Table 3.

Comparison of results obtained with and without BAPTA in the recording electrode in experiments in which the holding potential was returned to −70 mV

	Without BAPTA			With BAPTA
	Total	Neonate	Adult	Total	Neonate	Adult
Number of cells	39	21	18	49	28	21
Number of connections	53	30	23	70	42	28
Number “silent”	6 (11%)	3	3	4 (6%)	2	2
Number of persistentEPSCs on return to −70 mV	6 (100%)	3	3	4 (100%)	2	2

A summary of results obtained in slices from neonates (aged 4–14 d) or adults (aged 6–9 weeks), with or without BAPTA in the recording electrode. Number “silent” shows the number (and percentage) of connections at which EPSCs were observed at a holding potential of +50 mV while stimulating at a level that was initially subthreshold when the cell was held at −70 mV (“silent synapses”). The bottom row gives the number (and percentage) of these “silent synapses” for which AMPAr-mediated EPSCs were seen when the holding potential was returned to −70 mV.