Effect of Chlorpromazine and Pentobarbital Upon Shock- and Fear-Motivated Behavior in Mice

Abstract

A dose level of pentobarbital was determined with mice that would produce as much motor deficit as produced in the escape runway under 2 mg/kg of CPZ in Exp. I. This was done to control motor deficit due to CPZ in Exp. II and III. A specific blocking effect of CPZ upon escape and avoidance responses occurred in mice in comparison with pentobarbital and saline with pole-climbing (Exp. II) and with the shuttle-box (Exp. III). The CPZ action was much clearer with the shuttle-box than with pole-climbing during extinction. The discrepancy was discussed in relation to the types of the movement involved and the differential difficulty of the learning problems.