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| Mean descent latency for conditioning trials as a function of Groups. Pair: Paired; Unp: Unpaired. Error bars represent SEMs.
Source publication
Repeated pairings of a neutral context and the effects of haloperidol give rise to conditioned catalepsy when the context is subsequently presented in a drug-free test. In order to confirm whether this response is based on Pavlovian processes, we conducted two experiments involving two manipulations that affect conditioning intensity in classical c...
Context in source publication
Context 1
... contrast, a reduction of conditioned catalepsy was observed in the group with the longer ISI, since extinction of the CR was faster for the Pair/90 group than the Pair/20 group. The fact that no differences appeared between the two matched groups on the first test trial is logical if we consider the strong catalepsy effect induced by haloperidol during conditioning regardless of the ISI used (Figure 3); in fact, although the concentration of haloperidol in the brain starts to decline 15 min after administration, the effect on the motor response persists for up to 6 h (e.g., Zetler and Baumann, 1985). ...
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The neuronal underpinning of learning cause-and-effect associations in the adolescent brain remains poorly understood. Two fundamental forms of associative learning are Pavlovian (classical) conditioning, where a stimulus is followed by an outcome, and operant (instrumental) conditioning, where outcome is contingent on action execution. Both forms...
Citations
... The results confirmed that when animals in the Hal/Sal group (that received haloperidol before context exposure) were submitted to the catalepsy bar test in a drug-free trial, conditioned catalepsy was evident compared to the Sal/Hal and Sal/Sal groups (that received haloperidol 20 min after context exposure or did not receive the drug, respectively). This conditioned catalepsy response has been consistently obtained using different procedures [15,24]. However, when following the catalepsy test bar, spontaneous locomotor activity of the animals was recorded for a prolonged period (10 min), it appeared a significant higher number of rapid movements, and an increase in activity time in the Hal/Sal as compared to the control groups. ...
... For example, Bazyan et al. [25] injected the drug 30, 60, or 120 min before the test and reported a catalepsy effect for all the intervals, but found a positive correlation between the intensity of catalepsy response and the duration of the interval. In our experiment, the use of a 20-min interval between drug administration and the different tests is determined by previous studies carried out in our laboratory, in which this time interval was effective in inducing both conditioned catalepsy and a conditioned increase of locomotor activity [22][23][24]. ...
Previous research has revealed a high degree of complexity of the conditioned response that appears after associating a context with the effects of the dopaminergic antagonist haloperidol. Specifically, when a drug-free test is performed in the presence of the context, conditioned catalepsy is observed. However, if the test is extended over time, the opposite effect occurs, namely, a conditioned increase in locomotor activity. In this paper, we present the results of an experiment with rats that received repeated administration of haloperidol or saline before or after exposure to the context. Next, a drug-free test was performed to evaluate catalepsy and spontaneous locomotor activity. The results revealed, on the one hand, the expected conditioned response of catalepsy for those animals that received the drug prior to context exposure during conditioning. However, for the same group, an analysis of locomotor activity for an extended period of ten minutes after registering catalepsy revealed an increase in general activity and more faster movements compared to the control groups. These results are interpreted considering the possible temporal dynamics of the conditioned response that could induce changes in dopaminergic transmission responsible for the observed changes in locomotor activity.
