Search

Made available in DSpace on 2022-04-28T18:57:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-01-01 Caffeine is the psychostimulant substance consumed in greatest quantities in the world. The repeated administration of psychostimulants can either decrease or increase the drug effect, inducing tolerance or sensitization, respectively, depending on administration procedure. Not only the dose and regimen, but also the environment where drug is administered, seem to modulate the changes in locomotor activity following repeated psychostimulant administration. The purpose of the present study was to examine the influence of the environmental context on caffeine-induced psychomotor stimulation following repeated administration of this drug. Our results showed that repeated caffeine induced psychomotor sensitization when drug injections were paired with the environment in which the animals were subsequently tested, whereas tolerance occurred when the animals received repeated caffeine in an environment different from that where the tests were performed. In conclusion, the present results demonstrated that the environmental context where caffeine is administered is a key factor modulating the adaptations of the organism to drug effects. Copyright © 2012 by Institute of Pharmacology Polish Academy of Sciences. Laboratory of Pharmacology School of Pharmaceutical Sciences Univ. Estadual Paulista-UNESP, Rod. Araraquara-Jaú Km 1, 14801-902, Araraquara, SP Interinstitutional Graduate Program in Physiological Sciences UFSCar/UNESP, Rod. Washington Luiz Km 235, 13565-905, São Carlos, SP Institute of Biomedical Sciences Federal University of Uberlândia (UFU), Av. Pará 1720, 38400-902, Uberlândia, MG Laboratory of Pharmacology School of Pharmaceutical Sciences Univ. Estadual Paulista-UNESP, Rod. Araraquara-Jaú Km 1, 14801-902, Araraquara, SP Interinstitutional Graduate Program in Physiological Sciences UFSCar/UNESP, Rod. Washington Luiz Km 235, 13565-905, São Carlos, SP

Made available in DSpace on 2013-09-27T14:53:45Z (GMT). No. of bitstreams: 1 WOS000291623600017.pdf: 397510 bytes, checksum: dd12033b1849c933defe8e898b98873f (MD5) Previous issue date: 2011-06-25 Made available in DSpace on 2013-09-30T18:08:02Z (GMT). No. of bitstreams: 1 WOS000291623600017.pdf: 397510 bytes, checksum: dd12033b1849c933defe8e898b98873f (MD5) Previous issue date: 2011-06-25 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:25:36Z No. of bitstreams: 1 WOS000291623600017.pdf: 397510 bytes, checksum: dd12033b1849c933defe8e898b98873f (MD5) Made available in DSpace on 2014-05-20T13:25:36Z (GMT). No. of bitstreams: 1 WOS000291623600017.pdf: 397510 bytes, checksum: dd12033b1849c933defe8e898b98873f (MD5) Previous issue date: 2011-06-25 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Caffeine is the psychostimulant drug most consumed in the world. This drug is present in food, beverages and medicines marketed for individuals of all ages. In spite of this, caffeine effects on adolescents are poorly understood. The aim of this study was to evaluate the differences on caffeine-induced locomotor stimulant or depressant effects in adolescent and adult rats. Adolescent (37-40 days old) or adult (70-74 days old) Wistar rats were tested for stimulant and depressant caffeine effects in two different experiments. The first was designed to evaluate the locomotor effect of caffeine in habituated rats. To this end, rats were previously habituated to test environment and had their locomotor activity registered following i.p. injections of vehicle or caffeine (3, 10, 30, 60 or 120 mg/kg). In the second experiment adolescent or adult rats were not habituated to the test environment and their locomotor activity was registered following i.p. injections of vehicle or caffeine (30, 60 or 120 mg/kg). In both experiments caffeine-induced a biphasic effect, with stimulation in small to moderate drug doses and no effect or locomotor depression in higher caffeine doses. Moreover, caffeine-induced locomotor stimulation was higher in adolescent than adult rats. Also, locomotor depression was only revealed in adult rats non-habituated to the test environment. These results suggest that adult and adolescent respond differently to caffeine indicating the need of more studies on the effects of caffeine in animals' models of adolescence. (C) 2011 Elsevier B.V. All rights reserved. Univ Estadual Paulista, Sch Pharmaceut Sci, Pharmacol Lab, UNESP, BR-14801902 Araraquara, SP, Brazil Universidade Federal de Uberlândia (UFU), Inst Biomed Sci, BR-38400902 Uberlandia, MG, Brazil Universidade Federal de São Carlos (UFSCar), Interinst Grad Program Physiol Sci, BR-13560 São Carlos, SP, Brazil Univ Estadual Paulista, Sch Pharmaceut Sci, Pharmacol Lab, UNESP, BR-14801902 Araraquara, SP, Brazil