题名：Localization of EphA4 in axon terminals and dendritic spines of adult rat hippocampus.
作者：Tremblay ME, Riad M, Bouvier D, Murai KK, Pasquale EB, Descarries L, Doucet G.
来源：J Comp Neurol[IF=3.855]. 2007 Apr 10;501(5):691-702.
摘要： Marie-ve Tremblay 1, Mustapha Riad 1, David Bouvier 1, Keith K. Murai 2, Elena B. Pasquale 3 4, Laurent Descarries 1, Guy Doucet 1 *
1Dpartement de pathologie et biologie cellulaire and Groupe de recherche sur le systme nerveux central, Universit de Montral, Montral, Qubec, Canada H3C 3J7
2Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, McGill University Health Centre, Montreal General Hospital, Montral, Qubec, Canada H3G 1A4
3The Burnham Institute for Medical Research, La Jolla, California 92037
4Pathology Department, University of California, San Diego, La Jolla, California 92093
email: Guy Doucet (firstname.lastname@example.org)
*Correspondence to Guy Doucet, Dpartement de pathologie et biologie cellulaire and Groupe de recherche sur le systme nerveux central, Universit de Montral, Montral, Qubec, Canada H3C 3J7
Canadian Institutes for Health Research (CIHR); Grant Number: MOP-57704
National Sciences and Engineering Research Council of Canada (NSERC)
Eph ?synaptogenesis ?excitatory synapse ?immunocytochemistry ?electron microscopy
Eph receptors and their ephrin ligands assume various roles during central nervous system development. Several of these proteins are also expressed in the mature brain, and notably in the hippocampus, where EphA4 and ephrins have been shown to influence dendritic spine morphology and long-term potentiation (LTP). To examine the cellular and subcellular localization of EphA4 in adult rat ventral hippocampus, we used light and electron microscopic immunocytochemistry with a specific polyclonal antibody against EphA4. After immunoperoxidase labeling, EphA4 immunoreactivity was found to be enriched in the neuropil layers of CA1, CA3, and dentate gyrus. In all examined layers of these regions, myelinated axons, small astrocytic leaflets, unmyelinated axons, dendritic spines, and axon terminals were immunolabeled in increasing order of frequency. Neuronal cell bodies and dendritic branches were immunonegative. EphA4-labeled dendritic spines and axon terminals corresponded to 9-19% and 25-40% of the total number of spines and axon terminals, respectively. Most labeled spines were innervated by unlabeled terminals, but synaptic contacts between two labeled elements were seen. The vast majority of synaptic junctions made by labeled elements was asymmetrical and displayed features of excitatory synapses. Immunogold labeling of EphA4 was located mostly on the plasma membrane of axons, dendritic spines, and axon terminals, supporting its availability for surface interactions with ephrins. The dual preferential labeling of EphA4 on pre- or postsynaptic specializations of excitatory synapses in adult rat hippocampus is consistent with roles for this receptor in synaptic plasticity and LTP. J. Comp. Neurol. 501:691-702, 2007. ? 2007 Wiley-Liss, Inc. 3: