Central nervous system effects of methyl methacrylate vapor

Inhalation experiments were conducted by exposing mature male Sprague-Dawley rats to methyl methacrylate (MMA) monomer vapor in air. The effects upon central neuronal activity associated with acute exposures of chloralose-urethanized rats to monomeric MMA vapor concentrations are summarized in this report. The most remarkable and readily apparent phenomenon was the depression of multiple-unit electrical activity in the lateral hypothalamus and ventral hippocampus of rats which were exposed to 400 ppm of MMA in air for 60 min. In marked contrast, recordings made from the parietal cortex, cerebellum, dorsal hippocampus, medial amygdala, ventral medial hypothalamus, anterior hypothalamus, septum, and mammillary body following comparable exposures showed insignificant changes in multiple-unit electrical activity.