TABLE 1.

Plastic changes in ICc and Al after p-cond with or without drugs

	Amount of Changes at 60 min After p-cond
Groups	Recording Site	Response Increase at MT + 10 dB, %	BW Increase at MT + 10 dB, kHz	Threshold Decrease at BF, dB	Background Discharge Increase, %	BF shift at CSu + 5 kHz
1. P-cond with saline	ICc	45.8 ± 6.8 (34)†	2.0 ± 0.1†	5.1 ± 0.3†	20 ± 2.9*	−1.0 ± 0.1 (8/12)*
	Al	56.7 ± 3.4 (23)**	3.8 ± 0.4**	6.1 ± 0.8	14 ± 4.1	−1.0 ± 0.1 (5/10)*
2. P-cond with Atr to ICc	ICc	38.0 ± 9.5 (19)§	1.7 ± 0.1‡	0.0 ± 0.5	12 ± 2.6	0 (19/19)
Atr to Al	Al	48.6 ± 5.1 (12)‡	3.2 ± 0.3	5.4 ± 0.7	10 ± 9.6	0 (14/14)
3. P-cond with Mus to Al	ICc	36.3 ± 4.0 (17)§	1.9 ± 0.2	5.2 ± 0.5*	21 ± 2.8	0 (17/17)
4. p-cond with Mus to Sl	ICc	42.3 ± 5.7 (15)	2.1 ± 0.1‡	5.0 ± 0.5*	13 ± 3.3	0 (15/15)
	Al	58.2 ± 4.6 (16)**	3.7 ± 0.2	5.0 ± 1.0	16 ± 9.8	0 (16/16)
5. Groups 1+4	ICc	44.7 ± 6.4 (49)	2.1 ± 0.1	5.1 ± 0.3	17 ± 3.0
	Al	57.3 ± 3.8 (39)**	3.8 ± 0.3**	5.6 ± 0.6	15 ± 6.1

Values are means ± SE (n).

^*P < 0.05,

^†P < 0.01, t-test; the effects of p-cond are compared with pre-p-cond, i.e., control.

^‡P < 0.05,

^§P < 0.01, t-test; the drug effects are compared with p-cond with saline.

^**P < 0.01, t-test; the effects of p-cond are compared between ICc and Al. ICc, central nucleus of the inferior colliculos; AI, primary auditory cortex; p-cond, pseudo-conditioning; MT, minimum threshold; BF, best frequency; CSu, unpaired conditioning tonal stimulus; Atr, atropine; Mus, Muscimol; SI, Somatosensory Cortex. The AI data were obtained by Ji and Suga (2008).