Parental Neuropathic Pain Influences Emotion-Related Behavior in Offspring Through Maternal Feeding Associated with DNA Methylation of Amygdale in Rats.

Chronic neuropathic pain has currently become a remarkable public health concern, considerably damaging not only the physiological but also the psychological aspects of humans. This study investigated whether neuropathic pain affects maternal care and assessed the effect of parental neuropathic pain on the development of neuropathic pain and emotion among offspring. Our results showed that mother rats suffered from chronic constriction injury (CCI) exhibited defective maternal care. The offspring fed by CCI mother rats (own or cross-fed) showed a significant increase in anxiety and anxiety-related behavior compared with that fed by sham-operated mother rats. The offspring fed by CCI mother rats also displayed decreased oxytocin expression in their supraoptic nucleus than that fed by sham-operated mother rats. Moreover, DNA methyltransferase (DNMT)1 expression in the amygdale was increased, whereas DNMT3a and DNMT3b expressions remained the same in offspring fed by CCI mother rats, as detected with immunohistochemistry and western blot analysis. In addition, the total DNA methylation in amygdale was upregulated in offspring fed by CCI mother rats. Considering the above findings, the data of this study suggest that parental neuropathic pain influences emotion-related behavior in offspring through maternal feeding behavior rather than through genetic factors and pregnancy experience that was associated with DNA methylation of amygdale in offspring.