Editing Silent synapse (section)

{{Short description|Glutametergic neuronal junction that is typically inactive}}
In [[neuroscience]], a '''silent synapse''' is an excitatory [[glutamate]]rgic [[synapse]] whose postsynaptic [[cell membrane|membrane]] contains [[NMDA receptor|NMDA-type glutamate receptors]] but no [[AMPA receptor|AMPA-type glutamate receptors]].<ref name="Purves 2007">{{cite book | title = Neuroscience, Fourth Edition | last1 = Purves | first1 = Dale | year = 2007 | publisher = Sinauer Associates | pages = 193–5}}</ref> These synapses are named "silent" because normal AMPA receptor-mediated signaling is not present, rendering the synapse inactive under typical conditions. Silent synapses are typically considered to be immature glutamatergic synapses. As the brain matures, the relative number of silent synapses decreases. However, recent research on [[hippocampus|hippocampal]] silent synapses shows that while they may indeed be a developmental landmark in the formation of a synapse, that synapses can be "silenced" by activity, even once they have acquired AMPA receptors. Thus, silence may be a state that synapses can visit many times during their lifetimes.