Distribution of Thy-1 in human brain: immunofluorescence and absorption analyses with a monoclonal antibody.

A monoclonal antibody to human Thy-1 has been used to study the anatomical localization of Thy-1 in human brain and to quantitate the relative amounts of Thy-1 in different brain subregions. Quantitative absorption analyses using homogenates of carefully dissected brain subregions, together with an [125I]anti-immunoglobulin binding assay using brain homogenate as target, established that Thy-1 was present in large amounts throughout human brain, but the grey matter of cerebrum (cortical grey matter, caudate nucleus, putamen and thalamus) had 5-10 times as much Thy-1 as white matter. Grey matter of cerebellum (cerebellar cortex and dentate nucleus) also had higher amounts of Thy-1 than white matter, but the total amount of Thy-1 in cerebellum was less than in the cerebrum. Immunofluorescence studies gave interesting results and demonstrated in particular: (a) the outlining of some neuronal cell bodies and their processes (particularly the Purkinje cells of the cerebellar cortex) by spots of fluorescence; (b) staining of what appeared to be cell bodies of satellite cells in areas of grey matter; (c) granular staining in grey but not white matter; (d) staining of what appeared to be fibre tracts in the basal ganglia and thalamus, the tracts appearing duller than the surrounding grey matter of the nuclei; (e) staining of only some fibres in sciatic nerve; and (f) absence of staining of the adrenal gland.