Although single application of coniine in 10 mg/kg did not decrease number of writhes,
it attenuated these writhes significantly after injection with 0.3 mg/kg morphine (coniine: 29 ± 1.21, coniine + morphine: 16.83 ± 1.3; P < 0.05).
At the same dose of coniine, application of morphine in 1 mg/kg almost finished the number of writhes (P < 0.01)