文档介绍：The Journal of Neuroscience, October 1995, 75(10): 6403-6416 lmmunochemical Identification and Subcellular Distribution of the’ <x,~ Subunits of Brain Calcium Channels Ruth E. Westenbroek,’ Takashi Sakurai,’ Elicia M. Elliott,’ Johannes W. Hell,’ Terry V. B. Starr,2 Terry P. Snutch: and William A. Catterall’ 1 Department of Pharmacology, University of Washington, Seattle, Washington 98195 and 2Biotechnology Laboratory and Departments of Zoology and Neuroscience, University of British Columbia, Vancouver, British Columbia, Canada V6T 123 A site-directed anti-peptide antibody (Al) directed against the (Y, subunit of class A calcium channels ((Y,~) recognized a protein of approximately 190-200 kDa in im- munoblot and immunoprecipitation analyses of rat brain glycoproteins. Calcium channels recognized by Al were distributed throughout the brain with a high concen- tration in the cerebellum. Calcium channels having (Y,,, sub- units were concentrated in presynaptic terminals making synapses on cell bodies and on dendritic shafts and spines of many classes of neurons and were especially prominent in the synapses of the parallel fibers of cerebellar granule cells on Purkinje neurons where their localization in pre- synaptic terminals was confirmed by double labeling with the synaptic membrane protein syntaxin or the microin- jetted postsynaptic marker Neurobiotin. They were present in lower density in the surface membrane of dendrites of most major classes of neurons. There was substantial la- beling of Purkinje cell bodies, but less intense staining of the cell bodies of hippocampal pyramidal neurons, layer V pyramidal neurons in the dorsal cortex, and most other classes of neurons in the forebrain and cerebellum. Scat- tered cell bodies elsewhere in the brain were labeled at low levels. These results define a unique pattern of localization of class A calcium channels in the cell bodies, dendrites, and presynaptic terminals of most central ne