Incubation of eggs is a critical component of parental care in avian species. However, we do not fully understand the neuroendocrine mechanisms underlying this vital behavior. While prolactin is clearly involved, it alone cannot explain the fine-tuning of incubation behavior. The present experiments explored the possibility that incubation is reinforced through a hedonic system in which contact with eggs elicited an opiate-mediated reinforcing state. Blockade of opiate receptors with naloxone reduced time ring neck doves (Streptopelia risoria) spent on the nest, possibly by uncoupling the opiate-receptor mediated hedonic experience of contact with eggs from nest-sitting behavior. Likewise, activation of opiate receptors with morphine also reduced time spent on the nest, possibly by activating an opiate-receptor mediated hedonic experience, hence rendering the eliciting behavior (contact with eggs) unnecessary. Taken together, the results suggest that the opiate system may play a previously unrecognized role in facilitating incubation through reinforcement.

蛋的孵化是鸟类父母照顾的重要组成部分。然而，我们并不完全了解这种重要行为背后的神经内分泌机制。虽然明显涉及催乳素，但它本身并不能解释孵化行为的微调。本实验探讨了通过快感系统加强孵化的可能性，在该系统中，与鸡蛋的接触会引起阿片类药物介导的加强状态。用纳洛酮阻断鸦片受体减少环颈鸽（Streptopelia risoria）的时间) 花在鸟巢上，可能是通过将鸦片受体介导的与蛋接触的享乐体验与坐鸟行为分离。同样，用吗啡激活阿片受体也减少了在巢上花费的时间，这可能是通过激活阿片受体介导的快感体验，从而使引发行为（与鸡蛋接触）变得不必要。总之，结果表明鸦片制剂系统可能在通过强化促进孵化方面发挥了以前未被认识到的作用。