Autoradiography of benzodiazepine receptor binding in the central nervous system of the normal C57BL6J mouse.

[3H]flunitrazepam has been used as a photoaffinity label for the specific, clonazepam-displaceable 1,4-benzodiazepine binding sites in sections of normal C57BL6J mouse brain and spinal cord. Binding was visualized by light microscope autoradiography and quantified by a simple microdensitometric procedure. Specific flunitrazepam binding was seen to be highest in the colliculi, cerebral cortex, hippocampal formation, interpeduncular nucleus, mamillary body, hypothalamus, olfactory tubercle, and in the molecular layer and deep nuclei of the cerebellum. The distribution of specific flunitrazepam binding sites in mouse brain and spinal cord is discussed in terms of the known actions of the benzodiazepines.