The power of silence

Abstract

Previous studies have shown that blocking neural activity with tetrodotoxin (TTX) leads to an increase in synaptic strength. The authors further examined the effects of TTX treatment on Schaffer collateral–CA1 synapses in cultured hippocampal slices and found that chronic activity blockade leads to the formation of new, silent synapses (lacking AMPA receptors). Furthermore, induction of long-term potentiation activated these silent synapses by inducing AMPA receptor insertion. Thus, neural networks can compensate for the lack of synaptic activity by increasing the synaptic strength of existing synapses and by promoting the emergence of new synapses.