Localization of metallothionein in the mammalian central nervous system

This review concerns the immunohistochemical localization of metallothionein (MT), a metal-binding protein, in the mammalian central nervous system (CNS). Expression of MT in the mammalian CNS is abundant. In the mouse brain, MT expression is found in some glial cells, whereas in the adult rat brain immunoreactivity varies from no expression at all to abundant reactivity throughout the whole brain. In primates and humans, MT expression is mainly found in astrocytes. Thus, MT expression in the mammalian CNS is found in the pia-arachnoid, ependymal cells and astrocytes. Cells expressing MTs can, in this way, supply essential metals to neurons and may protect neurons against toxic ions.