Table 1.

Electrophysiological responses

Line	Baseline voltage, V	Baseline spike response, mV	Tetanus voltage, V
WT	4.0  ± 0.23	1.05  ± 0.2	6.0  ± 0.25
G-NonP	3.9  ± 0.56	1.31  ± 0.6	5.8  ± 0.15
G-Phos	3.6  ± 0.53	1.20  ± 0.7	5.5  ± 0.42
G-Perm	4.0  ± 0.21	1.15  ± 0.3	6.0  ± 0.19

Electrophysiological responses to the perforant path stimulus prior to LTP were not different among the three transgenic mouse lines (G-Phos, G-NonP, and G-Perm), nor was there a difference between transgenic mice and nontransgenic (WT) controls. Among the four groups, there were thus no differences in: (i) baseline voltage, the voltage level used to stimulate perforant path and elicit the criterion baseline response, a population spike having one-third the amplitude of the population EPSP; (ii) baseline spike response, population spike amplitude prior to LTP; and (iii) tetanus voltage, the minimum stimulation level required to elicit the maximum population spike. The data represent mean values ± SEM.