INTERACTIONS OF CORTICOSTERONE WITH FEEDING, ACTIVITY AND METABOLISM IN PASSERINE BIRDS
INTERACTIONS OF CORTICOSTERONE WITH FEEDING, ACTIVITY AND METABOLISM IN PASSERINE BIRDS
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DOI：
10.2307/3676661
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发表时间：
1992-07-01
期刊：
影响因子：
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通讯作者：
WINGFIELD, JC
中科院分区：
文献类型：
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作者：
ASTHEIMER, LB;BUTTEMER, WA;WINGFIELD, JC
皮质酮（B）可能在营养应激条件下促进摄食行为中发挥直接作用。然而，外源性B和营养应激的影响表明了一个复杂的关系，喂养状态，感知或预期的营养应激，和以前的历史。对笼养白冠带毛雀和麻雀进行了一系列调查。外源性B不影响鸟类的旋律、觅食行为和摄食率。当食物返回时，植入B的鸟在禁食24小时后再进食时间更长，强度更大。此外，B植入的鸟类显示出较低的活动（鲈鱼跳跃）比对照组时，随意喂养，但禁食时，这种趋势与B植入的鸟类显示出增加的活动和明显的逃跑行为。在第二项研究中，在鸟舍中饲养的小群松黄雀和黑眼容科斯Junco hyemalis禁食24小时后，血浆中的B水平高于禁食1小时后再喂食的类似鸟群。然而，最高水平的B在禁食的鸟类仍然低于自由生活的同种暴露于捕获压力。这种低幅度调制的血浆B水平的关系，喂养状态得到证实的结果，从自由生活的松金丝雀和拉普兰长刺Calcarius lapponicus在暴风雪中捕获。尽管在风暴期间异常高的进食强度，只有一些松金丝雀和没有拉普兰长距的个人有升高的循环水平的B。在后一种物种中，系列样本显示在捕获后15分钟内B水平非常高，表明风暴导致肾上腺分泌活动增强。最后，在白冠麻雀中，外源性B通过降低夜间觉醒的频率和幅度，大大降低了夜间代谢消耗。这表明B在觅食不可能的时间内可能具有节能效果，并且可能确保个体将保留足够的资源以在第二天寻找食物。综上所述，我们的数据表明，B可能是重要的启动食物搜索期间的食物剥夺。似乎只需要少量增加B分泌，从而促进食物定位后快速恢复体内平衡。尽管在长期营养应激下，基础B水平仍然较低，但肾上腺分泌B的潜力在进一步应激时显著增加。
Corticosterone (B) may play a direct role in the promotion of feeding behavior under conditions of nutritional stress. However, effects of exogenous B and nutritional stress in passerines indicate a complex relationship of fed state, perceived or anticipated nutritional stress, and previous history. In a series of investigations on caged White-crowned Zonotrichia leucophrys and Song Sparrows Z. melodia, foraging behaviors and feeding rates were unaffected by exogenous B in fed birds. When food was returned, birds implanted with B refed for longer and with greater intensity following the 24 hour fast. Additionally, B-implanted birds showed lower activity (perch hopping) than controls when fed ad libitum, but when fasted this trend reversed with B-implanted birds showing increased activity and apparent escape behavior. In a second study, small flocks of Pine Siskins Carduelis pinus and Dark-eyed Juncos Junco hyemalis held in aviaries and fasted for 24 hours had higher plasma levels of B than similar flocks that had been allowed to refeed for 1 hour after fasting. However, the highest levels of B in fasted birds were still lower than in free-living conspecifics exposed to capture stress. This low amplitude modulation of plasma B levels in relation to fed state was corroborated by results from free-living Pine Siskins and Lapland Longspurs Calcarius lapponicus captured during snow storms. In spite of unusually high feeding intensities during the storm, individuals of only some Pine Siskins and no Lapland Longspurs had elevated circulating levels of B. In the latter species, serial samples revealed very high levels of B within 15 minutes of capture suggesting enhanced adrenal secretory activity as a result of the storm. Finally, in White-crowned Sparrows, exogenous B substantially reduced overnight metabolic expenditure by reducing the frequency and amplitude of arousal bouts during the night. This suggested a possible energy savings effect of B during the hours when foraging was impossible and, possibly, insurance that the individual will retain sufficient resources to seek food the following day. Taken together, our data suggest that B may be important for initiation of food-searching during periods of food deprivation. Only small increases in B secretion appear to be required thus facilitating a rapid return to homeostasis after food is located. Although under prolonged nutritional stress the basal levels of B remained low, adrenal potential to secrete B in response to further stress increased dramatically.