The effects of alpha-2 agonist, medetomidine and its antagonist, atipamezole on reaction and movement times in a visual choice reaction time task in monkeys

Alpha-2 adrenoceptor agonists have been shown to improve the working memory task performance of aged monkeys. Suggestions offered to explain this finding include improved short-term memory processing, slight sedation, and decreased distractiveness. Although sedation is evident at high doses, it may also contribute to the working memory task performance at low doses. The aim of the present work was to find out whether the positive effects of an alpha-2 agonist, medetomidine, on working memory performance could be explained by its sedative effects. This was accomplished by measuring the reaction and movement times of monkeys performing a visual choice reaction time task under the influence of medetomidine or its antagonist atipamezole. In the task a trial began with the monkey holding a central pad. After a short period one of two lateral light emitting diodes was turned on for 300 ms and the monkeys were trained to release the central bar and touch either of the bars, situated below the diodes, depending on the location of the stimulus. The reaction and movement times were significantly longer than on saline control only at the highest dose of medetomidine (10.0 micrograms/kg). At the lowest dose of atipamezole (0.01 mg/kg), the reaction times were significantly shorter than on saline control. The results of this study demonstrate that low doses of medetomidine, which have earlier been shown to improve working memory performance, do not induce sedation as measured by reaction and movement times.

Medienart:

Artikel

Erscheinungsjahr:

1997

Erschienen:

1997

Enthalten in:

Zur Gesamtaufnahme - volume:44

Enthalten in:

Brain research bulletin - 44(1997), 2 vom: 14., Seite 171-5

Sprache:

Englisch

Beteiligte Personen:

Rämä, P [VerfasserIn]
Linnankoski, I [VerfasserIn]
Carlson, S [VerfasserIn]

Themen:

03N9U5JAF6
Adrenergic alpha-Agonists
Adrenergic alpha-Antagonists
Atipamezole
Imidazoles
Journal Article
MR15E85MQM
Medetomidine
Research Support, Non-U.S. Gov't

Anmerkungen:

Date Completed 13.01.1998

Date Revised 19.07.2019

published: Print

Citation Status MEDLINE

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM09245089X