Abstract
One hour after long-term potentiation (LTP) in the intact hippocampus, a selective increase in protein F1 in vitro phosphorylation was observed in homogenate prepared from dorsal hippocampus. Protein F1 phosphorylation was directly related to the magnitude and persistence of potentiation. No other phosphoprotein studied exhibited a relationship with synaptic enhancement. Low-frequency, non-potentiating stimulation did not increase protein F1 phosphorylation, and phosphorylation of F1 was not elevated when high-frequency stimulation did not produce potentiation. We also confirmed our earlier demonstration of a similar pattern of results 5 min after LTP. In related work we have previously observed: (1) that protein F1 is a substrate for protein kinase C (PKC); (2) that membrane PKC activity was increased by translocation from the cytosol following LTP; and (3) that membrane PKC activity was directly related to the persistence of enhancement. We therefore predicted in the present study that protein F1 phosphorylation in a dorsal hippocampal membrane fraction would be related to LTP. Hippocampal membrane protein F1 was found to be directly related to both the magnitude and persistence of response enhancement. Thus the molecular events leading to prolonged potentiation may involve increased PKC/protein F1 association. Persistence of potentiation may be related to synaptic growth processes involving the growth-associated function of protein F1.
Original language | English (US) |
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Pages (from-to) | 205-211 |
Number of pages | 7 |
Journal | Brain research |
Volume | 399 |
Issue number | 2 |
DOIs | |
State | Published - Dec 10 1986 |
Funding
We thank Drs. Shew Y. Chan and Kentaro Mura-kami for their helpful discussion of the manuscript, Peter Naumann for programming expertise, David Lilly for assistance with the electrophysiology and Laura Maurer for photographic assistance. This work was supported by MH25281 and AFSOR85-0335. R.B.N. was a National Institute of Drug Abuse predoctoral fellow (Grant DA 05254).
Keywords
- Dentate gyrus
- Intact hippocampus
- Long-term potentiation
- Perforant path
- Protein F
- Protein kinase C
- Protein phosphorylation
- Synaptic plasticity
ASJC Scopus subject areas
- General Neuroscience
- Molecular Biology
- Clinical Neurology
- Developmental Biology