Pigeons were trained to respond under three conditional discrimination procedures; 1) a fixed-consecutive-number procedure with (FCN 8-SD) and without (FCN 8) an added external discriminative stimulus, 2) a delayed matching-to-sample (DMTS) procedure using 0-sec, 2-sec and 8-sec delay intervals, and 3) a repeated acquisition of behavioral chains (RA) procedure using a four-link response chain with three stimulus keys. The atypical neuroleleptic agent molindone decreased accuracy under the FCN 8 at doses that had no effect on accuracy under the FCN 8-SD. Under the DMTS procedure, molindone-induced decreases in accuracy were directly related to the delay interval, with the largest relative decrements obtained at the 8-sec delay and the smallest at the 0-sec delay. Under the RA procedure, molindone decreased accuracy at doses that had little or no effect on the number of correct responses emitted. Relative to control values, molindone-induced decreases in accuracy were smallest under the DMTS and FCN 8-SD procedures and largest under the FCN 8 and RA procedures. The differential effects obtained with molindone under each of these procedures illustrate the need to employ a variety of assays when determining the behavioral actions of neuroleptics. In addition, this battery of behavioral tests may provide a useful tool for assessing the different neurochemical actions of neuroleptic compounds.
Bibliographical noteFunding Information:
This work was partially supported by U.S. Public Service Grant MH42343 awarded to M. Picker and L. A. Dykstra. K. Berens was supported by U.S. Public Service Grant DA02717 awarded to T. Thompson and J. Cleary. A. Oliveto was the recipient of Predoctoral Fellowship DA05314 and L. A. Dykstra the recipient of Research Scientist Award K05DA00033. A preliminary report of this work was presented at the 72nd Annual Meeting of the Federation of American Societies for Experimental Biology, Las Vegas, NV 1988.
- Conditional discriminations
- Delayed matching-to-sample
- Repeated acquisition