Alpha isoform of calcium-calmodulin dependent protein kinase II (CAM II kinase-alpha) restricted to excitatory synapses in the CA1 region of rat hippocampus.
Pre-embedding immunoperoxidase staining for CAM II kinase-alpha and post-embedding immunogold staining for glutamate and GABA, were used to reveal the subcellular distribution of CAM II kinase-alpha at transmitter-characterized synapses in the CA1 region of rat hippocampus. Immunoelectron microscopy showed that the majority of CAM II kinase-alpha-immunostained neuronal profiles were dendritic spines presumably derived from pyramidal cells. CAM II kinase-alpha immunoreactivity was mainly localized in postsynatic densities associated with glutamatergic axon terminals. No CAM II kinase-alpha immunoreactivity was detected in GABA-immunoreactive profiles or at GABAergic synapses. This study provides morphological evidence that CAM II kinase-alpha is involved only in excitatory neuronal transmission in the CA1 region. The enzyme is unlikely to be involved in plasticity at GABA synapses.
Liu
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Department of Anatomy and Neurobiology, College of Medicine, University of California, Irvine 92697, USA.
Jones
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EG
D000818:Animals; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000032:analysis*; D005260:Female; D018698:Glutamic Acid / Q000032:analysis*; D006624:Hippocampus / Q000737:chemistry / Q000201:enzymology*; D007124:Immunoenzyme Techniques; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000032:analysis*; D017774:Long-Term Potentiation; D008297:Male; D016253:Microscopy, Immunoelectron; D051381:Rats; D017208:Rats, Wistar; D013569:Synapses / Q000737:chemistry / Q000201:enzymology*; D016610:Tissue Embedding; D005680:gamma-Aminobutyric Acid / Q000032:analysis*
D007527:Isoenzymes; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases