Pharmacological studies of performance on the free-operant psychophysical procedure

• Published in: Behavioural processes 2013-05, Vol.95, p.71-89
• Main Authors: Body, S., Cheung, T.H.C., Valencia-Torres, L., Olarte-Sánchez, C.M., Fone, K.C.F., Bradshaw, C.M., Szabadi, E.
• Format: Article
• Language: English
• Subjects: 5-HT receptors; agonists; Animal ethology; Animals; antagonists; Behavior, Animal - drug effects; Biological and medical sciences; Conditioning, Operant - drug effects; Corpus striatum; Corpus Striatum - drug effects; cortex; dopamine; Dopamine Agonists - pharmacology; Dopamine Antagonists - pharmacology; Dopamine receptors; Female; Free-operant psychophysical procedure; Fundamental and applied biological sciences. Psychology; General aspects; Interval timing; Prefrontal cortex; Prefrontal Cortex - drug effects; Psychology. Psychoanalysis. Psychiatry; Quinolinic Acid - toxicity; Rats; Rats, Wistar; receptors; serotonin; Serotonin Antagonists - pharmacology
• ISSN: 0376-6357; 1872-8308
• DOI: 10.1016/j.beproc.2013.02.004

► The authors’ research on timing in the free-operant psychophysical procedure (FOPP) is reviewed. ► 5-Hydroxytryptamine (5-HT1A, 5-HT2A) and dopamine (D1-like, D2-like) agonists disrupt timing. ► Effects of endogenous 5-HT may be mediated by 5-HT2A and endogenous dopamine by D1-like receptors. ► New data are presented on the effects of prefrontal cortical and striatal lesions. ► Ventral striatal lesions abolished the effects of a D1-like receptor agonist on timing in the FOPP. In the free-operant psychophysical procedure (FOPP), reinforcement is provided intermittently for responding on lever A in the first half and lever B in the second half of a trial. Temporal differentiation is measured from the psychometric function (percent responding on B, %B, versus time from trial onset, t), the index of timing being T50, the value of t at %B=50. T50 is reduced by acute treatment with 5-hydroxytryptamine (5-HT1A, 5-HT2A) and dopamine (D1-like, D2-like) receptor agonists. The effects of the agonists can be reversed by the respective antagonists of these receptors. Evidence is reviewed suggesting that the effect of endogenous 5-HT is mediated by 5-HT2A receptors and the effect of endogenous dopamine by D1-like receptors. Data are presented on the effects of lesions of the prefrontal cortex and corpus striatum on the sensitivity of performance on the FOPP to D1-like and D2-like receptor agonists. Lesions of the nucleus accumbens, but not the dorsal striatum or prefrontal cortex, attenuated the effects of a D1-like receptor agonist, 6-chloro-2,3,4,5-tetrahydro-1-phenyl-1H-3-benzazepine [SKF-81297], but not a D2-like receptor agonist, quinpirole, on T50. The results indicate that a population of D1-like receptors in the ventral striatum may contribute to the control of timing performance on the FOPP. This article is part of a Special Issue entitled: SQAB 2012.