To observe the effects of acupuncture treatment and nNOS-PSD-95 complex on abnormal infrared thermal imaging features in depression model rats using infrared thermography.

Fifty SPF grade SD rats were selected and randomly divided into 6 groups, including normal group, model group (intraperitoneal injection of 0.2 mg·kg^-1·d^-1of reserpine), acupuncture group, ZL006 group. There were 9 rats in the normal group and model group, and 8 rats in each of the remaining groups. The changes in body weight and anal temperature were observed. Open field test, sucrose preference test and forced swimming test were applied to observe depression like behaviors. The mechanical pain threshold measurement and head scratching frequency detection were used to observe thee pain behaviors. After intervention, infrared thermal imaging device was used to observe the characteristics of infrared thermal imaging of the rats. Enzyme linked ELISA was used to detect the expression levels of 5-hydroxytryptamine (5-HT) in each group, nitrate reductase method was used to detect the expression levels of nitric oxide (NO), and Western blot was used to detect the expression levels of brain-derived neurotrophic factor (BDNF) content.

There were no significant differences in body weight, anal temperature or behavior among the groups before intervention (P>0.05). After intervention, compared with those of the normal group, the weight of the remaining groups decreased (P<0.001), and the anal temperature of the model group and ZL006 group decreased (P<0.01, P<0.001). Compared with those in the model group, the anal temperature in the acupuncture group significantly increased (P<0.01). Compared with the model group, the acupuncture group and Zl006 group improved depressive like behavior (P<0.05, P<0.001) and pain behavior (P<0.05, P<0.01, P<0.001), down-regulated the expression levels of NO in the hippocampal CA3 region (P<0.01), up-regulated BDNF expression levels（P<0.001）and up-regulated the expression level of 5-HT in the hippocampal CA3 region in the acupuncture group（P<0.01）. Infrared thermal imaging showed that after intervention，compared with those of the normal group，the mean head temperature，the mean trunk temperature and the minimum tail temperature of the model group decreased（P<0.05，P<0.01），the mean temperature difference（△T）between “Fengchi（GB20？）” and “Yangbai（GB14）” increased（P<0.01，P<0.001），and the △T of “Shenshu（BL23）” decreased（P<0.05）. Compared with those of the model group，the mean trunk temperature and the minimum tail temperature at the tail root of the acupuncture group and ZL006 group increased（P<0.05，P<0.01），the △T of Shaoyang，“Fengchi（GB20）” and “Yangbai（GB14）” decreased（P<0.01，P<0.001），and the △T of “Shenshu（BL23）” increased in the acupuncture group（P<0.01）.

Infrared thermal imaging of depression model rats shows the “cold phenomenon” of relatively low temperature at the overall and “Shenshu（BL23）” on the body surface，while the partial Shaoyang meridian points on the head are relatively high temperature. Acupuncture may regulate the “cold phenomenon” and participate in the antidepressant effects by regulating the Shaoyang pivot，and nNOS-PSD-95 complex may affect Shaoyang pivot function.