Expression of long-term adaptation of synaptic transmission requires a critical period of protein synthesis
Open Access
- 1 April 1990
- journal article
- research article
- Published by Society for Neuroscience in Journal of Neuroscience
- Vol. 10 (4), 1099-1109
- https://doi.org/10.1523/jneurosci.10-04-01099.1990
Abstract
The crayfish claw closer muscle is innervated by 2 distinct excitatory motoneurons, one tonic and the other phasic. The phasic motoneuron is relatively inactive and generates large EPSPs that normally depress rapidly with repetitive stimulation at moderate frequencies. Stimulation of the phasic motoneuron in vivo for 3 d at 5 Hz (2 hr/d) produced a marked adaptive shift in the neuromuscular synaptic response properties of the motoneuron: average initial EPSPs and depression of EPSPs were significantly reduced. We tested the hypothesis that neuronal protein synthesis is required for full expression of long-term adaptation (LTA). A reversible inhibitor of neuronal protein synthesis, cycloheximide (CHX), was injected into intact crayfish at various times prior to, during, or after each stimulation period. At a dosage of 5 micrograms/gm body weight, CHX inhibited the incorporation of [35S]- methionine into abdominal nerve cord protein for approximately 2 hr after administration (greater than 80% inhibition). Full expression of LTA was selectively blocked when CHX was administered 6 hr or 2 hr prior to each stimulation period. Both the reduction in initial EPSP amplitude and the resistance to synaptic depression were significantly attenuated. CHX administered at the onset of or at the end of each stimulation period did not affect the expression of LTA. Control experiments using unstimulated animals showed that neither chronic nor acute administration of CHX adversely affected the phasic axon's synaptic response properties. Our results suggest that full expression of neuronal LTA requires the presence of a pool of preexisting, short- lived (or rapidly utilized) protein(s). Depletion of such a pool prior to each stimulation period appears to interfere with subsequent induction of LTA.This publication has 27 references indexed in Scilit:
- Effects of altered sensory experience on the responsiveness of the locust descending contralateral movement detector neuronJournal of Comparative Physiology A, 1980
- Disuse enhances synaptic efficacy in spinal mononeurones.The Journal of Physiology, 1979
- Correlation between presynaptic dense bodies and tranmitter output at lobster neuromuscular terminals by serial section electron microscopyBrain Research, 1979
- Cell-to-cell transfer of glial proteins to the squid giant axon: The glia- neuron protein transfer hypothesisThe Journal of cell biology, 1977
- Inhibitory effect of streptomycin and related antibiotics on the glutamate receptor of the crayfish neuromuscular junctionNeuropharmacology, 1977
- A Rapid and Sensitive Method for the Quantitation of Microgram Quantities of Protein Utilizing the Principle of Protein-Dye BindingAnalytical Biochemistry, 1976
- FAST AND SLOW COMPONENTS IN AXONAL TRANSPORT OF PROTEINThe Journal of cell biology, 1968
- Axonal migration of proteins in the central nervous system and peripheral nerves as shown by radioautographyJournal of Comparative Neurology, 1963
- A further study of the statistical composition of the end‐plate potentialThe Journal of Physiology, 1955
- The double motor innervation of the adductor muscle in the claw of the crayfish1The Journal of Physiology, 1936