Insulin-like growth factor I receptors and estrogen receptors colocalize in female rat brain
Section snippets
Animals
Female Wistar rats from our in-house breeding colony were kept in a 12:12 h light/dark cycle and studied when they were 40 days old. Animals received food and water ad libitum. They were handled according to European Union (86/609/EEC) guidelines on animal care. Special care was taken to minimize animal suffering and to reduce the number of animals used.
Inmunohistochemistry
All animals were killed by perfusion, under pentobarbital anesthesia, through the left cardiac ventricle when they were 40 days old. Animals
Results
ERα immunoreactivity had a neuronal localization and was observed exclusively in cell nuclei. Cell nuclei immunoreactive for ERα were observed in different brain regions, including the preoptic area, hypothalamus, hippocampus and cerebral cortex (Fig. 2). ERβ immunoreactivity was observed in neuronal cell nuclei and in the neuronal cytoplasm (Fig. 3, Fig. 4). Neurons in some areas such as the supraoptic nucleus (Fig. 3d) or the paraventricular nucleus (magnocellular neurons) showed an almost
Discussion
Our findings indicate that ERs colocalize with IGF-IR in different neuronal subpopulations in the female rat brain. In agreement with previous studies, we have found IGF-I receptor immunoreactivity in neurons and glial cells in the preoptic area, hypothalamus, hippocampus, cerebral cortex and cerebellum.1., 14., 32., 37., 51., 55., 96. The localization of ERα immunoreactivity in our study is also in agreement with previous reports showing that ERα has a neuronal and nuclear localization and it
Acknowledgements
We would like to thank Concha Bailon for excellent technical assistance in confocal microscopy, and Dr Sebastián Pons and the Instituto Cajal, CSIC antibodies service for their production of the IGF-IR mouse polyclonal antibody. This work was sponsored by Comunidad de Madrid (grant no. 08.5/0009/97), Dirección General de Enseñanza Superior e Investigación Cientı́fica (grant no. PM98-0110), and the Fundación Endocrinologı́a y Nutrición. G.P.C.-G. is a fellow from Colciencias,
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