Abstract:
:The corticosterone response to the sight of a natural predator was investigated in free-living and captive great tits (Parus major). Free-living great tits responded to the sight of a stuffed, slowly moving Tengmalm's owl, a major predator of great tits, with warning calls and a change in behaviour around a feeder. Great tits returned to the feeder within a few minutes and began to approach the owl, and there was no increase in plasma corticosterone levels in birds sampled 30-50 min after they first saw the owl. Captive great tits in an aviary were exposed for 30 min to a stuffed Tengmalm's owl, to a stuffed brambling, and to a cardboard box. All three stimulus objects were slowly rotated during the exposure period. Great tits exposed to the owl changed their behaviour immediately, and spent most of the time when the owl was visible flying around the aviary and hanging from the roof, with very few visits to a feeder. Great tits exposed to the brambling and to the moving box also changed their behaviour and made fewer visits to the feeder. The great tits responded to the sight of the owl with a marked increase in plasma corticosterone levels, whereas there was no change in corticosterone levels (mean levels < 11 ng/ml) in birds exposed to the brambling or to the moving box. Mean corticosterone levels were high (37.1 +/- 4.9 ng/ml) 0.5 h after exposure to the owl, remained high (38.9 +/- 6.0 ng/ml) 1 h after exposure, and had returned to basal (5.3 plus minus 1.3 ng/ml) 3 h after exposure to the owl. This is the first demonstration for any bird of a complete corticosterone response to a predator. The sight of a predator initiated a corticosterone response in great tits that could not move more than 3 m away, whereas free-living great tits that could choose how far to fly away from the predator either did not initiate a corticosterone response, or had a small corticosterone response in which corticosterone levels were not significantly different from basal 30-50 min later. The results indicate that the initiation of a corticosterone response in birds depends on whether or not a bird perceives that a stimulus is a threat. Furthermore, they illustrate the importance of not making generalised conclusions based on laboratory experiments.
journal_name
Gen Comp Endocrinoljournal_title
General and comparative endocrinologyauthors
Cockrem JF,Silverin Bdoi
10.1006/gcen.2001.7749keywords:
subject
Has Abstractpub_date
2002-02-01 00:00:00pages
248-55issue
2eissn
0016-6480issn
1095-6840pii
S0016648001977494journal_volume
125pub_type
杂志文章abstract::The neuroendocrine light green cells (LGCs), 4 clusters of together approximately 150 giant neurons in the cerebral ganglia of the freshwater gastropod, Lymnaea stagnalis, have been suggested to be involved in the control of growth. The present study examines in greater detail this role and possible actions on energy ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(92)90068-u
更新日期:1992-06-01 00:00:00
abstract::Ghrelin, and nesfatin-1 (encoded by nucleobindin2/nucb2) are two metabolic peptides with multiple biological effects in vertebrates. While sex steroids are known to regulate endogenous ghrelin and NUCB2 in mammals, such actions by steroids in fish remain unknown. This study aimed to determine whether estradiol (E2) an...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2016.01.006
更新日期:2016-03-01 00:00:00
abstract::The purpose of the present study was to determine if central administration of somatostatin influences feeding behavior in layer chicks. Five- to 7-day-old chicks that received intracerebroventricular (ICV) injections of 0.5 or 2 nmol somatostatin increased their food intake at 30 and 60 min after the injection, sugge...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2009.01.022
更新日期:2009-05-01 00:00:00
abstract::The effects of a long term partial food restriction were studied in chickens and rats. In chickens the treatment resulted in increased plasma T4 levels while T4 levels in rats remained unchanged. Plasma T3 decreased in both species. In vitro hepatic outer ring deiodinating type I (ORD-I) activity was not influenced by...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1995.1164
更新日期:1995-12-01 00:00:00
abstract::Homogenates of maturing rainbow trout testes show specific binding sites for 125J-labeled hCG (= 125I-labeled hCG). The binding is competitively inhibited by unlabeled hCG and by a hypophyseal extract of rainbow trout. It could be demonstrated that the tissue 125J-hCG binding specificity is restricted to the gonadal p...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(83)90143-0
更新日期:1983-02-01 00:00:00
abstract::The aim of this study was to identify the major C21 steroids produced in vivo during artificially induced final oocyte maturation and spawning in female common dentex (Dentex dentex). During the spawning season, mature females were treated with a gonadotropin-releasing hormone agonist (GnRHa)-loaded delivery system, w...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.2000.7519
更新日期:2001-07-01 00:00:00
abstract::In the hypothalamus, endocannabinoids affect neuroendocrine activity by means of Gonadotropin-Releasing-Hormone-I (GnRH-I) inhibition. Since most vertebrates, human included, possess at least two GnRH molecular forms, the aim of this work was to investigate the effect of endocannabinoids on GnRH molecular forms other ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2011.07.001
更新日期:2011-09-15 00:00:00
abstract::Many marine invertebrate larvae undergo a dramatic morphological and physiological transition from a planktonic larva to a benthic juvenile. The mechanisms of this metamorphosis in bivalves are mainly unknown. The recent identification in bivalves of a thyroid hormone receptor (TR) gene raises the possibility that as ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2019.113347
更新日期:2020-02-01 00:00:00
abstract::The four-spine sculpin Cottus kazika is a euryhaline teleost, in which faster growth in seawater (SW) and freshwater (FW) has been reported. In this study, cDNA clones encoding growth hormone (GH) and insulin-like growth factor I (IGF-I) were isolated from this species to examine the involvement of the GH/IGF-I axis i...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/s0016-6480(02)00650-0
更新日期:2003-03-01 00:00:00
abstract::Big dynorphin (prodynorphin 209-240), dynorphin A (prodynorphin 209-225), dynorphin B (prodynorphin 228-240), beta-endorphin (beta-lipotrophin 61-90), or Met-enkephalin, each infused into the third ventricle, were tested for their effect on PRL release in the anesthetized turkey hen. Laying hens that received big dyno...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1993.1121
更新日期:1993-08-01 00:00:00
abstract::Leach's storm-petrels accumulate large amounts of body mass throughout the nestling period. Approximately 4days before fledging, nestlings weigh 50-100% more than adults. In order to shed this excess mass, nestlings engage in behavioral anorexia, and leave the burrow when they are light enough to fly. During this pref...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2010.07.019
更新日期:2010-10-01 00:00:00
abstract::Red deer stags have a seasonal pattern of growth, alternating between periods of summer weight gain and winter weight loss that are influenced by photoperiod and by exogenous melatonin. A seasonal pattern of plasma insulin-like growth factor 1, also influenced by photoperiod, underlies the seasonal growth pattern. The...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(92)90156-e
更新日期:1992-07-01 00:00:00
abstract::Neurotransmitters and neurohormones are agents that control gonad maturation in decapod crustaceans. Of these, serotonin (5-HT) and dopamine (DA) are neurotransmitters with known antagonist roles in female reproduction, whilst gonadotropin-releasing hormones (GnRHs) and corazonin (Crz) are neurohormones that exercise ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2013.06.028
更新日期:2013-11-01 00:00:00
abstract::In seasonally breeding, photoperiodic birds, the development of photorefractoriness is associated with decreased brain expression of gonadotropin-releasing hormone-like immunoreactivity (GnRH-li ir) and increased expression of vasoactive intestinal polypeptide-like immunoreactivity (VIP-li ir). Dissipation of photoref...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1999.7361
更新日期:2000-01-01 00:00:00
abstract::Cytochrome P450 17A1 (P450c17) is the key enzyme required for the production of androgenic sex steroids by converting progestogens to androgens. 5α-reductases are enzymes that convert testosterone (T) to dihydrotestosterone (DHT), which has a greater affinity for androgen receptors (AR) and stronger action than T. Our...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2017.09.015
更新日期:2017-12-01 00:00:00
abstract::Recently, we reported the cloning of a cDNA fragment from Fundulus heteroclitus liver encoding the open reading frame of type 2 deiodinase (FhD2). We here report the cloning of 14 kb of genomic sequence from F. heteroclitus that includes the previously reported coding region of the F. heteroclitus Dio2 gene (FhDio2), ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/s0016-6480(02)00071-0
更新日期:2002-09-01 00:00:00
abstract::The skeletal muscles of ectothermic vertebrates possess an elevated glyconeogenic capacity that is responsible for a major portion of lactate removal and glycogen resynthesis following exercise. In lizards, changes in plasma hormone levels and the influence of differing hormone levels on muscle metabolism postexercise...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1996.6866
更新日期:1997-05-01 00:00:00
abstract::Immunocytochemical distribution and dynamics of vasotocin (VT) were studied in the air-breathing catfish Heteropneustes fossilis in relation to the reproductive cycle. Vasotocin was localized in the brain and ovary by streptavidin-biotin immunocytochemistry. The immunoreactivity was found throughout the hypothalamo-hy...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2008.09.003
更新日期:2008-11-01 00:00:00
abstract::The administration of arginine vasotocin (AVT) to gravid snapping turtles with steroidogenically active corpora lutea and high plasma progesterone concentration (1480 +/- 155 pg/ml) did not trigger oviposition, whereas 12 days after ovulation when luteolysis occurred and plasma progesterone concentration was low (570 ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(88)90052-4
更新日期:1988-01-01 00:00:00
abstract::Factors potentially regulating hepatic growth hormone (GH) receptors in coho salmon (Oncorhynchus kisutch) have been investigated. From December to June of the first year, relative changes in hepatic 125I-sGH binding and 35SO4 incorporation by ceratobranchial cartilage were similar. Stunted salmon, which in seawater h...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(92)90256-j
更新日期:1992-11-01 00:00:00
abstract::Components of the renin angiotensin system have been identified in many nonmammalian vertebrates. However, in many of these animals, including reptiles, the physiological functions and importance of the system remain unclear. To aid in the study of the system in a reptile we modified a commercially available radioimmu...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(88)90120-7
更新日期:1988-06-01 00:00:00
abstract::We demonstrated the presence of specific binding sites for bullfrog luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in a testicular crude plasma membrane fraction of the bullfrog, Rana catesbeiana. The equilibrium analysis of the binding showed that a straight line was fitted to the Scatchard plot of L...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(86)90207-8
更新日期:1986-02-01 00:00:00
abstract::Arginine vasotocin (AVT) and isotocin (IT) are fish nonapeptides synthesized in separate hypothalamic neurons from where they are transported to the neurohypophysis for storage and release into circulation. AVT is known to modulate aggression, courtship and parental care or social communication in many species, includ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2011.11.022
更新日期:2012-01-15 00:00:00
abstract::The dynamics of androgen production by perfused Xenopus testis explants has been investigated under various gonadotropic stimulations. Androgens were measured in perfusate by radioimmunoassay. The behavior of hormones in the perfusion system was assessed. Pieces of testis were capable of producing androgens after more...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(83)90057-6
更新日期:1983-09-01 00:00:00
abstract::Renal actions of arginine vasotocin (AVT) and atrial natriuretic peptide (ANP) in teleosts are poorly defined. Administration of these hormones changes renal function, largely explained by systemic vascular effects. The present experiments examine the potential direct action of these hormones on the teleost nephron. T...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1993.1046
更新日期:1993-03-01 00:00:00
abstract::The binding of 125I-labeled ovine prolactin (oPRL) to membrane preparations of several tissues from the male green frog, Rana esculenta, collected during the year is reported. PRL binding to kidney fractions was generally high (range 5-45%). A maximum was observed in the month of October, whereas the lowest value was ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(87)90053-0
更新日期:1987-10-01 00:00:00
abstract::The complete amino acid sequences of alpha subunits of chum salmon (Oncorhynchus keta) gonadotropins (GTHs), GTH I and GTH II, were determined. Subunits were separated by reversed-phase high-performance liquid chromatography. Two alpha subunits, I alpha 1 and I alpha 2, were obtained from GTH I, whereas only one alpha...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(90)90047-p
更新日期:1990-04-01 00:00:00
abstract::A significant reduction in stress-induced plasma cortisol levels is apparent in mature male rainbow trout compared to immature fish of both sexes and of the same age and strain. Mean plasma cortisol levels in groups of immature fish subjected to a standard 1-hr confinement stress were consistently higher (range 93.9 +...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1995.1073
更新日期:1995-06-01 00:00:00
abstract::Seasonally spawning fish rely on a dynamic and complex hormonal interplay to regulate cycles of gonadal development and the regression. Thyroid hormones have been shown to be a key player during gonadal development, and can regulate the activity of a number of essential reproductive hormones. Apoptosis is a vital cell...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2019.113382
更新日期:2020-04-01 00:00:00
abstract::The gonadotropins (GTHs) follicle-stimulating hormone (FSH) and luteinizing hormone (LH) are the key regulators of reproduction. We determined the competence of heterologous recombinant GTHs at eliciting steroid secretion from carp ovaries at different reproductive stages. We collected carp ovaries at: early, mid and ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2012.04.002
更新日期:2012-08-01 00:00:00