Effect of High Frequency Repetitive Transcranial Magnetic Stimulation on Aged Mice with Postoperative Cognitive Dysfunction Based on BDNF/TrkB Signaling Pathway
Year: 2024
Type: article
Abstract: Objective To explore the effect and its mechanism of high frequency repetitive transcranial magnetic stimulation (rTMS) on aged mice with postoperative cognitive dysfunction (POCD). Methods A total of twenty-four 18-month-old C57BL/6J male aged mice were randomly divided into control group, operation group and rTMS group, with eight cases in each group. The rTMS group received 5 Hz rTMS real stimulation for 10 consecutive days before operation, then underwent an experimental laparotomy, and continued with another four days of rTMS real stimulation after operation, once a day, with a magnetic stimulation intensity of 0.84 T, frequency of 5 Hz, 100 pulses per sequence, a 30-second interval time, 10 repetitions for a total of 1 000 pulses. The control group and the operation group received sham stimulation for 10 days before operation, the control group did not undergo the operation, while the operation group received experimental laparotomy, and then the control group and the operation group received sham stimulation for four days. Open field test was used to evaluate motor function (percentage of time spend in the central area, total distance traveled, and average speed of movement) at the 3rd day after operation; Y-maze test was used to evaluate cognitive function (the percentage of entries into the novel arm, the percentage of time to stay in the novel arm and the total distance moved in the novel arm) at the 4th day after operation; Western blot was used to detect the protein expression levels of brain-derived neurotrophic factor (BDNF), tropomyosin related kinase B (TrkB) and nerve growth factor (NGF) in the hippocampal tissue of the mice. Results (1) Motor function: there were no significant differences in the percentage of time spent in the central area of the open field, total distance traveled and average speed of movement among the three groups (P>0.05). (2) Cognitive function: there was no significant difference in the percentage of entries into the novel arm among the three groups (P>0.05); compared with the control group, the percentage of time spent in the novel arm and the total distance moved in the novel arm in the operation group decreased significantly, and the differences were statistically significant (P<0.05). Compared with the operation group, the percentage of time spent in the novel arm and the total distance moved in the novel arm in the rTMS group increased significantly, and the differences were statistically significant (P<0.05). (3) Protein expression level of hippocampal tissue: compared with the control group, the protein expression levels of BDNF, TrkB and NGF in the hippocampal tissue in the operation group decreased significantly, and the differences were statistically significant (P<0.05). Compared with the operation group, the protein expression levels of BDNF, TrkB and NGF in the hippocampus in the rTMS group increased significantly, and the differences were statistically significant (P<0.05). Conclusion High frequency rTMS can improve POCD in aged mice, and its mechanism may be related to rTMS activating BDNF/TrkB signaling pathway and increasing NGF expression.
Source: Rehabilitation Medicine
Authors: Min LI, Xiao YANG, Lulu REN, Tingmei WU, Hong ZHANG
Language: English
Subfield: Neurology
Field: Neuroscience
Domain: Life Sciences
Open Access status: diamond
OpenAlex ID: W4411109906