Confocal scanning laser microscopy of steroid receptors in the brain

This chapter describes the features of confocal scanning laser microscopy (CSLM) and its applications in steroid receptor research. In CSLM images, out-of-focus blur is essentially absent. An important feature of CSLM is the possibility to construct three-dimensional images by making serial optical sections. Because CSLM is designed primarily for detection of fluorescently labeled probes, primary or secondary antibodies, conjugated to a fluorochrome, are used. The procedure for double labeling is basically the same as for single labeling. The CSLM technique can contribute significantly to the understanding of the mechanisms underlying the modulation of brain function by steroid receptors. Steroid receptors are present in low concentrations in cultured cells. Confocal scanning electron microscopy in combination with immunofluorescent labeling is a powerful technique with which to study the localization of steroid receptors in cells and tissues. Because most confocal microscopes are equipped with a dual detection system, CSLM is particularly useful for double-labeling studies. In this way, the distribution of steroid receptors can be compared to that of other cell components.