Persistent LTP without triggered protein synthesis.

• Protein synthesis is believed to be involved in stabilizing synaptic plasticity. Effects lasting longer than about 2-3h are considered to require synthesis of new proteins, implying a functional separation between early (E) and late (L) components. However, the issue of constitutive vs. new protein synthesis is still unclear, especially in young animals. Here, we examined the effects of two protein synthesis inhibitors, anisomycin and emetine, on long-term-potentiation (LTP) in CA1 area of hippocampal slices from 12- to 20-day-old rats. Either drug was applied from -30 min to +30 min with respect to LTP induction, a time window previously reported to be critical. However, the LTP remained stable under the entire recording period of 4h (anisomycin), or 8h (emetine). Proper preparation of emetine solution was evidenced by the fact that, in separate experiments, prolonged treatment with emetine gradually blocked baseline responses. Although no corresponding effect was observed with anisomycin, the drug was judged to be potent by its ability to inhibit yeast growth. The ability of anisomycin to inhibit protein synthesis was further confirmed by radiolabeling experiments assessing the degree of leucine incorporation. Our data suggest that LTP up to at least 8h is not dependent on triggered protein synthesis but can be attained by utilizing proteins already available at induction time.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Fysiologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Physiology (hsv//eng)

Nyckelord

Animals

Anisomycin

pharmacology

Drug Administration Schedule

Emetine

pharmacology

Hippocampus

drug effects

metabolism

Leucine

metabolism

Long-Term Potentiation

drug effects

physiology

Memory

drug effects

physiology

Nerve Tissue Proteins

antagonists & inhibitors

biosynthesis

Neurons

drug effects

metabolism

Organ Culture Techniques

Protein Synthesis Inhibitors

pharmacology

Rats

Synapses

drug effects

metabolism

Time Factors

Publikations- och innehållstyp

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