The effects of learning schedules on operant behavior in rats exposed to toluene were studied. The animals, 7 weeks of age, were divided into four groups and each group was trained on a different schedule. Continuous reinforcement (CRF), fixed-interval (FI), Sidman avoidance (SA) and negative fixed-interval (N-FI) schedules were used. Animals established the behavioral base line were exposed to 250, 500 and 750ppm of toluene and air for 4hr. The lever press behavior of the animals on each schedule after toluene exposure was compared with the behavior of those on each schedule after exposure to air alone.
The results are as follows: 1. CRF and SA schedules are easily learned and no significant difference is seen between the responses of subjects to air and toluene. 2. The FT schedule is that most strongly affected by toluene. The effects were dose dependent with increased lever presses and decreased acquisition rate during the initial stages of the test. 3. The N-FI schedule is slightly affected by toluene. A small decrease in avoidance rate is seen, but no change occurred in lever presses after toluene exposure.
The results suggest the importance of schedule selection when using operant behavioral techniques if one is to accurately evaluate the effects of toluene.