Insulin-like growth factor I receptors and estrogen receptors colocalize in female rat brain

• Published in: Neuroscience 2000-01, Vol.99 (4), p.751-760
• Main Authors: Cardona-Gómez, G.P., DonCarlos, L., Garcia-Segura, L.M.
• Format: Article
• Language: English
• Subjects: Anatomy; Animals; Biological and medical sciences; Brain Chemistry; Central nervous system; Cerebral Cortex - chemistry; Cerebral Cortex - cytology; cortex; estradiol; Estrogen Receptor alpha; Estrogen Receptor beta; Female; Fluorescent Antibody Technique; Fundamental and applied biological sciences. Psychology; glia; hypothalamus; Hypothalamus - chemistry; Hypothalamus - cytology; insulin-like growth factor I; Neuroglia - chemistry; Neurons - chemistry; preoptic area; Preoptic Area - chemistry; Preoptic Area - cytology; Rats; Rats, Wistar; Receptor, IGF Type 1 - analysis; Receptors, Estrogen - analysis; Sex Factors; Vertebrates: nervous system and sense organs
• ISSN: 0306-4522; 1873-7544
• DOI: 10.1016/S0306-4522(00)00228-1

Several findings indicate that there is a close interaction between estrogen and insulin-like growth factor I in different brain regions. In adult brain, both estrogen and insulin-like growth factor I have co-ordinated effects in the regulation of neuroendocrine events, synaptic plasticity and neural response to injury. In this study we have qualitatively assessed whether estrogen receptors and insulin-like growth factor I receptor are colocalized in the same cells in the preoptic area, hypothalamus, hippocampus, cerebral cortex and cerebellum of female rat brain using confocal microscopy. Immunoreactivity for estrogen receptors α and β was colocalized with immunoreactivity for insulin-like growth factor I receptor in many neurons from the preoptic area, hypothalamus, hippocampus and cerebral cortex. Furthermore, estrogen receptor β and insulin-like growth factor I receptor immunoreactivities were colocalized in the Purkinje cells of the cerebellum. Colocalization of estrogen receptor β and insulin-like growth factor I receptor was also detected in cells with the morphology of astrocytes in all regions assessed. The co-expression of estrogen receptors and insulin-like growth factor I receptor in the same neurons may allow a cross-coupling of their signaling pathways. Furthermore, the colocalization of immunoreactivity for estrogen receptor β and insulin-like growth factor I receptor in glial cells suggests that glia may also play a role in the interactions of insulin-like growth factor I and estrogen in the rat brain. In conclusion, the co-expression of estrogen receptors and insulin-like growth factor I receptors in the same neural cells suggests that the co-ordinated actions of estrogen and insulin-like growth factor I in the brain may be integrated at the cellular level.