Photoperiodic control of the cloacal gland of the Japanese quail

Changes in photoperiod cause correlated changes in testes, cloacal glands, cloacal foam, and reproductive behavior of male Japanese quail. The cloacal protrusion may serve as a convenient external index of androgen, permitting repeated measurement without operation on or killing of the animal.     

Harderian gland: an extraretinal photoreceptor influencing the pineal gland in neonatal rats?

The circadian rhythm of pineal serotonin and the influence of light on that rhythm have been confirmed. Removal of the Harderian gland abolishes the response to light in blinded animals, which suggests that this gland may act as the extraretinal transducer involved in the persistence of the pineal rhythm in blinded suckling rats.     

Melatonin content of the human pineal gland

Gas chromatography with electron capture detection was used to quantitate melatonin in single human pineal glands. The sensitivity of this melatonin assay is in the low picogram range. A 24-hour rhythm of pineal melatonin content was observed.     

Memory in the Japanese quail: effects of puromycin and acetoxycycloheximide

Intracerebral injections of puromycin produced memory deficits in naive quail trained to discriminate between red and green stimuli. Puromycin aminonucleoside, acetoxycycloheximide, and saline had no such effect. After a single reversal of the visual cues, naive quail treated with puromycin performed better than control birds. Also, puromycin had no effect on performance when injected into previously trained animals. High doses both of puromycin and acetoxycycloheximide inhibited ribonucleic acid and protein synthesis to a similar extent, while low doses of puromycin inhibited only protein synthesis. Since only puromycin inhibited memory, the basis for its effect appears more likely to be mediated by the action of peptidyl-puromycin rather than by the quantitative inhibition of macromolecular synthesis or by some nonspecific toxic action.     

Indole metabolism in the pineal gland: a circadian rhythm in N-acetyltransferase

The activity of N-acetyltransferase in the rat pineal gland is more than 15 times higher at night than during the day. This circadian rhythm persists in complete darkness, or in blinded animals, and is suppressed in constant lighting. The N-acetyltransferase rhythm is 180 degrees out of phase with the serotonin rhythm and is similar to the norepinephrine and melatonin rhythms. Experiments in vitro indicate that norepinephrine, not serotonin, regulates the activity of N-acetyl-transferase through a highly specific receptor.     

Genetic resistance to aflatoxin in Japanese quail

Progress was rapid in attempts to develop lines of quail resistant to acute aflatoxicosis induced by oral dosing with aflatoxin. After five generations of selection, 8- and 11-fold differences were present in mortality between two selected lines and their respective control lines. These quail lines should be of value in investigating the physiological basis of resistance to aflatoxin.     

Biosynthesis of biopterin: adrenergic cyclic adenosine monophosphate-dependent inhibition in the pineal gland

Pineal glands in organ culture synthesize and release biopterin and are able to maintain concentrations of biopterin occurring in vivo for up to 54 hours in vitro. The intracellular biopterin content is reduced 50 percent by treatment with l-norepinephrine or cyclic adenosine monophosphate derivatives, but not by d-norepinephrine. This is an indication that biopterin levels are regulated by an adrenergic cyclic adenosine monophosphate-dependent mechanism. The decline in tissue biopterin content, produced mainly by inhibited of biosynthesis, is maximal at 6 hours and is not associated with either an increase in biopterin release or a shift in the reduction state of the biopterin.     

Harderian gland: influence on pineal hydroxyindole-O-methyltransferase activity in neonatal rats

A circadian rhythm has been found in hydroxyindole-O-methyltransferase activity of the pineal gland of blinded 12-day-old rats. Five additional hours of lighting can partly prevent the nocturnal increase in pineal hydroxyindole-O-methyltransferase activity in such rats. Removal of the Harderian gland abolishes this response to light in 12-day-old blinded animals, giving further support to the suggestion that this gland may function as an extraretinal photosensitive organ influencing the pineal gland in blinded suckling rats.     

Japanese quail can learn phonetic categories

Japanese quail (Coturnix coturnix) learned a category for syllable-initial [d] followed by a dozen different vowels. After learning to categorize syllables consisting of [d], [b], or [g] followed by four different vowels, quail correctly categorized syllables in which the same consonants preceded eight novel vowels. Acoustic analysis of the categorized syllables revealed no single feature or pattern of features that could support generalization, suggesting that the quail adopted a more complex mapping of stimuli into categories. These results challenge theories of speech sound classification that posit uniquely human capacities.     

Rhodopsin kinase activity in the mammalian pineal gland and other tissues

Rhodopsin kinase, an enzyme involved in photochemical transduction in the retina, has been found in the mammalian pineal gland in amounts equal to those in the retina; other tissues had 7 percent of this amount, or less. This finding suggests that, in mammals, rhodopsin kinase functions in the pineal gland and other tissues to phosphorylate rhodopsin-like integral membrane receptors and is thereby involved in signal transduction.     

Genetic control of melatonin synthesis in the pineal gland of the mouse

Pineal melatonin may play an important role in regulation of vertebrate circadian rhythms and in human affective disorders. In some mammals, such as hamsters and sheep, melatonin is involved in photoperiodic time measurement and in control of reproduction. Although wild mice (Mus domesticus) and some wild-derived inbred strains of mice have melatonin in their pineal glands, several inbred strains of laboratory mice (for example, C57BL/6J) were found not to have detectable melatonin in their pineal glands. Genetic analysis suggests that melatonin deficiency in C57BL/6J mice results from mutations in two independently segregating, autosomal recessive genes. Synthesis of melatonin from serotonin in the pineal gland requires the enzymes N-acetyltransferase (NAT) and hydroxyindole-O-methyltransferase (HIOMT). Pineal glands from C57BL/6J mice have neither NAT nor HIOMT activity. These results suggest that the two genes involved in melatonin deficiency are responsible for the absence of normal NAT and HIOMT enzyme activity.     

Tryptophan hydroxylation: measurement in pineal gland, brainstem, and carcinoid tumor

Development of a rapid and sensitive radioassay has permitted study of the conversion of tryptophan to 5-hydroxytryptophan in mammalian tissues. Of normal tissues examined, beef and rat pineal gland contained the highest activity. This is the first direct demonstration of tryptophan hydroxylase in this hydroxyindole-rich tissue. Rat and rabbit brainstem and human carcinoid tumor also had quantities of enzyme that could be measured easily. The reaction requires a reduced pteridine and oxygen and is inhibired by Para-Chorophenylalanine.     

下丘脑GnRH—Ⅰ mRNA在绍兴鸭松果腺中的表达

用反转录多聚酶链式反应 (RT PCR)方法检测 30至 15 0日龄绍兴鸭松果腺内GnRH ImRNA含量的变化。结果表明 ,绍兴鸭松果腺内存在GnRH ImRNA的表达且其核苷酸序列与绍兴鸭下丘脑内GnRH ImRNA仅有一个核苷酸差异 ,且不影响氨基酸的编码序列 ,但 30至 15 0日龄松果腺内GnRH ImRNA含量未出现显著性差异 (P >0 0 5 )。     

下丘脑GnRH-I mRNA在绍兴鸭松果腺中的表达

用反转录多聚酶链式反应(RT-PCR)方法检测30至150日龄绍兴鸭松果腺内GnRH-I mRNA含量的变化.结果表明,绍兴鸭松果腺内存在GnRH-I mRNA的表达且其核苷酸序列与绍兴鸭下丘脑内GnRH-I mRNA仅有一个核苷酸差异,且不影响氨基酸的编码序列,但30至150日龄松果腺内GnRH-I mRNA含量未出现显著性差异(P>0.05).     

Pineal function and oviposition in Japanese quail: superior cervical ganglionectomy and photoperiod

Bilateral ablation of the superior cervical ganglia appears to deprive the pineal body of sympathetic innervation. Although this procedure presumably interrupts the neural circuit for transmission of optic information to the pineal, oviposition rates of ganglionectomized females exposed to stimulatory (15-hour) or to nonstimulatory (4-hour) daily photoperiods do not differ from those of the controls.     

Adenyl cyclase activity in rat pineal gland: effects of chronic denervation and norepinephrine

Adenyl cyclase activity in the pineal gland of rats was determined by measuring the rate of formation of radioactive cyclic 3',5'-adenosine monophosphate from (14)C-labeled adenosine triphosphate. Norepinephrine added in vitro to pineal homogenates enhanced this activity, while denervation of the pineal gland by superior cervical ganglionectomy did not significantly reduce it. The enzyme in these denervated glands was more responsive to the stimulatory effects of norepinephrine.     

Adenosine 3'-5'-monophosphate in rat pineal gland: increase induced by light

Rats were maintained in alternating periods of 12 hours of light and 12 hours of darkness. The concentration of adenosine 3',5'-monophosphate in pineal gland was six times higher at the end of the light period than at the end of the period of darkness. This effect of light was abolished in blinded animals.     

中国黄羽鹌鹑哈德氏腺发育的增龄变化及形态组织学观察

为研究不同周龄中国黄羽鹌鹑哈德氏腺的组织学结构,采集0、1、2、3、4、5、6、10、14、18、22、26、30、34、38周龄健康中国黄羽鹌鹑的哈德氏腺,光学显微镜下观察哈德氏腺的显微组织结构,电镜下观察哈德氏腺的超微结构变化。结果显示,黄羽鹌鹑哈德氏腺位于眼眶内、眼球腹侧和后内侧,出生时就具备完整的形态,在视神经区呈喙状延伸,一端游离,另一端由腺体导管开口于第三眼睑弯窿的内角,腺体呈不规则带状,一端小,一端大,浅粉色,腺体绝对质量、长和宽随周龄逐渐增大。哈德氏腺为复管泡状腺,腺体外有结缔组织被膜,被膜延伸至腺体实质中,将腺体分为多个大小不同的小叶,小叶由腺泡和腺管组成。中国黄羽鹌鹑哈德氏腺在出生后逐渐发育,4周龄时达到成熟,5至38周龄为成熟持续期。     

Enzymatic synthesis of melatonin in avian pineal body: extraretinal response to light

In the chick pineal body, activity of the melatonin-forming enzyme hydroxyindole-O-methyl transferase is greater in the light than in darkness. Neither bilateral enucleation of the eyes nor sympathetic denervation prevented this light-induced elevation of enzyme activity. This fact indicates that in the bird, in contrast to mammals, neither the retinas nor sympathetic innervation of the pineal body are essential for environmental control of melatonin formation.