means are shown in gray (all 50 subjects), black (BPD), and dashed (Control), respectively; significant Pearson product moment correlation * p<0.05, ** p<0.01, *** p<0.001, versus r = 0.
Table 1.
Group-specific regression analyses.
Figure 6.
Brain areas activated in response to subjectively adjusted heat pain correlate with COMT val158met polymorphism.
During subjectively similar intense heat pain perception (individual temperature in BPD 43°C in healthy controls), posterior parietal cortex (A), lateral globus pallidus (LGP; B) and the posterior cingulate cortex (PPC; C) displayed significant correlation with COMT-polymorphism. Labelling as in Fig. 2,* p<0.05.