This Article Full Text Full Text (PDF) 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 PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Daftary, S. S. Articles by Gore, A. C. Search for Related Content PubMed PubMed Citation Articles by Daftary, S. S. Articles by Gore, A. C.

Developmental Changes in Hypothalamic Insulin-Like Growth Factor-1: Relationship to Gonadotropin-Releasing Hormone Neurons

Kastor Neurobiology of Aging Laboratories, Fishberg Research Center for Neurobiology, Brookdale Department of Geriatrics, Mount Sinai School of Medicine, New York, New York 10029

Address all correspondence and requests for reprints to: Andrea C. Gore, Ph.D., The University of Texas at Austin, Division of Pharmacology/Toxicology, 1 University Station, A1915, Austin, Texas 78712. E-mail: andrea.gore{at}mail.utexas.edu.

Reproductive development in vertebrates is controlled by changes in hypothalamic GnRH neurons and their inputs from other neurons and glia. One factor involved in the regulation of the GnRH system is the neurotrophic factor, IGF-1. To better understand the regulation of GnRH neurons by hypothalamic IGF-1, we quantified levels of IGF-1 mRNA in hypothalamic and preoptic regions containing GnRH cells, studied the effects of IGF-1 on GnRH gene expression, and examined the neuroanatomical relationship between GnRH neurons and hypothalamic IGF-1 in neonatal, peripubertal, and reproductively mature mice. Our results indicated that IGF-1 mRNA levels in the preoptic area and anterior hypothalamus peaked at postnatal day (P) 5, decreased through P20, and then increased through peripubertal and adult development. Second, IGF-1 had stimulatory effects on GnRH gene expression in explanted preoptic area-anterior hypothalamuses of P5 and peripubertal mice, with results varying by sex and duration of treatment. In contrast, IGF-1 had no effect or even inhibited GnRH gene expression in adult P60 mice. Third, GnRH perikarya coexpressed IGF-1, and this increased throughout sexual maturation. Taken together, the results suggest that IGF-1 can modulate GnRH neurons, that the sensitivity of GnRH neurons to IGF-1 changes developmentally, and that GnRH cells coexpress IGF-1.

This article has been cited by other articles:

				L. M. Garcia-Segura, B. Lorenz, and L. L DonCarlos The role of glia in the hypothalamus: implications for gonadal steroid feedback and reproductive neuroendocrine output Reproduction, April 1, 2008; 135(4): 419 - 429. [Abstract] [Full Text] [PDF]

				B. J Todd, G. S Fraley, A. C Peck, G. J Schwartz, and A. M Etgen Central Insulin-Like Growth Factor 1 Receptors Play Distinct Roles in the Control of Reproduction, Food Intake, and Body Weight in Female Rats Biol Reprod, September 1, 2007; 77(3): 492 - 503. [Abstract] [Full Text] [PDF]

				W. Yin and A. C Gore Neuroendocrine control of reproductive aging: roles of GnRH neurons. Reproduction, March 1, 2006; 131(3): 403 - 414. [Abstract] [Full Text] [PDF]

				H.-j. Li, C.-y. Ji, W. Wang, and Y.-h. Hu A Twin Study for Serum Leptin, Soluble Leptin Receptor, and Free Insulin-Like Growth Factor-I in Pubertal Females J. Clin. Endocrinol. Metab., June 1, 2005; 90(6): 3659 - 3664. [Abstract] [Full Text] [PDF]

				S. S. Daftary and A. C. Gore IGF-1 in the Brain as a Regulator of Reproductive Neuroendocrine Function Experimental Biology and Medicine, May 1, 2005; 230(5): 292 - 306. [Abstract] [Full Text] [PDF]

				J. D. Veldhuis, J. N. Roemmich, E. J. Richmond, A. D. Rogol, J. C. Lovejoy, M. Sheffield-Moore, N. Mauras, and C. Y. Bowers Endocrine Control of Body Composition in Infancy, Childhood, and Puberty Endocr. Rev., February 1, 2005; 26(1): 114 - 146. [Abstract] [Full Text] [PDF]

				A. Rose, P. Froment, V. Perrot, M. J. Quon, D. LeRoith, and J. Dupont The Luteinizing Hormone-releasing Hormone Inhibits the Anti-apoptotic Activity of Insulin-like Growth Factor-1 in Pituitary {alpha}T3 Cells by Protein Kinase C{alpha}-mediated Negative Regulation of Akt J. Biol. Chem., December 10, 2004; 279(50): 52500 - 52516. [Abstract] [Full Text] [PDF]

				A. C. Gore Gonadotropin-Releasing Hormone Neurons: Multiple Inputs, Multiple Outputs Endocrinology, September 1, 2004; 145(9): 4016 - 4017. [Full Text] [PDF]

				M.E. Wilson, K. Chikazawa, J. Fisher, D. Mook, and K.G. Gould Reduced Growth Hormone Secretion Prolongs Puberty But Does Not Delay the Developmental Increase in Luteinizing Hormone in the Absence of Gonadal Negative Feedback Biol Reprod, August 1, 2004; 71(2): 588 - 597. [Abstract] [Full Text] [PDF]

				G. Bienvenu, D. Seurin, P. Grellier, P. Froment, M. Baudrimont, P. Monget, Y. Le Bouc, and S. Babajko Insulin-Like Growth Factor Binding Protein-6 Transgenic Mice: Postnatal Growth, Brain Development, and Reproduction Abnormalities Endocrinology, May 1, 2004; 145(5): 2412 - 2420. [Abstract] [Full Text] [PDF]