Table 1.

Effect of increasing concentrations of NMDA on spontaneous and sound-driven activity

	256 Hz		512 Hz		1024 Hz
	Spontaneous	Driven	Spontaneous	Driven	Spontaneous	Driven
aCSF	6.6 ± 1.9	46.2 ± 28.1	6.8 ± 0.3	48.4 ± 22.6	7.3 ± 0.9	49.9 ± 39.6
30 μm NMDA	7.5 ± 4.1	62.4 ± 36.3	7.8 ± 3.5	93.7 ± 48.5	10.1 ± 3.0	82.6 ± 69.5
aCSF	8.7 ± 5.7	66.1 ± 43.4	8.1 ± 2.5	65.0 ± 32.6	8.9 ± 1.9	66.7 ± 59.9
100 μm NMDA	14.6 ± 7.0	92.4 ± 49.0	12.3 ± 1.9	118.4 ± 57.5	15.6 ± 2.9	125.2 ± 94.9
aCSF	10.3 ± 4.9	68.2 ± 35.4	6.8 ± 2.2	72.8 ± 41.5	11.1 ± 3.3	81.2 ± 77.7
300 μm NMDA	23.0 ± 12.0	135.4 ± 76.9	16.7 ± 3.3	159.8 ± 76.1	21.8 ± 8.0	131.6 ± 96.3
aCSF	18.5 ± 16.5	94.2 ± 54.7	9.5 ± 2.0	113.0 ± 66.2	13.7 ± 2.2	106.8 ± 97.0

	2048 Hz		4096 Hz
	Spontaneous	Driven	Spontaneous	Driven
aCSF	7.8 ± 3.4	63.6 ± 35.1	6.7 ± 4.1	55.9 ± 20.5
30 μm NMDA	12.1 ± 6.6	86.1 ± 46.9	9.1 ± 6.8	68.9 ± 30.7
aCSF	12.9 ± 6.6	85.0 ± 47.4	13.7 ± 12.8	69.8 ± 26.5
100 μm NMDA	18.8 ± 10.3	142.6 ± 91.9	16.5 ± 10.3	117.5 ± 54.8
aCSF	13.0 ± 8.8	100.5 ± 44.9	10.6 ± 6.7	79.7 ± 22.7
300 μm NMDA	25.5 ± 16.2	157.8 ± 106.8	19.6 ± 10.7	136.9 ± 72.7
aCSF	17.3 ± 10.8	110.7 ± 44.7	13.4 ± 7.6	105.8 ± 46.9

Shown are spontaneous and sound-driven firing rates for each frequency in ICc during perfusion of increasing concentrations of NMDA or washout with aCSF. The sequence in each column follows the order in Figure 4b. The values are shown as mean ± SEM of the multiunit firing rate (spikes/s) during each stimulus presentation averaged across animals (n = 3).