title: The pharmacological characterization of attentional processes using a two-lever choice reaction time task in rats.
abstract: Activating the noradrenergic and cholinergic systems is known to enhance attentional processes, while stimulating dopaminergic, serotonergic, and GABAergic systems suppresses them. The objective of the present study was to investigate the pharmacological characterization in the attentional processes of a two-lever choice reaction time (CRT) task using different centrally acting drugs. We designed seven parameters in this task: the correct response (CR) rate; error response rate; nonresponse (NR) rate; differential reinforcement of other behavior (DRO) responses; number of incorrect lever pressings during both the intertrial interval and DRO periods; the mean CRT of CR; and activity during 30 trials. The compounds produced different profiles at each dose. 1) Facilitative and disruptive effects on attentional processes occurred with changes in CRT alone. Scopolamine (0.1 mg/kg) and prazosin (0.3-1 mg/kg) prolonged the CRT, whereas methamphetamine (0.3 mg/kg) shortened the CRT. 2) Attentional deficits occurred with abnormal behavior showing premature response or perseverative behavior. Scopolamine (0.2-1 mg/kg), methamphetamine (3 mg/kg), delta(9)-tetrahydrocannabinol (10 mg/kg), and MK-801 (0.1-0.3 mg/kg) produced a marked increase in the number of total lever pressings. 3) Motor function deficits rather than attentional deficits occurred. 8-OH DPAT (1 mg/kg) and muscimol (1 mg/kg) produced a decrease in CR and an increase in NR with a marked decrease in activity and prolonged the CRT. Activating noradrenergic alpha(1) receptors was found to enhance the attentional processes, while blocking muscarinic receptors, alpha(1) receptors, and NMDA receptors, and stimulating cannabinoid receptors and the dopaminergic systems impaired the attentional processes in the two-lever CRT task.
authors.affiliation: Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Mishima
authors.forename: Megumi
authors.initials: M
authors.lastname: Fujii
authors.forename: Naoya
authors.initials: N
authors.lastname: Aoo
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Yoshikawa
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Fukue
authors.forename: Yoko
authors.initials: Y
authors.lastname: Honda
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Egashira
authors.forename: Katsunori
authors.initials: K
authors.lastname: Iwasaki
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Shoyama
authors.forename: Michihiro
authors.initials: M
authors.lastname: Fujiwara
mesh_terms: D000818:Animals; D001288:Attention / Q000187:drug effects* / Q000502:physiology; D002491:Central Nervous System Agents / Q000494:pharmacology*; D002755:Choice Behavior / Q000187:drug effects* / Q000502:physiology; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time / Q000187:drug effects* / Q000502:physiology
chemical_list: D002491:Central Nervous System Agents