 |
The Journal of Neuroscience, June 2, 2004, 24(22):5091-5100; doi:10.1523/JNEUROSCI.0588-04.2004
Previous Article | Next Article 
Behavioral/Systems/Cognitive
Melanocortin 4 Receptor-Mediated Hyperphagia and Activation of Neuropeptide Y Expression in the Dorsomedial Hypothalamus during Lactation
Peilin Chen,1,2
Sarah M. Williams,1
Kevin L. Grove,1 and
M. Susan Smith1,2
1Division of Neuroscience, Oregon National Primate Research Center, and 2Department of Physiology and Pharmacology, Oregon Health and Science University, Beaverton, Oregon 97006-3499
In several hyperphagic models, including lactation, in which hypothalamic melanocortin signaling is reduced, a novel expression of NPY mRNA in the dorsomedial hypothalamus (DMH) has been observed, suggesting that melanocortin signaling and the induced NPY in the DMH may constitute unique neurocircuitry in mediating energy balance. Using lactating rats as a model, the present study first showed that in the DMH abundant -MSH and agouti-related protein fibers are in close apposition to NPY-positive cells. However, no NPY and MC4R (a melanocortin receptor) double-labeled neurons were observed. These data suggested that melanocortin input may synapse on presynaptic terminals that then synapse on DMH NPY cells. To study the function of DMH MC4Rs in energy balance, an MC3/4R-selective agonist, melanotan II (MTII), was injected bilaterally into the DMH. MTII injection significantly suppressed feeding induced by 24 hr fasting or suckling-induced hyperphagia. Furthermore, MTII treatment greatly attenuated suckling-induced NPY expression in the DMH. MTII treatment also stimulated uncoupling protein 1 activity in the brown adipose tissue of suckling female rats, indicative of increased sympathetic outflow. In summary, the present study demonstrated that the melanocortin system in the DMH not only plays an important role in inducing NPY expression in the DMH of lactating rats but also in regulating energy homeostasis, at least in part, by modulating appetite and energy expenditure.
Key words: NPY; MC4R; dorsomedial hypothalamus; lactation; food intake; UCP1
Received Feb 18, 2004;
revised April 13, 2004;
accepted April 16, 2004.
This article has been cited by other articles:

|
 |

|
 |
 
J. Xu, M. A. Kirigiti, K. L. Grove, and M. S. Smith
Regulation of Food Intake and Gonadotropin-Releasing Hormone/Luteinizing Hormone during Lactation: Role of Insulin and Leptin
Endocrinology,
September 1, 2009;
150(9):
4231 - 4240.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
L. Yang, K. A. Scott, J. Hyun, K. L. Tamashiro, N. Tray, T. H. Moran, and S. Bi
Role of Dorsomedial Hypothalamic Neuropeptide Y in Modulating Food Intake and Energy Balance
J. Neurosci.,
January 7, 2009;
29(1):
179 - 190.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J. Xu, M. A. Kirigiti, M. A. Cowley, K. L. Grove, and M. S. Smith
Suppression of Basal Spontaneous Gonadotropin-Releasing Hormone Neuronal Activity during Lactation: Role of Inhibitory Effects of Neuropeptide Y
Endocrinology,
January 1, 2009;
150(1):
333 - 340.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
C. T. Phillips and R. D. Palmiter
Role of Agouti-Related Protein-Expressing Neurons in Lactation
Endocrinology,
February 1, 2008;
149(2):
544 - 550.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M. Singh, R. A. Kesterson, M. M. Jacobs, J. M. Joers, J. C. Gore, and R. B. Emeson
Hyperphagia-mediated Obesity in Transgenic Mice Misexpressing the RNA-editing Enzyme ADAR2
J. Biol. Chem.,
August 3, 2007;
282(31):
22448 - 22459.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M. M. Glavas, S. E. Joachim, S. J. Draper, M. S. Smith, and K. L. Grove
Melanocortinergic Activation by Melanotan II Inhibits Feeding and Increases Uncoupling Protein 1 Messenger Ribonucleic Acid in the Developing Rat
Endocrinology,
July 1, 2007;
148(7):
3279 - 3287.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
S. Stanley, K. Wynne, B. McGowan, and S. Bloom
Hormonal Regulation of Food Intake
Physiol Rev,
October 1, 2005;
85(4):
1131 - 1158.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
K. Wynne, S. Stanley, B. McGowan, and S. Bloom
Appetite control
J. Endocrinol.,
February 1, 2005;
184(2):
291 - 318.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M. J. H. Kas, B. Tiesjema, G. van Dijk, K. M. Garner, G. S. Barsh, O. T. Brake, J. Verhaagen, and R. A. H. Adan
Induction of Brain Region-Specific Forms of Obesity by Agouti
J. Neurosci.,
November 10, 2004;
24(45):
10176 - 10181.
[Abstract]
[Full Text]
[PDF]
|
 |
|
|

|