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 1mg/kg almost finished the number of writhes (P < 0.01).