+1 Recommend
1 collections
      • Record: found
      • Abstract: found
      • Article: found

      Hypothalamic Regulation of Mating-Induced Prolactin Release



      S. Karger AG

      Medial preoptic area, Mating, Prolactin

      Read this article at

          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.


          Lesions of the medial preoptic area (MPOA) induce nocturnal prolactin surges similar to those initiated by cervical stimulation (CS). These same lesions can abolish diurnal prolactin surges previously initiated by CS. Based on these results the MPOA has been suggested to contain two functionally dissimilar sets of neurons, one inhibitory for the nocturnal surge and the other stimulatory for the diurnal surge. The present study sought to demonstrate the existence of these neural elements by electrically stimulating the MPOA of conscious ovariectomized female rats during those times of day when these neurons would be most active. Serial blood samples were collected via cannula before, during and after the stimulation. Stimulation of the MPOA (01.00–05.00 h) on day 2 after CS inhibited the nocturnal surge of prolactin while sham MPOA stimulation of CS females did not disturb the nocturnal surge. MPOA stimulation in non-CS females had no effect upon prolactin secretion. Application of MPOA stimulation (15.00–19.00 h) to CS females also suppressed the diurnal surge of prolactin. Sham-stimulated CS females, however, secreted a diurnal surge peaking at 17.00 h. Basal prolactin levels were unaffected by MPOA stimulation (15.00–19.00 h) in non-CS females. The results from these experiments suggest that the MPOA contains neurons inhibitory for both the nocturnal and diurnal prolactin surges. In a further attempt to show a stimulatory role for the MPOA in prolactin regulation, MPOA stimulation was applied (15.00–19.00 h) to pentobarbital anesthetized non-CS females. Pentobarbital treatment allowed the MPOA stimulation to trigger two prolactin peaks, one at 16.00 h and the other at 19.00 h. The anesthesia did not alter prolactin release in the sham controls. From these stimulation studies and previous lesion experiments we conclude that the MPOA exerts monophasic inhibitory control over the nocturnal prolactin surge and biphasic, stimulatory and inhibitory control over the diurnal prolactin surge. CS must then act upon the MPOA to depress its inhibitory and activate its stimulatory elements for the secretion of the nocturnal and diurnal surges of prolactin to occur.

          Related collections

          Author and article information

          S. Karger AG
          28 March 2008
          : 38
          : 1
          : 12-16
          Department of Biological Science, Florida State University, Tallahassee, Fla., USA
          123859 Neuroendocrinology 1984;38:12–16
          © 1984 S. Karger AG, Basel

          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.

          Page count
          Pages: 5
          Original Paper


          Comment on this article