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This Article Full Text Full Text (PDF) All Versions of this Article: 295/4/R1050    most recent 90407.2008v1 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 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 Bariohay, B. Articles by Félix, B. Search for Related Content PubMed PubMed Citation Articles by Bariohay, B. Articles by Félix, B.

APPETITE, OBESITY, AND DIGESTION

BDNF-TrkB signaling interacts with the GABAergic system to inhibit rhythmic swallowing in the rat

Centre de Recherche en Neurobiologie-Neurophysiologie de Marseille, CRN2M, Université de la Méditerranée, Université Paul Cézanne, Centre National de la Recherche Scientifique Unité Mixte de Recherche 6231, USC-Institut National de la Recherche Agronomique 2027, Département de Physiologie NeuroVégétative, Campus de St Jérôme, Marseille, France

Submitted 7 May 2008 ; accepted in final form 5 August 2008

Brain-derived neurotrophic factor (BDNF) acts as an anorexigenic factor in the dorsal vagal complex (DVC) of the adult rat brain stem. The DVC contains the premotoneurons controlling swallowing, a motor component of feeding behavior. Although rats with transected midbrain do not seek out food, they are able to swallow and to ingest food. Because BDNF and tropomyosin-related kinase B (TrkB) receptors are expressed in the DVC, this study hypothesized that BDNF could modify the activity of premotoneurons involved in swallowing. Repetitive electrical stimulation of the superior laryngeal nerve (SLN) induces rhythmic swallowing that can be recorded with electromyographic electrodes inserted in sublingual muscles. We show that a microinjection of BDNF in the swallowing network induced a rapid, transient, and dose-dependant inhibition of rhythmic swallowing. This BDNF effect appeared to be mediated via TrkB activation, since it no longer occurred when TrkB receptors were antagonized by K-252a. Interestingly, swallowing was inhibited when subthreshold doses of BDNF and GABA were coinjected, suggesting a synergistic interaction between these two signaling substances. Moreover, BDNF no longer had an inhibitory effect on swallowing when coinjected with bicuculline, a GABA_A receptor antagonist. This blockade of BDNF inhibitory effect on swallowing was reversible, since it reappeared when BDNF was injected 15 min after bicuculline. Finally, we show that stimulation of SLN induced a decrease in BDNF protein within the DVC. Together, our results strongly suggest that BDNF inhibits swallowing via modulation of the GABAergic signaling within the central pattern generator of swallowing.

brain-derived neurotrophic factor; -aminobutyric acid; medullary solitary tract nucleus; dorsal vagal complex; feeding behavior

This article has been cited by other articles:

				E. F. Bailey A tasty morsel: the role of the dorsal vagal complex in the regulation of food intake and swallowing. Focus on "BDNF/TrkB signaling interacts with GABAergic system to inhibit rhythmic swallowing in the rat," by Bariohay et al. Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2008; 295(4): R1048 - R1049. [Full Text] [PDF]