We examined the effects of diminished serotonin (5-hydroxytryptamine, 5-HT) levels on the postnatal development of striatal tachykinin and enkephalin neuropeptide systems. Neonatal rats received intracisternal injection of vehicle or the 5-HT neurotoxin 5,7-dihydroxytryptamine (5,7-DHT; 100 pg) on postnatal day 2 followed by sacrifice 1–29 days later. Monoamine analysis by high-performance liquid chromatography with electrochemical detection revealed a drastic reduction of midbrain 5-HT levels, but not norepinephrine or dopamine, as early as 1 day and extending to 29 days following 5,7-DHT injection. Striatal preprotachykinin (PPT) mRNA levels were significantly increased 8 days following injection. However, PPT mRNA amounts failed to remain up-regulated, falling back to or below control levels during the second and third weeks following injection. By day 29, striatal PPT mRNA had normalized to control levels even though 5-HT amounts were still markedly reduced. Throughout the entire time course, striatal preproenkephalin mRNA levels did not significantly differ from control levels. These results suggest that striatal tachykinin, but not enkephalin, neurons may be transiently sensitive to lowered 5-HT neurotransmission during postnatal development.

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.