| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Pharmacology & Physiology, New Jersey Medical School (UMDNJ), Newark, NJ, USA
2 Universite Paris 7, CNRS UMR 7059, Paris, France
* To whom correspondence should be addressed. E-mail: routhvh{at}umdnj.edu.
Pharmacological manipulation of fatty acid metabolism in the hypothalamic arcuate nucleus (ARC) alters energy balance and glucose homeostasis. Thus, we tested the hypotheses that distinctive populations of ARC neurons are oleic-acid (OA) sensors that exhibit a glucose dependency, independent of whether some of these OA sensors are also glucose sensing neurons. We used patch clamp recordings to investigate the effects of OA on ARC neurons in brain slices from 14 - 21 d Sprague-Dawley (SD) rats. Additionally, we recorded spontaneous discharge rate in ARC neurons in 8 week old fed and fasted SD rats in vivo. Patch clamp studies showed that in 2.5 mM glucose 12 of 94 (13%) ARC neurons were excited by 2 µM OA (OA-excited or OAE neurons) while 6 of 94 (6%) were inhibited (OA-inhibited2.5 or OAI2.5 neurons). In contrast, in 0.1 mM glucose, OA inhibited 6 of 20 (30%) ARC neurons (OAI0.1 neurons); none were excited. None of the OAI0.1 neurons responded to OA in 2.5 mM glucose. Thus, OAI2.5 and OAI0.1 neurons are distinct. Similarly, in 7 of 20 fed rats (35%) the overall response was OAE-like, while in 3 of 20 (15%) it was OAI-like. In contrast, in fasted rats only OAI-like response were observed (3 of 15; 20%). There was minimal overlap between OA sensing neurons and glucose sensing neurons. In conclusion, OA regulated 3 distinct subpopulations of ARC neurons in a glucose-dependent fashion. These data suggest that an interaction between glucose and fatty acids regulates OA sensing in ARC neurons.
This article has been cited by other articles:
|
|
 |
|
  L. Kang, N. M. Sanders, A. A. Dunn-Meynell, L. D. Gaspers, V. H. Routh, A. P. Thomas, and B. E. Levin Prior hypoglycemia enhances glucose responsiveness in some ventromedial hypothalamic glucosensing neurons Am J Physiol Regulatory Integrative Comp Physiol, March 1, 2008; 294(3): R784 - R792. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Aja, L. E. Landree, A. M. Kleman, S. M. Medghalchi, A. Vadlamudi, J. M. McFadden, A. Aplasca, J. Hyun, E. Plummer, K. Daniels, et al. Pharmacological stimulation of brain carnitine palmitoyl-transferase-1 decreases food intake and body weight Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2008; 294(2): R352 - R361. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. Marty, M. Dallaporta, and B. Thorens Brain Glucose Sensing, Counterregulation, and Energy Homeostasis Physiology, August 1, 2007; 22(4): 241 - 251. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 X. Fioramonti, S. Contie, Z. Song, V. H. Routh, A. Lorsignol, and L. Penicaud Characterization of Glucosensing Neuron Subpopulations in the Arcuate Nucleus: Integration in Neuropeptide Y and Pro-Opio Melanocortin Networks? Diabetes, May 1, 2007; 56(5): 1219 - 1227. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. M. Sanders, G. J. Taborsky Jr., C. W. Wilkinson, W. Daumen, and D. P. Figlewicz Antecedent Hindbrain Glucoprivation Does Not Impair the Counterregulatory Response to Hypoglycemia Diabetes, January 1, 2007; 56(1): 217 - 223. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. E. Levin, L. Kang, N. M. Sanders, and A. A. Dunn-Meynell Role of Neuronal Glucosensing in the Regulation of Energy Homeostasis Diabetes, December 1, 2006; 55(Supplement_2): S122 - S130. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Migrenne, C. Cruciani-Guglielmacci, L. Kang, R. Wang, C. Rouch, A.-L. Lefevre, A. Ktorza, V. H. Routh, B. E. Levin, and C. Magnan Fatty Acid Signaling in the Hypothalamus and the Neural Control of Insulin Secretion Diabetes, December 1, 2006; 55(Supplement_2): S139 - S144. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. E. Levin Orexins: neuropeptides for all seasons and functions Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2006; 291(4): R885 - R888. [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
