Ca2+/calmodulin-dependent protein kinase II in the rat cerebellum: an immunohistochemical study with monoclonal antibodies specific to either alpha or beta subunit.

Monoclonal antibodies specific to either alpha or beta subunit of Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) of the rat brain were produced and the distribution of each subunit in the rat cerebellum was examined immunohistochemically. Each antibody detected solely the corresponding subunit in immunoblot analysis of crude homogenates of the rat forebrain and cerebellum, and purified CaM kinase II from the rat forebrain. Immunoreactivity for alpha subunit was present selectively in Purkinje cells: perikarya, dendrites with their spines, axons and their terminal-like structures in the cerebellar cortex, cerebellar nuclei and lateral vestibular nucleus. Many of these alpha subunit-immunoreactive axons from the cerebellum were traced only through the inferior cerebellar peduncle. beta Subunit was detected in perikarya and dendrites of a limited number of Purkinje cells, many granule cells and neurons in the cerebellar nuclei. Thus, different distributions of alpha and beta subunits of CaM kinase II in the cerebellum were demonstrated.