Interaction of gonadal steroids and growth factors in brain sex differentiation
Maria C. Fernandez-Galaz, Arpad Parducz, Frederick Naftolin, Ingacio Torres-Aleman, and Lids M. Garcia-Segura (Spain, Hungary, and USA)
Sex hormones have developmental trophic actions on ne urons and glial cells and activational effects in the adult brain. It has been proposed that sex steroids may interact with peptide trophic factors to induce part of their biological effects in the nervous system. The first evidence of such an interaction was provided by Toran-Allerand et al (Brain Res 1980; 184: 517-524), showing that in explant cultures of fetal rodent hy- polhalamus, estrogen and insulin have synergistic effects on neurite growth, an effect probably mediated by insulin-like growth factor-1 receptors. Recent data indicate that estrogen and insulin-like growth factor-! signaling pathways interact on hypothalamic neurons to regulate survival and differentia- tion and that sex steroids interact with a variety of different trophic signals in vivo to regulate neuroendocrine events. These findings suggest that trophic factors may be involved in the genesis of sex differences in the developing brain and in the maintenance of a sexually differentiated brain function in the adult.
Bimed Rev 1997; 7: 67-74
Rccive d for publication 5 April 1997 and accepted 3 June 1997
Correspondence and reprint requests to Dr Luis M. Garcia-Segura, Institute Cajal, CSIC, Av. Dr. Arce 37, E-28002 Madrid, Spain, Tel: 34 (1) 585 4729, Fax: 34 (1) 585 4754