Table 2.

Effect of GFP expression on the kinetics of depression and facilitation of SM pairs

	n	Initial EPSP (mV)	Depression: EPSPs 9–11 (% of initial)	Facilitation: EPSPs 12–14 (% of initial)
GFP	12	4.8  ± 2.8	18  ± 5%	125  ± 24%
Noninjected	6	6.3  ± 1.9	27  ± 3%	94  ± 16%
ttests		NS	NS	NS

At moderately depressed synapses, GFP expression had no effect on synaptic properties. Mean initial postsynaptic potential, depression (EPSPs 9–11), and facilitation (EPSPs 12–14) of sensorimotor synapses were comparable in the GFP-positive and noninjected groups. In this control experiment, 5-HT was applied between EPSPs 11 and 12 (interstimulus interval, 30 sec).