Effects of subchronic exposure to toluene on working and reference memory in rats.
Rats that had inhaled 600 ppm of toluene vapor 24 h a day for 50 days after weaning at 3 weeks of age were trained in a radial-arm maze with a 4-out-of-8 baiting procedure, and their performance based upon reference and/or working memory was compared with that of air-exposed control animals during the early stage of acquisition. Pharmacological challenge testing was also conducted after completing a total of 48 training sessions; the effects of scopolamine and methylscopolamine on the maze performance were measured after acute i.p. administration to determine the long-lasting effects of toluene exposure. During the acquisition stage, toluene-exposed rats made a significantly smaller number of reference memory errors (entries into "never-baited" arms) and total arm entries than the control rats. No significant effects of exposure were observed for working memory errors (reentries into "already-entered" arms). During the pharmacological challenge testing, only scopolamine increased both types of errors significantly. No significant differences due to toluene exposure were revealed.
Miyagawa
M
M
Department of Industrial Physiology, National Institute of Industrial Health, Kawasaki, Japan.
Honma
T
T
Sato
M
M
D000818:Animals; D004347:Drug Interactions; D008297:Male; D018782:Maze Learning / Q000187:drug effects*; D008568:Memory / Q000187:drug effects*; D019832:N-Methylscopolamine; D010276:Parasympatholytics / Q000494:pharmacology; D051381:Rats; D011916:Rats, Inbred F344; D012601:Scopolamine / Q000494:pharmacology; D012602:Scopolamine Derivatives / Q000494:pharmacology; D014050:Toluene / Q000494:pharmacology*
D010276:Parasympatholytics; D012602:Scopolamine Derivatives; D014050:Toluene; D012601:Scopolamine; D019832:N-Methylscopolamine