Effect of 8-OH-DPAT on temporal discrimination following central 5-hydroxytryptamine depletion
| Autor: | Elemer Szabadi, M.-Y. Ho, Simon C. Body, C. M. Bradshaw, Sirous Mobini, T.-J. Chiang |
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| Rok vydání: | 2002 |
| Předmět: |
Agonist
Serotonin medicine.medical_specialty medicine.drug_class Dopamine 5 7-Dihydroxytryptamine Clinical Biochemistry Population Receptors Presynaptic Toxicology Biochemistry Norepinephrine Behavioral Neuroscience chemistry.chemical_compound Discrimination Psychological Serotonin Agents Postsynaptic potential Internal medicine medicine Animals Rats Wistar Receptor education Biological Psychiatry 5-HT receptor Brain Chemistry Pharmacology 8-Hydroxy-2-(di-n-propylamino)tetralin education.field_of_study 8-OH-DPAT Hydroxyindoleacetic Acid Rats Serotonin Receptor Agonists Surgery Endocrinology chemistry Synapses Time Perception Conditioning Operant Female Psychology |
| Zdroj: | Pharmacology Biochemistry and Behavior. 71:787-793 |
| ISSN: | 0091-3057 |
| DOI: | 10.1016/s0091-3057(01)00674-8 |
| Popis: | The 5-hydroxytryptamine (5-HT)(1A) receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) alters performance in discrete-trials timing schedules. 5-HT(1A) receptors occur both presynaptically and postsynaptically, but it is not known which receptor population mediates the effects of 8-OH-DPAT on timing. Rats received intra-raphe injections of 5,7-dihydroxytryptamine (n=16) or sham lesions (n=14). They were trained in a discrete-trials psychophysical procedure in which levers were presented at a predetermined time after the onset of each trial (2.5, 7.5,., 47.5 s). A response on lever A was reinforced if lever presentation occurred25 s after trial onset; a response on lever B was reinforced if lever presentation occurred25 s after trial onset. After 70 preliminary sessions, the rats received 8-OH-DPAT (25, 50, 100, 200 microg kg(-1) sc) and saline vehicle. The percentage of responses on lever B (%B) increased as a function of time from trial onset. Under the baseline (vehicle-treatment) condition, performance did not differ between the two groups. 8-OH-DPAT did not alter the indifference point (time corresponding to %B=50%), but dose-dependently increased the Weber fraction in both groups. Forebrain concentrations of 5-HT and 5-HIAA in the lesioned group were approximately 10% of control levels. The results suggest that the effect of 8-OH-DPAT on performance on discrete-trials timing schedules is mediated by postsynaptic 5-HT(1A) receptors. |
| Databáze: | OpenAIRE |
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