Roles of the pineal gland and eyes on the formation of photoperiodic rhythms in the activity and biological functions of the chicken and the quail.

本实验旨在研究在恒定黑暗条件下，噪声对雏鸡褪黑激素节律的调节作用。在连续白噪声条件下，松果体和血浆中的塞拉汀浓度均未形成日节律，在实验期间出现峰值。在12小时白噪声和12小时公鸡鸣叫条件下，松果体中的色拉汀浓度呈现明显的日变化，峰值出现在噪声开启的中期和关闭的侧面。分别进行了分析。鸡把白噪声识别为主观夜晚，将公鸡叫声识别为主观白天，说明鸡与鸡之间的交流不利于形成节律，在鸡体内持续黑暗的情况下，噪声可能是形成褪黑激素昼夜节律的调整器。下一步实验旨在阐明松果体摘除和/或盲法对未成熟雏鸡血浆补体激素节律的影响。正常鸡和假松果体鸡的血浆褪黑素浓度均呈现明显的日节律，在SID-SCOTOPH期达到峰值。无论是松果体摘除鸡还是盲鸡(通过双侧眼眶完全摘除)，血浆褪黑素浓度与正常鸡和假手术鸡相比均呈日节律变化，波动较小。但在松果体摘除和失明的鸡中，都没有检测到血浆褪黑素节律。这些结果表明，雏鸡血浆褪黑激素的节律主要受松果体和视网膜的褪黑激素分泌控制，且主要受松果体的分泌控制，而不受增龄雏鸡眼的分泌控制。此外，当刚孵化的雏鸟被松果体切除时。眼球代替松果体主要诱导血浆中的色拉汀节律。

This experiment was undertaken to examine the potentiality of noise as a Zeitgeber on melatonin rhythm of the immature chicken under constant darkness. Under a continuous white noise condition, both selatonin concentrations in the pineal gland and the plasma did not form daily rhythms with a peak during the experimental period. Under a 12hr white noise condition and a 12hr cockerel's calling, selatonin concentrations in the pineal gland showed clear daily rhtyhes with peaks at mid-noise-on time and sid-noise-off time. respectively. Chickens recognized the condition with a white noise as a subjective night, and the condition with a cockerel's calling as a subjective daytime, suggesting communications among chickens are iill>ortant for forming a rhythm, and noise may act as a Zeitgeber for forming circadian rhythms of melatonin under constant darkness in the chicken. Next experiment was conducted to elucidate the effects of pinealectogy and/or blind on plasma selatonin rhythms of immature, -chickens. The plasma melatonin concentrations of intact and sham-pinealectonized chickens showed a prominent daily rhythm with a peak at sid-scotophase. In either pinealectonized or blinded(by complete bilateral orbital enucleation)chickens, plasma melatonin concentrations showed daily rhythms with a small fluctuation compared with a intact and sham-operated chickens. But in both pinealectonized and blinded chickens, no plasma melatonin rhythm detected. These results indicated that the plasma melatonin rhythm is controlled by the melatonin secretion from both pineal and retina in young chicks, and that the rhythm is mainly controlled by the secretion fros pineal but not by that from eyes with advancing age. Furthermore, when the chick just after hatching was pinealectonized. eyes in place of the pineal gland mainly induced to selatonin rhythm in the plasma.