Continuities between outer nuclear membrane and the rough endoplasmic reticulum increase in hippocampal neurons during seizure-induced protein synthesis.
The ultrastructure of rat dentate gyrus granule cells was examined during, and near the termination of, a period of lesion-induced recurrent limbic seizure activity which has previously been demonstrated to stimulate dramatic changes in the biosynthetic activities of these neurons. In animals sacrificed 5 h postlesion (or 3.5 h following seizure onset) the rough endoplasmic reticulum (RER) appeared more extensive than in controls and there was a large, statistically significant increase in the number of continuities between the RER and the outer nuclear membrane (ONM). By 11 h postlesion the latter index had returned to control values although the presence of numerous elevations of the ONM lying in close proximity to free segments of RER was considered indicative of recent dissolution of contact. These data demonstrate modifications in the arrangement of organelles involved in protein synthesis during a period in which the patterns of synthesis by the granule cells are changing but which do not persist through the full period of seizure-induced alterations in synthetic activity.
Pico
R M
RM
Department of Anatomy and Neurobiology, University of California, Irvine 92717.
Gall
C
C
D000818:Animals; D004721:Endoplasmic Reticulum / Q000648:ultrastructure*; D006624:Hippocampus / Q000378:metabolism / Q000648:ultrastructure*; D008854:Microscopy, Electron; D009419:Nerve Tissue Proteins / Q000096:biosynthesis*; D009473:Neuronal Plasticity; D009474:Neurons / Q000378:metabolism / Q000648:ultrastructure*; D009685:Nuclear Envelope / Q000648:ultrastructure*; D051381:Rats; D012016:Reference Values; D012640:Seizures / Q000378:metabolism / Q000473:pathology*
D009419:Nerve Tissue Proteins