[Dynamic changes of sciatic nerve conduction velocity in rats infected with Toxoplasma gondii].

OBJECTIVE: To observe the dynamic changes of sciatic nerve conduction velocity of Toxoplasma gondii-infected rats at different time points.

METHODS: Twenty SD rats were randomly divided into control group and Toxoplasma gondii infection group. Rats in T. gondii infection group were intraperitoneal injected with 4x10(7) T. gondii tachyzoites, while those in control group were given equivalent normal saline. Motor and sensory nerve conduction velocities (MNCV, SNCV) in sciatic nerve were measured by Medtronic Keypoint4 Workstation electromyography at pre-infection, and 2, 4, 8, 12 months post-infection.

RESULTS: Within two months after infection, there was no difference in SNCV and MNCV between control group and infection group (P>0.05). From 4 months after T. gondii injection, infected rats began to show the slowness of SNCV and MNCV, which progressed with the course of infection. At 4, 8, and 12 months after infection, SNCV and MNCV of infection group were (35.26±3.02) and (25.94±3.20) m/s, (33.57±2.27) and (22.75±2.31) m/s, and (32.38±2.38) and (22.03±2.08) m/s, respectively. Compared with control group, SNCV and MNCV of infection group reduced by (7.47±2.11)% and (12.57±1.89)%, (8.92±2.64)% and (13.72±2.65)%, and (12.18±1.94)% and (15.46±2.37)%, respectively (P<0.05).

CONCLUSION: From 4 months after infection, Toxoplasma gondii-infected rats show a slowness of motor and sensory nerve conduction velocities in sciatic nerve.