title: Combined autoradiography and formaldehyde-induced fluorescence methods for localization of radioactively labeled substances in relation to monoamine neurons.
abstract: A combined technique of formaldehyde-induced fluorescence (FIF) and autoradiography is described for the localization of radioactively labeled substances in relation to monoamine neurons. This method permits the simultaneous visualization of 3H-labeled steroid hormone or drug uptake sites and fluorescing monoamine neural elements (cell bodies, fiber projections, terminals) in the same tissue section. Thin frozen sections cut in a cryostat are freeze-dried, exposed to formaldehyde vapor at 80 degrees C, and carried through dry-mount autoradiography processing steps before fluorescence microscopy screening. Subsequent histological staining of sections and light microscopy are employed for conventional autoradiogram screening. With this procedure, 3H-estradiol and 3H-dihydrotestosterone are localized in various catecholamine (CA) neurons in the diencephalon and lower brain stem of the rat. Also, catecholaminergic as well as noncatecholaminergic sex steroid target neurons are seen to be innervated by CA terminals in various rat brain regions.
mesh_terms: D000818:Animals; D001345:Autoradiography / Q000379:methods*; D001921:Brain / Q000378:metabolism; D002395:Catecholamines / Q000378:metabolism*; D013196:Dihydrotestosterone / Q000378:metabolism; D004958:Estradiol / Q000378:metabolism; D005260:Female; D005557:Formaldehyde; D008297:Male; D008856:Microscopy, Fluorescence / Q000379:methods*; D009474:Neurons / Q000378:metabolism*; D051381:Rats
chemical_list: D002395:Catecholamines; D013196:Dihydrotestosterone; D005557:Formaldehyde; D004958:Estradiol