Table 2. Effect of dopamine receptor antagonists on the increase in locomotor activity induced by 7α-hydroxypregnenolone.
Treatment | Locomotor activity, line crossings per 30 min |
---|---|
Vehicle | 25.9 ± 4.1 |
7α-Hydroxypregnenolone | 55.6 ± 6.2* |
7α-Hydroxypregnenolone + haloperidol | 20.8 ± 2.2† |
7α-Hydroxypregnenolone + sulpiride | 25.0 ± 4.5† |
7α-Hydroxypregnenolone + SCH23390 | 51.3 ± 11.8* |
Newts (n = 7 per each treatment) in the nonbreeding period (November and December) were used. The dopamine D1-like receptor antagonist, SCH23390 (1 μg, n = 7), or dopamine D2-like receptor antagonist, haloperidol (1 μg, n = 7) or sulpiride (1 μg, n = 7) was injected i.p. 60 min prior to an i.c.v. injection of 7α-hydroxypregnenolone (1 ng). Results were expressed as the mean ± SEM total number of crossings. *, P < 0.01 vs. vehicle. †, P < 0.01 vs. 1 ng of 7α-hydroxypregnenolone alone by one-way ANOVA, followed by Duncan's multiple range test.