Nerve Conduction Velocity In Mice Research Articles

ALTERATIONS OF MOTOR NERVE FUNCTIONS IN ANIMALS EXPOSED TO MOTORCYCLE EXHAUST

The effect of motorcycle exhaust (ME) on the motor nerve was studied using animals exposed to the exhaust by inhalation, intratracheal, or intraperitoneal administration of ME particulate (MEP). A 4-wk ME inhalation and intratracheal instillation of MEP for 1 d in rats or intraperitoneal administration of MEP (0.5 g/kg/d for 1 d and 0.1 g/kg/d for 2 d) in mice significantly decreased both rota-rod performance and motor nerve conduction velocity. The effect of some polycyclic aromatic hydrocarbons on the motor nerve was also investigated. Treatment with benzo[a]pyrene (0.05 and 0.1 g/kg/d for 3 d), but not pyrene (0.1 g/kg/d for 3 d), resulted in significant decrease of motor nerve conduction velocity in mice. Moreover, the Na + ,K + -ATPase activities of sciatic nerves isolated from ME-, MEP-, or benzo[a]pyrene-exposed animals were decreased. Treatment with pyrene did not markedly affect the Na + ,K + -ATPase activity of sciatic nerve. The rats exposed to ME for 4 wk showed increases in blood and sciatic nerve manganese levels. Results indicate that motorcycle exhaust produces adverse effects on the motor nerve, which is associated with a fall in nerve Na + ,K + -ATPase activity.

Nerve conduction velocity in mice: a new method with results and analysis of variation.

A new method for measuring nerve conduction velocity (CV) in the tails of awake mice in a temperature-controlled environment is described and applied. Sixty male HS mice, with an average age of 65.6 days, had a mean (±SE) CV of 21.01±0.29 ms−1. Thirty-five male mice in four inbred strains (DBA/1J, C3H/HeJ, C57BL/6J, A/J), aged 60 to 66 days, had higher mean CVs. These inbred strains differ among themselves in mean CV. Repeated testing shows that CV is a stable trait over time, especially in genetically heterogeneous mice. Broad-sense heritability for CV probably exceeds 0.4, greater than previously reported.

Effect in vivo of a sub-hypnotic dose of ethanol on nerve conduction velocity in mice

Relative nerve conduction time (reciprocal of velocity), before and after administration of ethanol, was studied in the caudal nerves of 58 mice. Doses of 1.4, 2.0, 2.5, 3.0, and 4.24 g ethanol/kg body wt., given i.p., were used. The tail was maintained at 37.0° and a control (saline) injection preceeded the ethanol injection. Doses of 1.4 and 2.0 g/kg did not produce significant effects on conduction time but doses of 2.5, 3.0, and 4.24 g/kg did, the relative conduction times twelve minutes after ethanol increasing by 1.2, 1.8, and 3.1 percent, respectively. This appears to be the first controlled demonstration of an acute in vivo effect of ethanol on conduction velocity.

Nervous system function: Behavioral influences of gene effects on peripheral nerve conduction velocity in mice

Strains of mice different with regard to caudal nerve conduction velocity are shown to differ in reflex behavior which involves sciatic nerve function. The pattern of behavioral differences is exactly that which would be predicted if gene differences effecting caudal nerve had simultaneous effects on sciatic velocity. About 12% of the phenotypic variance in this behavior is due to additive genetic variance.