Haloperidol attenuates rewarding and aversively conditioned suppression of saccharin solution intake: reevaluation of the anhedonia hypothesis of dopamine blocking.
The dopamine (DA) antagonist, haloperidol, affected the conditioned suppression of a saccharin solution intake (the conditioned stimulus, CS) induced by amphetamine (AMPH) and lithium chloride (LiCl) unconditioned stimuli (USs). Four experiments showed that (a) haloperidol by itself did not reduce saccharin solution intake. (b) When haloperidol was injected between the CS and the US, the conditioned suppression was attenuated; however, (c) this did not occur when haloperidol was injected after the US, indicating that haloperidol affected the perception of the US. (d) This attenuation was found with both rewarding AMPH and aversive LiCl treatments, indicating that the valence of the US was unimportant. Thus, the so-called "anhedonia response" might be due to weakening of US impact. A general salient-stimulus hypothesis was proposed, with the anhedonia hypothesis of DA blocking as its subset.
Huang
Andrew Chih Wei
AC
Department of Psychology, National Chung Cheng University, Chia-Yi, Taiwan, Republic of China. d8832005@ccunix.ccu.edu.tw
Hsiao
Sigmund
S
D000661:Amphetamine / Q000494:pharmacology; D000818:Animals; D018692:Antimanic Agents / Q000494:pharmacology; D000697:Central Nervous System Stimulants / Q000494:pharmacology; D003214:Conditioning, Classical; D004193:Discrimination Learning; D018492:Dopamine Antagonists / Q000494:pharmacology*; D005247:Feeding Behavior; D006220:Haloperidol / Q000494:pharmacology*; D018021:Lithium Chloride / Q000494:pharmacology; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D011954:Receptors, Dopamine / Q000502:physiology*; D012439:Saccharin; D013549:Sweetening Agents
D018692:Antimanic Agents; D000697:Central Nervous System Stimulants; D018492:Dopamine Antagonists; D011954:Receptors, Dopamine; D013549:Sweetening Agents; D000661:Amphetamine; D012439:Saccharin; D018021:Lithium Chloride; D006220:Haloperidol