Disruptive effects of prefeeding and haloperidol administration on multiple measures of food-maintained behavior in rats
ABSTRACT Four rats responded under a choice reaction-time procedure. At the beginning of each trial, the rats were required to hold down a center lever for a variable duration, release it following a high- or low-pitched tone, and press either a left or right lever, conditionally on the tone. Correct choices were reinforced with a probability of .95 or .05 under blinking or static houselights, respectively. After performance stabilized, disruptive effects of free access to food pellets prior to sessions (prefeeding) and intraperitoneal injection of haloperidol were examined on multiple behavioral measures (i.e., the number of trials completed, percent of correct responses, and reaction time). Resistance to prefeeding depended on the probability of food delivery for the number of trials completed and reaction time. Resistance to haloperidol, on the other hand, was not systematically affected by the probability of food delivery for all dependent measures.
Article: Reaction time responding in rats.[Show abstract] [Hide abstract]
ABSTRACT: The use of reaction time has a great tradition in the field of human information processing research. In animal research the use of reaction time test paradigms is mainly limited to two research fields: the role of the striatum in movement initiation; and aging. It was discussed that reaction time responding can be regarded as "single behavior", this term was used to indicate that only one behavioral category is measured, allowing a better analysis of brain-behavior relationships. Reaction time studies investigating the role of the striatum in motor functions revealed that the initiation of a behavioral response is dependent on the interaction of different neurotransmitters (viz. dopamine, glutamate, GABA). Studies in which lesions were made in different brain structures suggested that motor initiation is dependent on defined brain structures (e.g. medialldorsal striatum, prefrontal cortex). It was concluded that the use of reaction time measures can indeed be a powerful tool in studying brain-behavior relationships. However, there are some methodological constraints with respect to the assessment of reaction time in rats, as was tried to exemplify by the experiments described in the present paper. On the one hand one should try to control for behavioral characteristics of rats that may affect the validity of the parameter reaction time. On the other hand, the mean value of reaction time should be in the range of what has been reported in man. Although these criteria were not always met in several studies, it was concluded that reaction time can be validly assessed in rats. Finally, it was discussed that the use of reaction time may go beyond studies that investigate the role of the basal ganglia in motor output. Since response latency is a direct measure of information processing this parameter may provide insight into basic elements of cognition. Based on the significance of reaction times in human studies the use of this dependent variable in rats may provide a fruitful approach in studying brain-behavior relationships in cognitive functions.Neuroscience & Biobehavioral Reviews 11/1998; 22(6):847-64. DOI:10.1016/S0149-7634(98)00013-X · 10.28 Impact Factor
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ABSTRACT: In this study the behavioral consequences of intra-striatal haloperidol and scopolamine injections were examined using a reaction time task. Haloperidol was found to increase the response time of the rats and had a modest effect on the motor components of the task. The manner in which haloperidol affected the response time distribution suggested that this drug affected attentional functions. Scopolamine did not affect the reaction time or motor performance in the reaction time task. However, a clear decrease in the number of completed trials and an increase in anticipatory responses was observed. At present no ready explanation could be given for the behavioral effects of scopolamine. The present data suggest that although dopamine and acetylcholine are intimately related in the striatal network and have been supposed to have antagonistic functions, the behavioral consequences of blockade of dopamine and acetylcholine receptors are dissimilar.European Neuropsychopharmacology 01/2000; 9(6):523-31. DOI:10.1016/S0924-977X(99)00036-X · 5.40 Impact Factor
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ABSTRACT: The attentional and motor-disruptive effects of low doses of haloperidol were studied in a sustained attention task performed by rats. Five separate groups (n = 7 or 8) of rats were trained to react to a 0.125-sec visual stimulus by executing a nose-poke response within 3 sec of stimulus presentation. Each group of rats received its own dose (0.0, 0.02, 0.04, 0.08 or 0.12 mg/kg) of haloperidol daily for 3 months, and from the 1st week onward dose-effects on reaction time were quite stable across time. Haloperidol treatment disrupted the sustained attention task performance by decreasing the number of behavior-initiated stimulus presentations, decreasing the number of reinforcers earned, increasing the proportion of errors of omission and increasing reaction time to the target stimulus. Testing of challenge drugs began after 23 days of haloperidol treatment. Scopolamine (0.1 and 0.2 mg/kg), benztropine (1.0, 3.0 and 6.0 mg/kg) and d-amphetamine (0.25, 0.5, 1.0 and 2.0 mg/kg) ameliorated haloperidol-induced reaction time slowing, whereas only benztropine and amphetamine lessened haloperidol-induced errors of omission. The 2.0-mg/kg dose of amphetamine by itself produced a significant increase in errors of omission without affecting reaction time. Haloperidol effectively normalized this amphetamine-induced disruption in attention. The results are consistent with a dopaminergic involvement in the expression of both attention and motor processes.Journal of Pharmacology and Experimental Therapeutics 01/1996; 275(3):1090-8. · 3.86 Impact Factor