Polyribosomes redistribute from dendritic shafts into spines with enlarged synapses during LTP in developing rat hippocampal slices.
The presence of polyribosomes in dendritic spines suggests a potential involvement of local protein synthesis in the modification of synapses. Dendritic spine and synapse ultrastructure were compared after low-frequency control or tetanic stimulation in hippocampal slices from postnatal day (P)15 rats. The percentage of spines containing polyribosomes increased from 12% +/- 4% after control stimulation to 39% +/- 4% after tetanic stimulation, with a commensurate loss of polyribosomes from dendritic shafts at 2 hr posttetanus. Postsynaptic densities on spines containing polyribosomes were larger after tetanic stimulation. Local protein synthesis might therefore serve to stabilize stimulation-induced growth of the postsynaptic density. Furthermore, coincident polyribosomes and synapse enlargement might indicate spines that are expressing long-term potentiation induced by tetanic stimulation.
Ostroff
Linnaea E
LE
Biology Department, Program in Neuroscience, Boston University, 5 Cummington Street, Boston, MA 02215, USA.
Fiala
John C
JC
Allwardt
Brenda
B
Harris
Kristen M
KM
D000818:Animals; D002451:Cell Compartmentation / Q000502:physiology; D002454:Cell Differentiation / Q000502:physiology*; D048429:Cell Size / Q000502:physiology; D003712:Dendrites / Q000378:metabolism* / Q000648:ultrastructure; D004558:Electric Stimulation; D006624:Hippocampus / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure; D017774:Long-Term Potentiation / Q000502:physiology; D008297:Male; D008854:Microscopy, Electron; D009419:Nerve Tissue Proteins / Q000096:biosynthesis; D009924:Organ Culture Techniques; D011132:Polyribosomes / Q000378:metabolism* / Q000648:ultrastructure; D017729:Presynaptic Terminals / Q000378:metabolism / Q000648:ultrastructure; D021381:Protein Transport / Q000502:physiology*; D012313:RNA / Q000378:metabolism; D051381:Rats; D020318:Rats, Long-Evans; D013569:Synapses / Q000378:metabolism* / Q000648:ultrastructure; D009435:Synaptic Transmission / Q000502:physiology
D009419:Nerve Tissue Proteins; D012313:RNA