1. To study the influence of antidotes on low-level
sarin-induced impairment of cognitive functions, the rats were exposed to three various low concentrations of
sarin (LEVEL 1-3) for 60 minutes in the inhalation chamber. In addition, one group of rats was exposed to LEVEL 2 of
sarin repeatedly. 2. Testing of cognitive functions was carried out using the Y-maze evaluating learning and spatial memory. The correct averse behavior of
sarin-exposed rats in the Y-maze was tested several times within four weeks following
sarin inhalation exposure and antidotal treatment to look for any
cognitive impairments. 3. The results were compared to the Y-maze performance of
sarin-exposed rats without antidotal treatment and control rats exposed to pure air instead of
sarin with or without antidotal treatment. While antidotal treatment was able to eliminate a short-term deficiency in the Y-maze performance in rats exposed to the LEVEL 1 of
sarin, a significant decrease in the Y-maze performance in rats exposed to
sarin at the LEVEL 2 and 3 was only shortened.
Sarin-induced spatial memory impairments in rats exposed repeatedly to
sarin at the LEVEL 2 was also shortened when rats were treated following each
sarin inhalation exposure. 4. The findings confirm that antidotes currently used for
nerve agent poisonings are beneficial for the treatment of rats singly or repeatedly exposed to non-convulsive symptomatic or even clinically asymptomatic concentrations of
sarin.