Article Figures & Data
Figures
- Figure 1.
Blockade of AMPA receptors switches functional synapses into silent ones. An example of functional synapse with NMDA receptor-mediated EPSCs at +60 mV and AMPA receptor-mediated EPSCs at −70 mV. Insets a and b are records at points a and b, respectively. c, d, Application of NBQX specifically blocks the EPSCs at −70 mV (c) and leaves EPSCs at +60 mV (d) intact, indicating that silent synapses result from a loss of AMPA receptor function. The dashed lines denote noise level determined by two times the noise SD here and in all figures.
- Figure 2.
Long-term deprivation converts functional synapses into silent ones. A, C, Examples of functional synapses in barrelette cells of normal PrV in the first and second postnatal week separately. Note that minimal stimulation of TrV induced EPSCs at both +60 and −70 mV with similar failure rate. B, D, The majority of cells in both postnatal weeks showed similar failure rates at different holding potentials. E, G, Examples of silent synapses in both postnatal weeks. Note that minimal stimulation failed to induce EPSCs at −70 mV. F, H, Most of the cells in the deprived PrV exhibited higher failure rates at −70 mV than those at +60 mV.
- Figure 3.
Functional AMPA receptors depended on high-frequency afferents and/or enhanced AMPA receptor exocytosis. A, B, Pairing depolarization (−10 mV) and 50 Hz of 300 stimuli immediately converted silent synapses into functional ones. The thick line in B represents averaged values. C, D, One Hertz of 100 or 300 stimuli had no effect. E, F, Application of glycine (200 μm) resumed AMPA receptor-mediated responses at −70 mV.
