Effects of Electroacupuncture of Different Frequencies on the Release Profile of Endogenous Opioid Peptides in the Central Nerve System of Goats

Table 1

M-EMK immunoactivities induced by different frequencies in the CNS (mean ± SD, 𝑛=7).

Nuclei; and areas	Sham control	0 Hz	2 Hz	40 Hz	60 Hz	100 Hz	Correlation coefficients
ACB	15.60 ± 1.69^c	15.30 ± 2.97^c	24.56 ± 2.50^b	32.69 ± 3.92^a	35.15 ± 4.41^a	22.59 ± 2.89^b	0.888**
SA	15.14±1.53^e	14.77 ± 2.39^e	25.05 ± 1.94^d	54.95 ± 3.50^b	60.51 ± 4.35^a	33.81 ± 3.72^c	0.923**
CAU	15.00±1.92^c	14.35 ± 3.18^c	22.78 ± 2.92^b	25.24 ± 5.64^b	32.66 ± 3.47^a	26.88 ± 5.48^b	0.724**
AMY	10.47±1.58^d	10.04 ± 2.43^d	20.49 ± 3.28^c	35.06 ± 7.69^b	47.28 ± 5.56^a	38.45 ± 7.97a^b	0.795**
SON	33.21±2.58	32.99 ± 5.03	30.54 ± 6.16	31.68 ± 8.17	31.90 ± 6.49	33.73 ± 5.61	0.071
PVH	18.22±3.59^b	17.95 ± 4.25^c	35.01 ± 6.18^b	47.38 ± 7.63^a	46.70 ± 10.22^a	40.76 ± 3.55^ab	0.734**
VMH	11.95±1.72^b	11.09 ± 3.29^b	18.47 ± 2.56^b	36.56 ± 8.99^a	40.65 ± 10.10^a	38.19 ± 9.27^a	0.735**
PAG	8.05±0.77^c	7.75 ± 1.16^c	20.53 ± 3.60^b	23.29 ± 4.26^b	33.71 ± 6.73^a	16.74 ± 2.51^b	0.808**
DR	11.56±1.51^c	11.34±4.03^c	16.73±2.26^b	29.01±2.28^a	26.30±2.70^a	20.49±3.25^b	0.837**
SN	12.72±2.05^b	12.42±2.74^b	15.14±3.02^b	22.95±1.58^a	22.64±5.20^a	20.36±1.51^a	0.721**
PBN	7.69±1.04^c	7.18±1.61^c	9.71±1.52^c	18.90±2.93^b	26.44±3.53^a	29.13±3.01^a	0.656**
LC	11.69±1.15^c	10.93±0.89^c	15.68±2.97^b	27.49±2.11^a	27.80±3.60^a	25.15±3.31^a	0.799**
NRM	14.15±1.39	13.77±2.74	15.77±1.55	15.53±3.92	17.07±2.27	15.76±4.28	0.263
SCD	5.22±0.55^b	5.22±0.77^b	7.31±0.67^a	6.00±0.32^b	5.85±0.58^b	5.44±0.38^b	0.123

ACB: nucleus accumbens, SA: septal area, CAU: caudate nucleus, AMY: amygdala, SON: supraoptic nucleus, SN: substantia nigra, PAG: periaqueductal gray, NRM: nucleus raphe magnus, PBN: parabrachial nucleus, LC: locus ceruleus, DR: dorsal raphe nucleus, SCD: spinal cord dorsal horn, PVH: paraventricular nucleus of hypothalamus, VMH: ventromedial nucleus of hypothalamus.
Note: There was difference (𝑃<0.05) between the values with different letters, and no difference (𝑃>0.05) with the same letters in a line. *means the levels of the endogenous opioid peptides correlate with the pain thresholds at the 0.05 level, and the levels at the 0.01 level. **The letters and symbols in the following tables have the same meanings as the table above.