Proestrus : the female attracts males , has a bloody vaginal discharge and her vulva is swollen . proestrus lasts approximately nine days ; the female , however , will not allow coitus at this time 发情前期：母犬开始引诱公犬， * *有血渗出，阴户涨大。发情前期约持续九天，不过，这段时间，母犬并不与公犬交配。
2.
Amy da release of proestrus female rats was apparently higher than estrus , metestrus and ciestrus female rats , but no significant difference was observed among estrus , metestrus and ciestrus female rats . da release in ovx rats was higher compared with male rats , but lower than proestrus female rats . no difference appeared among ovx rats and estrus , moiestrus , ciestrus female rats 电刺激vta诱发的雄鼠amyda释放量明显低于雌鼠和ovx鼠；处于动情前期雌鼠的amyda释放量高于动情期、动情后期和动中文摘要情间期雌鼠；而动情期、后期及间期雌鼠间da释放量差异无统计学意义； ovx鼠da释放量高于雄鼠，低于动倩前期雌鼠，但与动情期、后期及间期雌鼠比较无显著差异。
