Effect of electric vagal stimulation on postoperative cognitive dysfunction in aged rats / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effect of electric vagal stimulation on postoperative cognitive dysfunction in aged rats.Methods Thirty healthy Sprague-Dawley rats of both sexes,aged 18-20 months,weighing 390-550 g,were randomly divided into 3 groups (n=10 each) using a random number table:control group (group C),surgery group (group S),and electric vagal stimulation group (group V).Incision of the right carotid sheath was performed,and the vagal nerve was exposed after anesthesia in S and V groups.The right vagus nerve was stimulated for 30 min with continuous electric rectangular pulses (1 ms,10 Hz,1-2 V) after surgery in group V.The Morris water maze place navigation test was performed at 4,3,2 and 1 days before surgery and 2 days after surgery.The cognitive function was assessed using spatial probe and open field tests conducted at 2 days after surgery.The escape latency,the number of crossing the platform,the number of crossing the grid,the number of standing on the back legs,and the time animals spent in the central square were recorded.After the end of behavioral testing,venous blood samples were collected from the jugular vein for determination of concentrations of serum tumor necrosis factor-alpha (TNF-α),interleukin (IL)-1β and IL-6 using enzyme-linked immunosorbent assay.Results Compared with group C,the number of crossing the platform,the number of crossing the grid,and the number of standing on the back legs were significantly decreased,the escape latency and the time animals spent in the central square were significantly prolonged,and the concentrations of serum TNF-α,IL-1β and IL-6 were significantly increased at 2 days after surgery in group S (P＜0.05).Compared with group S,the number of crossing the platform,the number of crossing the grid,and the number of standing on the back legs were significantly increased,the escape latency and the time animals spent in the central square were significantly shortened,and the concentrations of serum TNF-α,IL-1β and IL-6 were significantly decreased at 2 days after surgery in group V (P＜0.05).Conclusion Electric vagal stimulation can improve the postoperative cognitive dysfunction in aged rats.