Effects of 5-HT2A receptor stimulation on the discrimination of durations by rats.
Behav Pharmacol
; 17(1): 51-9, 2006 Feb.
Article
de En
| MEDLINE
| ID: mdl-16377963
ABSTRACT
We recently found that rats' ability to discriminate durations of exteroceptive stimuli is disrupted by the non-selective 5-HT receptor agonist quipazine. Ketanserin reversed this effect, suggesting that the effect may be mediated by 5-HT2A receptors. Here, we report that the 5-HT2A/2C receptor agonist 2,5-dimethoxy-4-iodoamphetamine (DOI) also disrupts temporal discrimination, and that this effect can be reversed by ketanserin and the highly selective 5-HT2A receptor antagonist (+/-)2,3-dimethoxyphenyl-1-[2-(4-piperidine)-methanol] (MDL-100907). Twenty rats were trained to discriminate durations in a discrete-trials psychophysical procedure. In each 50-s trial, a light was presented for t seconds, following which two levers (A and B) were presented. A response on A was reinforced if t < 25 s, and a response on B if t > 25 s. Logistic psychometric curves were fitted to the proportional choice of B (%B) for derivation of timing indices [T50 time corresponding to %B = 50; Weber fraction (T75-T25)/2T50, where T75 and T25 are times corresponding to %B = 75 and 25, respectively]. DOI 0.25 mg kg (subcutaneous) significantly increased the Weber fraction and tended to increase T50. Ketanserin 2 mg kg (subcutaneous) did not alter either parameter, but completely antagonized the effects of DOI. Similarly, MDL-100907 0.5 and 1 mg kg (intraperitoneal) did not affect performance, but completely antagonized the effects of DOI. The results indicate that the mixed 5-HT2A/2C receptor agonist DOI disrupts temporal discrimination via stimulation of 5-HT2A receptors.
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Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Pipéridines
/
Antisérotonines
/
Perception du temps
/
Kétansérine
/
Agonistes des récepteurs de la sérotonine
/
Récepteur de la sérotonine de type 5-HT2A
/
Apprentissage discriminatif
/
Fluorobenzènes
/
Amphétamines
Type d'étude:
Prognostic_studies
Limites:
Animals
Langue:
En
Journal:
Behav Pharmacol
Sujet du journal:
CIENCIAS DO COMPORTAMENTO
/
FARMACOLOGIA
Année:
2006
Type de document:
Article
Pays d'affiliation:
Royaume-Uni