Table 2.

Summary of incidence of “silent synapses” in electrophysiological experiments

	Neonate	Adult	Total
Number of cells	67	59	126
Number of connections	109	77	186
Number of silent synapses	10 (9%)	9 (12%)	19 (10%)

This shows the incidence of connections at which EPSCs were observed at a holding potential of +50 mV while stimulating at a level that was initially subthreshold while the cell was held at −70 mV (“silent synapses”). Results obtained in slices from neonates (4–14 d) or adults (6–9 weeks) are shown separately.