title: Plasticity of synaptopodin and the spine apparatus organelle in the rat fascia dentata following entorhinal cortex lesion.
abstract: Synaptopodin is an actin-associated molecule essential for the formation of a spine apparatus in telencephalic spines. To study whether synaptopodin and the spine apparatus organelle are regulated under conditions of lesion-induced plasticity, synaptopodin and the spine apparatus were analyzed in granule cells of the rat fascia dentata following entorhinal denervation. Confocal microscopy was employed to quantify layer-specific changes in synaptopodin-immunoreactive puncta densities. Electron microscopy was used to quantify layer-specific changes in spine apparatus organelles. Within the denervated middle and outer molecular layers, the layers of deafferentation-induced spine loss, synaptogenesis, and spinogenesis, the density of synaptopodin puncta and the number of spine apparatuses decreased by 4 days postlesion and slowly recovered in parallel with spinogenesis by 180 days postlesion. Within the nondenervated inner molecular layer, the zone without deafferentation-induced spine loss, a rapid loss of synaptopodin puncta and spine apparatuses was also observed. In this layer, spine apparatus densities recovered by 14 days postlesion, in parallel with plastic remodeling at the synaptic level and the postlesional recovery of granule cell activity. These data demonstrate layer-specific changes in the distribution of synaptopodin and the spine apparatus organelle following partial denervation of granule cells: in the layer of spine loss, spine apparatus densities follow spine densities; in the layer of spine maintenance, however, spine apparatus densities appear to be regulated by other signals.
authors.affiliation: Institute of Clinical Neuroanatomy, J.W. Goethe-University, D-60590 Frankfurt/Main, Germany. t.deller@em.uni-frankfurt.de
authors.forename: Thomas
authors.initials: T
authors.lastname: Deller
authors.forename: Carlos
authors.initials: C
authors.lastname: Bas Orth
authors.forename: Andreas
authors.initials: A
authors.lastname: Vlachos
authors.forename: Tobias
authors.initials: T
authors.lastname: Merten
authors.forename: Domenico
authors.initials: D
authors.lastname: Del Turco
authors.forename: Doris
authors.initials: D
authors.lastname: Dehn
authors.forename: Peter
authors.initials: P
authors.lastname: Mundel
authors.forename: Michael
authors.initials: M
authors.lastname: Frotscher
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D003599:Cytoskeleton / Q000378:metabolism / Q000648:ultrastructure; D049229:Dendritic Spines / Q000378:metabolism* / Q000648:ultrastructure; D003714:Denervation; D018891:Dentate Gyrus / Q000378:metabolism* / Q000648:ultrastructure; D004721:Endoplasmic Reticulum / Q000378:metabolism / Q000648:ultrastructure; D018728:Entorhinal Cortex / Q000293:injuries / Q000378:metabolism* / Q000648:ultrastructure; D007150:Immunohistochemistry; D008297:Male; D008840:Microfilament Proteins / Q000378:metabolism*; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D009410:Nerve Degeneration / Q000378:metabolism / Q000503:physiopathology; D009473:Neuronal Plasticity / Q000502:physiology*; D015388:Organelles / Q000378:metabolism / Q000648:ultrastructure; D019580:Perforant Pathway / Q000378:metabolism* / Q000648:ultrastructure; D017729:Presynaptic Terminals / Q000378:metabolism / Q000648:ultrastructure; D051381:Rats; D017207:Rats, Sprague-Dawley; D013569:Synapses / Q000378:metabolism / Q000648:ultrastructure; D009435:Synaptic Transmission / Q000502:physiology
chemical_list: D008840:Microfilament Proteins; C503969:Synpo protein, rat