A behavioral trait in rats which resembles some of the features of high-sensation seekers in man has been characterized. Given that the response to novelty is the basis of the definition of sensation-seeking, individual differences in reactivity to novelty have been studied on behavioral and biological levels. Certain individuals labeled as high responders (HR) as opposed to low responders (LR) have been shown to be highly reactive when exposed to a novel environment. These groups were investigated for free-choice responses to novel environments differing in complexity and aversiveness, and to other kinds of reinforcement, i.e. food and a drug. The HR rats appeared to seek novelty, variety and emotional stimulation. Only HR individuals have been found to be predisposed to drug-taking: they develop amphetamine self-administration whereas LR individuals do not. They also exhibit a higher sensitivity to the reinforcing properties of food. On a biological level, compared to LR rats, HR animals have an enhanced level of dopaminergic activity in the nucleus accumbens both under basal conditions or following a tail-pinch stress. HR and LR rats differ in reactivity of the corticotropic axis: HR rats exposed to a novel environment have a prolonged secretion of corticosterone compared to LR rats. The association of novelty, drug and food seeking in the same individual suggests that these characteristics share common processes. Differences in dopaminergic activity between HR and LR rats are consistent with results implicating these dopaminergic neurons in response to novelty and in drug-taking behavior. Given that rats self-administer corticosterone and that HR rats are more sensitive to the reinforcing properties of corticoste-roids, it could be speculated that HR rats seek novelty for the reinforcing action of corticosterone. These characteristics may be analogous to some for the features found in human high-sensation seekers and this animal model may be useful in determinating the biological basis of this human trait.

This content is only available via PDF.
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.