HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 291/3/R657    most recent 00560.2005v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Félix, B. Articles by Roman, C. Search for Related Content PubMed PubMed Citation Articles by Félix, B. Articles by Roman, C.

APPETITE, OBESITY, DIGESTION, AND METABOLISM

Leptin inhibits swallowing in rats

Bernadette Félix, André Jean, and Claude Roman

Université Paul Cézanne, Aix Marseille III, Faculté des Sciences et Techniques Campus St. Jérôme, Laboratoire de Physiologie Neurovégétative, Unité Mixte de Recherche Physiologie Neuro Végétative Centre National de la Recherche Scientifique-Institut National de la Recherche Agronomique-Université, Institut Fédératif de Recherche Jean Roche, Marseille cedex 20, France

Submitted 29 July 2005 ; accepted in final form 18 March 2006

Swallowing is under the control of premotoneurons located in the medullary solitary tract nucleus. Although rats with transected midbrain do not seek out food, they are able to ingest food present near the mouth, and acute food deprivation induces an increase in food intake. Leptin is a satiety signal that regulates feeding behavior. Because leptin receptors are found within the caudal brainstem, and because food intake is regulated in midbrain transected rats, this study tested the hypothesis that leptin is able to modify the activity of premotoneurons involved in swallowing. Leptin was microinjected at the subpostremal level of the medullary solitary tract nucleus in anesthetized Wistar rats. Electromyographic electrodes in sublingual muscles allowed recording of swallowing induced by stimulation of sensitive fibers of the superior laryngeal nerve. Repeated stimulation induced rhythmic swallowing. Microinjection of leptin (0.1 pg and 0.1 ng) in the swallowing center induced an inhibition of rhythmic swallowing (latency of <30 s) as shown by the reduced number and strength of electromyographic activities, which could last several minutes. The threshold of the leptin-induced inhibition was close to 0.1 pg. Interestingly, the inhibitory effect of leptin was not observed in leptin receptor-deficient Zucker rats. Here we show that, in Wistar rats, leptin already known to modulate the discharge of medullary solitary tract nucleus-sensitive neurons involved in satiety reflexes can also modify the activity of swallowing premotoneurons, thereby inhibiting an essential motor component of feeding behavior.

leptin; medullary solitary tract nucleus; swallowing; rat

This article has been cited by other articles:

				B. Bariohay, C. Tardivel, J. Pio, A. Jean, and B. Felix BDNF-TrkB signaling interacts with the GABAergic system to inhibit rhythmic swallowing in the rat Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2008; 295(4): R1050 - R1059. [Abstract] [Full Text] [PDF]