Abstract
The effects of subchronic inhalation exposure to toluene (80 ppm, for 4 weeks, 5 days/week, 6 h/day) was studied on spatial learning (postexposure days 3-6) and memory (postexposure day 14) using a water maze, on spontaneous and apomorphine-induced (1 mg/kg, subcutaneously (s.c.)) locomotor activity (postexposyre day 17) and on the binding parameters of the dopamine D2 agonist S(-)[N-propyl-3H(N)]propylnorapomorphine ([H]NPA) in membrane preparations of the neostriatum of the rat. Toluene treatment was found to cause a statistically significant impairment in acquisition and retention of the spatial learning task. Furthermore, toluene significantly increased (2-fold) apomorphine-induced locomotion and caused a trend for a 50-60% increase in motility without any significant effect on rearing. Spontaneous locomotion, motility and rearing were not affected by toluene. Toluene treatment produced a significant 30-40% increase in the Bmax values of [3H]NPA and a trend for a 20-30% increase in the KD values. These results indicate that subchronic exposure to toluene in low concentrations causes a slight but persistent deficit in spatial learning and memory, a persistent increase in dopamine-mediated locomotor activity and an increase in the number of dopamine D2 receptors in the rat.
Original language | English (US) |
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Pages (from-to) | 223-232 |
Number of pages | 10 |
Journal | Toxicology |
Volume | 77 |
Issue number | 3 |
DOIs | |
State | Published - Mar 19 1993 |
Keywords
- Apomorphine
- Dopamine receptor
- Locomotion
- N-propylnorapomorphine
- Organic solvent
- Spatial learning
ASJC Scopus subject areas
- Toxicology