ALMA MARIE CARDENAS
The Effects of Prenatal Methanol Exposure on Simple and Choice Reaction Time in Nonhuman Primates
Toxicology, MS
Preceptor: Thomas Burbacher, PhD
Methanol is being considered as a possible alternative fuel to decrease our dependence on non-renewable resources. Although methanol is a known teratogen in rodents, no developmental studies have been conducted in nonhuman primates. Nonhuman primates are the animal model of choice for methanol exposure studies due to their similarities with humans in methanol metabolism. To assess the developmental effects of prenatal methanol exposure, a long-term study was initiated using Macaca fascicularis monkeys. Results from this study have indicated that offspring from mothers exposed during pregnancy to 200, 600, or 1800 ppm methanol in air do not exhibit the typical preference for novelty when tested during infancy on an adaptation of the Fagan test. One hypothesis for these results is that methanol affects basic information processing. To test this hypothesis, a follow-up study was conducted on the methanol exposed and control monkeys at 4 to 6 years of age. A Simple and Choice Reaction Time test required the monkeys to place their hand on a home-bar, and then, after a variable length of time, respond as fast as they could to a button being illuminated by removing their hand from the home-bar and pushing the button. The length of time between the onset of the light and removal of the hand from the home-bar was considered the cognitive decision-making period or reaction time (RT). The length of time between removal of the hand from the home-bar and pushing the illuminated button was considered the movement time (MT). Initially, only one button was used (Simple Reaction Time), then 2 and 4 buttons (Choice Reaction Time). Data indicate Simple and Choice RTs and MTs of approximately consistent with previous reports, approximately 250 ms and 160ms, respectively. No methanol effects on Simple or Choice Reaction Time, movement time, or intraindividual variability were evident. (Supported by grant #90-9 from the Health Effects Institute and grant #ES06773 from NIEHS.)