Increased retention of calcium in the dendrites of long-term potentiated CA1 neurons of the hippocampal slice. A combined electrophysiological and electron histochemical study.
In view of the importance of calcium in the induction of long-term potentiation (LTP), experiments were carried out to localize calcium at the electron microscopic level in the CA1 region of guinea pig hippocampal slices, following high-frequency stimulation of the Schaffer collaterals. Apart from the ultrastructural localization, a semi-quantitative method was used to count the calcium-containing deposits in electron micrographs. Significantly more calcium-containing deposits were seen in the dendrites of the stratum radiatum in slices with LTP than in those without it. A moderate increase of the extradendritic deposits was observed, too. The calcium content of the deposits was determined by means of EGTA incubation and X-ray analysis. The presented results, together with the relevant literature data, underline the importance of calcium-activated processes in postsynaptic structures probably involved in the generation of LTP.
Kuhnt
U
U
Max-Planck-Institute for Biophysical Chemistry, Department of Neurobiology, Göttingen, Federal Republic of Germany.
Mihály
A
A
Siklós
L
L
Joó
F
F
D000818:Animals; D002118:Calcium / Q000032:analysis / Q000502:physiology*; D004533:Egtazic Acid; D004558:Electric Stimulation; D004577:Electron Probe Microanalysis; D005260:Female; D006168:Guinea Pigs; D006624:Hippocampus / Q000378:metabolism* / Q000502:physiology / Q000648:ultrastructure; D066298:In Vitro Techniques; D008297:Male; D008854:Microscopy, Electron
D004533:Egtazic Acid; D002118:Calcium