Pubertal maturation modifies the regulation of insulin‐like growth factor‐I receptor signaling by estradiol in the rat prefrontal cortex

• Published in: Developmental neurobiology (Hoboken, N.J.) Vol. 68; no. 8; pp. 1018 - 1028
• Main Authors: Sanz, Amaya, Carrero, Paloma, Pernía, Olga, Garcia‐Segura, Luis M.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01-07-2008
• Subjects: adolescence; Akt; Animals; Blotting, Western; Estradiol - pharmacology; Estradiol - physiology; Estrogen Receptor alpha - physiology; estrogen receptors; Estrogens - pharmacology; Estrogens - physiology; Female; Glycogen Synthase Kinase 3 - metabolism; Glycogen Synthase Kinase 3 beta; glycogen synthase kinase 3β; Immunohistochemistry; Injections, Intraperitoneal; Insulin-Like Growth Factor I - physiology; MAP Kinase Signaling System - drug effects; MAP Kinase Signaling System - physiology; neuronal plasticity; Neurons - drug effects; Neurons - physiology; Ovariectomy - methods; Phosphorylation - drug effects; Prefrontal Cortex - drug effects; Prefrontal Cortex - physiology; Proto-Oncogene Proteins c-akt - metabolism; Rats; Rats, Wistar; Receptor, IGF Type 1 - physiology; Sexual Maturation - drug effects; Sexual Maturation - physiology; Signal Transduction - drug effects; Signal Transduction - physiology; Synapses - drug effects; Synapses - physiology
• ISSN: 1932-8451; 1932-846X
• DOI: 10.1002/dneu.20641

The transition from adolescence to adulthood is accompanied by substantial plastic modifications in the cerebral cortex, including changes in the growth and retraction of neuronal processes and in the rate of synaptic formation and neuronal loss. Some of these plastic changes are prevented in female rats by prepubertal ovariectomy. The ovarian hormone estradiol modulates neuronal differentiation and survival and these effects are in part mediated by the interaction with insulin‐like growth factor‐I (IGF‐I). In this study, we have explored whether the activation by estradiol of some components of IGF‐I receptor signaling is altered in the prefrontal cortex during puberty. Estradiol administration to rats ovariectomized after puberty resulted, 24 h after the hormonal administration, in a sustained phosphorylation of Akt and glycogen synthase kinase 3β in the prefrontal cortex. However, this hormonal effect was not observed in animals ovariectomized before puberty. These findings suggest that during pubertal maturation there is a programming by ovarian hormones of the future regulatory actions of estradiol on IGF‐I receptor signaling in the prefrontal cortex. The modification in the regulation of IGF‐I receptor signaling by estradiol during pubertal maturation may have implications for the developmental changes occurring in the prefrontal cortex in the transition from adolescence to adulthood. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2008.