Winsauer, P.J., Moerschbaecher, J.M. & Roussell, A.M. (2008).
Differential antagonism of cocaine self-administration and cocaine-induced
disruptions of learning by haloperidol in rhesus monkeys.
Journal of the Experimental Analysis of Behavior, 89, 225-246.
Six rhesus monkeys responding under a three-component multiple schedule
were administered haloperidol to determine its effects on cocaine self-administration
and on cocaineÕs disruptive effects on the repeated acquisition and performance
of response chains. In the absence of haloperidol, 0.0032 - 0.032 mg/kg/infusion
of cocaine increased response rate and the number of infusions
in the self-administration component when compared to saline administration,
whereas 0.1 - 0.32 mg/kg/infusion decreased response rate and the number
of infusions. When compared to saline administration, the two lowest
infusion doses of cocaine had little or no effect on responding in the
acquisition and performance components; however, higher infusion doses
of cocaine dose-dependently decreased response rate in these components.
In addition, the higher doses of cocaine also increased the percentage
of errors in the acquisition and performance components. Pretreatment
with haloperidol (0.0032 or 0.01 mg/kg, i.m.) antagonized the effects
of low doses of cocaine on the number of infusions in the self-administration
component, whereas only the 0.01-mg/kg dose antagonized the effects
of high doses of cocaine on the number of infusions. Neither dose of
haloperidol antagonized the rate-decreasing effects of cocaine on
responding in the acquisition and performance components significantly;
the highest dose of haloperidol alone decreased rates of responding in
each component. Antagonism of cocaineÕs error-increasing effects by
haloperidol was only evident at one dose of cocaine (0.032 mg/kg/infusion),
and was more complete in the performance components than in
the acquisition components. Together, these data show the
limited suitability of haloperidol for selectively antagonizing
cocaine self-administration in the context of a multiple schedule
involving transition behavior, and show the lack of uniform
antagonism across operant behaviors.
Key words: self-administration, repeated acquisition, multiple schedule, cocaine, haloperidol, key press, rhesus monkeys