| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
ARTICLES |
Division of Neuroscience, Oregon Regional Primate Research Center, Department of Physiology and Pharmacology, Oregon Health Sciences University, Beaverton, Oregon 97006
Address all correspondence and requests for reprints to: Dr. M. Susan Smith, Division of Neuroscience, Oregon Regional Primate Research Center, 505 NW 185th Avenue, Beaverton, Oregon 97006. E-mail: smithsu{at}ohsu.edu
Neuropeptide Y (NPY) neurons in the arcuate nucleus of the hypothalamus (ARH) have been shown to play an important role in modulating LH secretion. One mechanism by which the ARH NPY system may regulate LH secretion is by modulating GnRH neuronal function. Thus, the present study examined whether the ARH NPY system provided direct input to GnRH cell bodies in the preoptic area (POA), as well as to their nerve terminals in the median eminence (ME). The possible involvement of the NPY Y1 receptor subtype in mediating the effects of NPY was also investigated. Lactating rats were used in these studies because they have increased hypothalamic NPY content, especially in the ARH/ME areas, making it easier to detect NPY fibers and terminals. The anterograde tracer, Phaseolus vulgaris leucoagglutinin (PHA-L), was iontophoresed into the ARH of lactating rats; and triple-label immunofluorescence was performed, with the aid of confocal microscopy, to visualize NPY, PHA-L, and GnRH. GnRH cell bodies were found scattered throughout the organum vasculosum laminae terminalis (OVLT)/POA region, and NPY/PHA-L double-labeled fibers were found in very close proximity to numerous GnRH perikarya. In the ME, double-labeled NPY/PHA-L fibers were found in the inner and external zones, and they were found in close proximity to GnRH neuronal fibers. Using a NPY Y1 specific antibody, double-label immunofluorescence was performed to examine whether the Y1 receptor subtype was expressed in GnRH neurons. No convincing Y1-positive staining was found in GnRH cell bodies in the OVLT/POA region. However, abundant Y1-positive fiber and cell staining were observed throughout the region, and Y1-positive fibers were found in close apposition to GnRH cell bodies. In contrast, numerous GnRH nerve fibers and terminals in both the OVLT and ME were colocalized with Y1-positive staining. The results of this study suggest that ARH NPY neurons come in close contact with GnRH neurons and may provide direct input to both GnRH cell bodies in the POA region and to their nerve terminals in the ME. The Y1 receptor subtype may be directly involved in NPY modulation of GnRH secretion from its nerve terminals.
This article has been cited by other articles:
 |
|
 |
|
  W. Huang, M. Acosta-Martinez, T. H. Horton, and J. E. Levine Fasting-induced suppression of LH secretion does not require activation of ATP-sensitive potassium channels Am J Physiol Endocrinol Metab, December 1, 2008; 295(6): E1439 - E1446. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Gonzalez-Martinez, C. De Mees, Q. Douhard, C. Szpirer, and J. Bakker Absence of Gonadotropin-Releasing Hormone 1 and Kiss1 Activation in {alpha}-Fetoprotein Knockout Mice: Prenatal Estrogens Defeminize the Potential to Show Preovulatory Luteinizing Hormone Surges Endocrinology, May 1, 2008; 149(5): 2333 - 2340. [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]
|
|
|
|
|
|
S. Lin, E.-J. D. Lin, D. Boey, N. J. Lee, K. Slack, M. J. During, A. Sainsbury, and H. Herzog Fasting Inhibits the Growth and Reproductive Axes via Distinct Y2 and Y4 Receptor-Mediated Pathways Endocrinology, May 1, 2007; 148(5): 2056 - 2065. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Komatsu, T. Chiba, H. Yamaza, K. To, H. Toyama, Y. Higami, and I. Shimokawa Effect of leptin on hypothalamic gene expression in calorie-restricted rats. J. Gerontol. A Biol. Sci. Med. Sci., September 1, 2006; 61(9): 890 - 898. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. D. Veldhuis, J. N. Roemmich, E. J. Richmond, and C. Y. Bowers Somatotropic and Gonadotropic Axes Linkages in Infancy, Childhood, and the Puberty-Adult Transition Endocr. Rev., April 1, 2006; 27(2): 101 - 140. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
X. Q. Xiao, K. L. Grove, S. Y. Lau, S. McWeeney, and M. S. Smith Deoxyribonucleic Acid Microarray Analysis of Gene Expression Pattern in the Arcuate Nucleus/Ventromedial Nucleus of Hypothalamus during Lactation Endocrinology, October 1, 2005; 146(10): 4391 - 4398. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. J P Ebling The neuroendocrine timing of puberty Reproduction, June 1, 2005; 129(6): 675 - 683. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
I. J. Clarke, K. Backholer, and A. J. Tilbrook Y2 Receptor-Selective Agonist Delays the Estrogen-Induced Luteinizing Hormone Surge in Ovariectomized Ewes, but Y1-Receptor-Selective Agonist Stimulates Voluntary Food Intake Endocrinology, February 1, 2005; 146(2): 769 - 775. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. Chen, S. M. Williams, K. L. Grove, and M. S. Smith Melanocortin 4 Receptor-Mediated Hyperphagia and Activation of Neuropeptide Y Expression in the Dorsomedial Hypothalamus during Lactation J. Neurosci., June 2, 2004; 24(22): 5091 - 5100. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. M. Escobar, S. J. Krajewski, T. Sandoval-Guzman, M. L. Voytko, and N. E. Rance Neuropeptide Y Gene Expression Is Increased in the Hypothalamus of Older Women J. Clin. Endocrinol. Metab., May 1, 2004; 89(5): 2338 - 2343. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Gonzalez-Martinez, T. Madigou, E. Mananos, J. M. Cerda-Reverter, S. Zanuy, O. Kah, and J. A. Munoz-Cueto Cloning and Expression of Gonadotropin-Releasing Hormone Receptor in the Brain and Pituitary of the European Sea Bass: An In Situ Hybridization Study Biol Reprod, May 1, 2004; 70(5): 1380 - 1391. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Chen and M. S. Smith Regulation of Hypothalamic Neuropeptide Y Messenger Ribonucleic Acid Expression during Lactation: Role of Prolactin Endocrinology, February 1, 2004; 145(2): 823 - 829. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. H. Mills, R. K. Sohn, and P. E Micevych Estrogen-Induced {micro}-Opioid Receptor Internalization in the Medial Preoptic Nucleus Is Mediated via Neuropeptide Y-Y1 Receptor Activation in the Arcuate Nucleus of Female Rats J. Neurosci., January 28, 2004; 24(4): 947 - 955. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. F. Turi, Z. Liposits, S. M. Moenter, C. Fekete, and E. Hrabovszky Origin of Neuropeptide Y-Containing Afferents to Gonadotropin-Releasing Hormone Neurons in Male Mice Endocrinology, November 1, 2003; 144(11): 4967 - 4974. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. W. Hill and J. E. Levine Abnormal Response of the Neuropeptide Y-Deficient Mouse Reproductive Axis to Food Deprivation But Not Lactation Endocrinology, May 1, 2003; 144(5): 1780 - 1786. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. E. Campbell, K. L. Grove, and M. S. Smith Gonadotropin-Releasing Hormone Neurons Coexpress Orexin 1 Receptor Immunoreactivity and Receive Direct Contacts by Orexin Fibers Endocrinology, April 1, 2003; 144(4): 1542 - 1548. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. E. Campbell, M. S. Smith, S. E. Allen, B. E. Grayson, J. M. H. ffrench-Mullen, and K. L. Grove Orexin Neurons Express a Functional Pancreatic Polypeptide Y4 Receptor J. Neurosci., February 15, 2003; 23(4): 1487 - 1497. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Watanobe Leptin directly acts within the hypothalamus to stimulate gonadotropin-releasing hormone secretion in vivo in rats J. Physiol., November 15, 2002; 545(1): 255 - 268. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H.-W. Tsai and S. J. Legan Loss of Luteinizing Hormone Surges Induced by Chronic Estradiol Is Associated with Decreased Activation of Gonadotropin-Releasing Hormone Neurons Biol Reprod, April 1, 2002; 66(4): 1104 - 1110. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. P. Goldstone, U. A. Unmehopa, S. R. Bloom, and D. F. Swaab Hypothalamic NPY and Agouti-Related Protein Are Increased in Human Illness But Not in Prader-Willi Syndrome and Other Obese Subjects J. Clin. Endocrinol. Metab., February 1, 2002; 87(2): 927 - 937. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Knauf, V. Prevot, G. B. Stefano, G. Mortreux, J.-C. Beauvillain, and D. Croix Evidence for a Spontaneous Nitric Oxide Release from the Rat Median Eminence: Influence on Gonadotropin-Releasing Hormone Release Endocrinology, June 1, 2001; 142(6): 2343 - 2350. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Ichimaru, Y. Mori, and H. Okamura A Possible Role of Neuropeptide Y as a Mediator of Undernutrition to the Hypothalamic Gonadotropin-Releasing Hormone Pulse Generator in Goats Endocrinology, June 1, 2001; 142(6): 2489 - 2498. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Takatsu, H. Matsumoto, T. Ohtaki, S. Kumano, C. Kitada, H. Onda, O. Nishimura, and M. Fujino Distribution of Galanin-Like Peptide in the Rat Brain Endocrinology, April 1, 2001; 142(4): 1626 - 1634. [Abstract] [Full Text]
|
|
|
|
 |
|
 R. C. Speth, M. S. Smith, and K. L. Grove Lactation decreases angiotensinogen mRNA expression in the midcaudal arcuate nucleus of the rat brain Am J Physiol Regulatory Integrative Comp Physiol, April 1, 2001; 280(4): R1169 - R1176. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Xu, J. H. Urban, J. W. Hill, and J. E. Levine Regulation of Hypothalamic Neuropeptide Y Y1 Receptor Gene Expression during the Estrous Cycle: Role of Progesterone Receptors Endocrinology, September 1, 2000; 141(9): 3319 - 3327. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Mizuno, M. Gearing, and E. Terasawa The Role of Neuropeptide Y in the Progesterone-Induced Luteinizing Hormone-Releasing Hormone Surge in Vivo in Ovariectomized Female Rhesus Monkeys Endocrinology, May 1, 2000; 141(5): 1772 - 1779. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Endocrinology | Endocrine Reviews | J. Clin. End. & Metab. |
| Molecular Endocrinology | Recent Prog. Horm. Res. | All Endocrine Journals |
