A comparison of multiple 5-HT receptors in two tasks measuring impulsivity.
Impulsivity has often been assumed to be a unitary construct. However dissociable forms of impulsive behaviour may exist, each with distinct neurochemical underpinnings. To test this hypothesis, behavioural effects of three partially selective serotonergic (5-HT) ligands, ketanserin (5-HT2(A, C) receptor antagonist), SER-082 (5-HT2(C, B) receptor antagonist) and SB-270146-A (5-HT6 receptor antagonist) were compared in two tests of impulsivity. The five-choice serial reaction time task (5-csrtt) and a delayed reward task were chosen as they measure theoretically different types of impulsivity, behavioural inhibition versus choice preference for a delayed reward. Dissociation was seen between the effects of ketanserin, which decreased impulsivity in the 5-csrtt, but had no effect on the delayed reward task, and SER-082, which had no effect on the 5-csrtt, but decreased impulsive responding in the delayed reward task. SB-270146-A had no effect in either paradigm. The results suggest that the 5-csrtt and the delayed reward task do in fact measure different types of impulsive behaviour, which are at least partially neurochemically distinct.
Talpos
John C
JC
Department of Experimental Psychology, University of Cambridge, Cambridge, CB2 3EB, UK. jt286@cam.ac.uk
Wilkinson
Lawrence S
LS
Robbins
Trevor W
TW
D000818:Animals; D003216:Conditioning, Operant / Q000187:drug effects; D003627:Data Interpretation, Statistical; D005247:Feeding Behavior; D007175:Impulsive Behavior / Q000523:psychology*; D007650:Ketanserin / Q000494:pharmacology; D008297:Male; D051381:Rats; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology*; D012201:Reward; D012702:Serotonin Antagonists / Q000494:pharmacology
D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D007650:Ketanserin