Experimental studies on the role of DA in motivation methodological considerations

EXPERIMENTAL STUDIES ON THE ROLE OF DA IN MOTIVATION METHODOLOGICAL CONSIDERATIONS 

Although complementary in principle, experimental and correlative approaches have often provided apparently contrasting results. In the specific case of the role of DA in motivation this might be due to the kind of experimental approach utilized as a basis for comparing experimental and correlative evidence. 

Studies on the role of DA have taken advantage of the availability of 6-OHDA as a lesioning tool of DA neurons (Ungerstedt, 1968). 

Soon after the formalization of the original anhedonia hypothesis, however, Phillips and Fibiger (1979) reported that neuroleptics reduce responding also when given under extinction moreover, Gray and Wise (1980) observed that DA receptor blockers impaired 

As a result of these early studies, therefore, four main hypotheses were considered to explain the effect of DA-receptor blockers on instrumental behavior (1) Blunting of the rewarding properties of primary reinforcers (original anhedonia hypothesis)  

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