Electroacupuncture at Baihui (DU20) acupoint up-regulates mRNA expression of NeuroD molecules in the brains of newborn rats suffering in utero fetal distress

Abstract

NeuroD plays a key regulatory effect on differentiation of neural stem cells into mature neurons in the brain. Thus, we assumed that electroacupuncture at Baihui (DU20) acupoint in newborn rats exposed to in utero fetal distress would influence expression of NeuroD. Electroacupuncture at Baihui was performed for 20 minutes on 3-day-old (Day 3) newborn Sprague-Dawley rats exposed to in utero fetal distress; electroacupuncture parameters consisted of sparse and dense waves at a frequency of 2-10 Hz. Real-time fluorescent quantitative PCR results demonstrated that mRNA expression of NeuroD, a molecule that indicates NeuroD, increased with prolonged time in brains of newborn rats, and peaked on Day 22. The level of mRNA expression was similar between Day 16 and Day 35. These findings suggest that electro acupuncture at Baihui acupoint could effectively increase mRNA expression of molecules involved in NeuroD in the brains of newborn rats exposed to in utero fetal distress.

Keywords: Baihui (DU20) acupoint; NeuroD; brain injury; electroacupuncture; hypoxic-ischemic brain injury; in utero fetal distress; nerve regeneration; nerve repair; neural regeneration; non-acupoint; real-time fluorescent quantitative PCR.

Figure 1

Agarose gel electrophoresis results of total RNA in the brains of newborn rats exposed to in utero fetal distress. 1–3: Blank control group; 4–7: 20-minute fetal distress group; 8–11: 20-minute fetal distress + Baihui group; 12–15: 20-minute fetal distress + non-acupoint group. Gel imaging system shows distinct bands of total RNA from each sample.

Figure 2

Effects of electroacupuncture at Baihui (DU20) acupoint on NeuroD mRNA expression in the brains of newborn rats exposed to in utero fetal distress. (A) Agarose gel electrophoresis: single bands of products amplified by β-actin primers on the left and products amplified by NeuroD primers on the right are visible at 200 bp. Background is clear. (B, C) PCR amplification curves and melting curves. Left: amplification curves of β-actin; right: amplification curves of NeuroD. (D) NeuroD mRNA expression after electroacupuncture: NeuroD mRNA expression gradually increased after electroacupuncture, peaks on Day 22, and decreased on Day 35 to levels similar to Day 16. NeuroD mRNA expression was greater in the 20-minute fetal distress + Baihui group than in other groups on Days 16, 22 and 35. *P < 0.01, vs. blank control group; #P < 0.01, vs. 20-minute fetal distress group; &P < 0.05, &&P < 0.01, vs. 20-minute fetal distress + Baihui group (mean ± SD, n = 6, one-way analysis of variance and the least significant difference t-test). Day 16, 22, and 35 refers to 7, 13, and 26 days after electroacupuncture, respectively.