Table 2.
A. Percent prepulse inhibition (mean ± SEM) at each of five prepulse stimulus intensities (3–18 dB above background) in BN rats and WKY rats. Rats received an IP injection of either saline (SAL) or the 5-HT1A receptor antagonist, WAY, followed 10 min later by an ICV infusion of either SAL or CRF. The results of all analyses are reported in the text. In BN rats, CRF alone significantly reduced PPI. This effect was not altered by administration of WAY. WAY alone had no effect on PPI. In WKY rats neither treatment alone, nor the combination of treatments affected PPI. | |||||
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3 dB PP | 6 dB PP | 12 dB PP | 15dB PP | 18 dB PP | |
BN Rats | |||||
SAL/SAL | 3.8 ± 2.7 | 5.3 ± 3.3 | 18.6 ± 2.6 | 24.9 ± 4.0 | 36.9 ± 3.4 |
SAL/0.3 µg CRF | −2.6 ± 5.6 | −10.2 ± 7.3 | 10.2 ± 5.9 | 13.5 ± 5.8 | 20.5 ± 4.5 |
WAY/SAL | 1.1 ± 3.2 | −0.8 ± 5.6 | 9.1 ± 4.6 | 18.2 ± 5.2 | 29.8 ± 4.0 |
WAY/0.3 µg CRF | −1.0 ± 3.7 | −15.8 ± 7.3 | −2.4 ± 9.9 | 2.4 ± 11.0 | 11.7 ± 6.0 |
WKY Rats | |||||
SAL/SAL | 6.8 ± 5.4 | 18.2 ± 13.5 | 38.0 ± 5.2 | 47.6 ± 5.3 | 56.0 ± 4.9 |
SAL/0.3 µg CRF | 3.2 ± 4.3 | 8.0 ± 7.6 | 38.8 ± 10.3 | 44.7 ± 6.5 | 56.1 ± 5.4 |
WAY/SAL | −5.3 ± 7.1 | −11.0 ± 10.3 | 44.5 ± 5.6 | 46.6 ± 5.4 | 60.4 ± 6.5 |
WAY/0.3 µg CRF | −5.2 ± 13.7 | 2.5 ± 11.8 | 49.2 ± 4.4 | 43.5 ± 9.2 | 61.4 ± 4.6 |
B. Baseline startle amplitude (mean ± SEM) in BN and WKY rats on the trials from which the data used to calculate percent PPI were collected. | |||
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BN Rats | WKY Rats | ||
SAL/SAL | 144.3 ± 20.6 | 120.9 ± 9.9 | |
SAL/0.3 µg CRF | 101.4 ± 9.6 | 124.8 ± 15.9 | |
WAY/SAL | 97.1 ± 9.6 | 75.6 ± 15.5 | ** |
WAY/0.3 µg CRF | 81.7 ± 10.0 | 58.4 ± 11.2 |
C. The effect of CRF and WAY on percent habituation (mean ± SEM) in BN and WKY rats. Neither treatment alone, nor the combination of treatments affected within-session habituation. Percent habituation was calculated as 100-100*(average startle amplitude on the last 6 startle alone trials/average startle amplitude on the first 6 startle alone trials). | ||
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BN Rats | WKY Rats | |
SAL/SAL | 14.1 ± 8.1 | 48.1 ± 9.4 |
SAL/0.3 µg CRF | 29.7 ± 10.9 | 53.0 ± 4.0 |
WAY/SAL | 30.6 ± 11.0 | 60.0 ± 6.5 |
WAY/0.3 µg CRF | 36.9 ± 8.1 | 54.6 ± 6.8 |
Overall ANOVA (see text) revealed that WAY caused a significant reduction in baseline startle amplitude (** p < .001). This effect was not rat strain-dependent, and it did not interact with CRF.