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: 585/3/805    most recent jphysiol.2007.144519v1 Services Email this article to a friend Similar articles in this journal 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 Hoyda, T. D. Articles by Ferguson, A. V. Search for Related Content PubMed PubMed Citation Articles by Hoyda, T. D. Articles by Ferguson, A. V. Related Collections Neuroscience

¹ Department of Physiology, Queen's University, 18 Stuart Street, Kingston, ON, Canada K7L 3N6
² University of Pennsylvania School of Medicine, Division of Endocrinology, Diabetes and Metabolism, 764 Clinical Research Building, 415 Curie Blvd, Philadelphia, PA 19104, USA

Adiponectin is an adipocyte derived hormone which acts in the brain to modulate energy homeostasis and autonomic function. The paraventricular nucleus of the hypothalamus (PVN) which plays a key role in controlling pituitary hormone secretion has been suggested to be a central target for adiponectin actions. A number of hormones produced by PVN neurons have been implicated in the regulation of energy homeostasis including oxytocin, corticotropin releasing hormone and thyrotropin releasing hormone. In the present study we investigated the role of adiponectin in controlling the excitability of magnocellular (MNC – oxytocin or vasopressin secreting) neurons within the PVN. Using RT-PCR techniques we have shown expression of both adiponectin receptors in the PVN. Patch clamp recordings from MNC neurons in hypothalamic slices have also identified mixed (27% hyperpolarization, 42% depolarization) effects of adiponectin in modulating the excitability of the majority of MNC neurons tested. These effects are maintained when cells are placed in synaptic isolation using tetrodotoxin. Additionally we combined electrophysiological recordings with single cell RT-PCR to examine the actions of adiponectin on MNC neurons which expressed oxytocin only, vasopressin only, or both oxytocin and vasopressin mRNA and assess the profile of receptor expression in these subgroups. Adiponectin was found to hyperpolarize 100% of oxytocin neurons tested (n = 6), while vasopressin cells, while all affected (n = 6), showed mixed responses. Further analysis indicates oxytocin neurons express both receptors (6/7) while vasopressin neurons express either both receptors (3/8) or one receptor (5/8). In contrast 6/6 oxytocin/vasopressin neurons were unaffected by adiponectin. Co-expressing oxytocin and vasopressin neurons express neither receptor (4/6). The results presented in this study suggest that adiponectin plays specific roles in controlling the excitability oxytocin secreting neurons, actions which correlate with the current literature showing increased oxytocin secretion in the obese population.

(Received 4 September 2007; accepted after revision 15 October 2007; first published online 18 October 2007)
Corresponding author A. V. Ferguson: Department of Physiology, Faculty of Life Sciences, Queen's University, Kingston, ON, Canada K7L 3N6. Email: avf{at}queensu.ca

This article has been cited by other articles:

				R. S. Ahima and M. A. Lazar Adipokines and the Peripheral and Neural Control of Energy Balance Mol. Endocrinol., May 1, 2008; 22(5): 1023 - 1031. [Abstract] [Full Text] [PDF]