Effects and mechanisms of scalp acupuncture on learning and memory in mice with lead poisoning

To study the effects and mechanism of scalp acupuncture on learning and memory ability in mice with lead poisoning.

From March 2018 to December 2018, 30 Kunming mice were randomly divided equally into the control group and the intervention group after intraperitoneal injection of lead acetate The intervention group received scalp acupuncture on the first day of the model establishment; the model group only received conventional feeding without treatment. At the same time, a control group of 15 rats was given the intraperitoneal injections of normal saline for 8 consecutive days, and only after routine feeding, no treatment was given. Determination of lead in blood was detected by Graphite Furnace Atomic Absorption Spectrometry, the Morris water maze test was used to detect the learning and memory function of mice, hydroxylamine colorimetric method was used to measure acetylcholinesterase (AChE) activity, and TUNEL staining was used to detect the apoptotic cells in the hippocampus.

The results showed that the blood lead level of the model group (231.42±12.53µg/L) was significantly higher than that of the control group (20.43±4.62µg/L) (P<0.05); and there was no significant difference in blood lead content between the intervention group (228.12±5.21µg/L) and the model group. The Morris water maze test showed that from the fourth day of the orientation navigation experiment, the escape latency of the model group (22.2±4.10s) was longer than that of the control group (13.64±2.93s) (P<0.05); besides, from the third day, the escape latency of mice in the intervention group (13.52±9.18s) was significantly shortened compared with the model group (19.95±3.52s). In the space exploration experiment, in terms of passing through the platform, the distance (1.57±0.49m) and time (15.54±3.72s) of mice in the model group were longer than that of mice in the control group (0.73±0.44m, 3.24±2.24s) (P<0.05), the distance (0.41±0.28m) and time (3.0±1.93s) of mice in the intervention group were shorter than that of mice in the model group, and the difference was statistically significant (P<0.05). The apoptosis rate of hippocampus in the model group (8.79±0.37%) was significantly higher than that in the control group (3.56±0.44%) (P<0.05), and the apoptosis rate of hippocampus in the intervention group (4.36±0.12%0 was significantly lower than that in the model group (P<0.05). The expression of AchE in the model group (0.5±0.13U/ug) was significantly higher than that in the control group (0.23±0.04U/ug), but there was no significant difference in the AChE activity between the intervention group and the model group.

In conclusion, scalp acupuncture can improve the learning and memory ability of mice with lead poisoning, and the decrease of hippocampal apoptotic cells may be a possible mechanism for the improvement of learning and memory function.