ISSN:0003-276X    

DOI:10.1002/ar.1091580302

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractA major branch of Mauthner's (M‐) axon has been found in larvae ofXenopus laevis(Daudin). After giving off an inhibitory collateral toward the contralateral M‐cell, the branch continues forward to the preoptic nucleus of the forebrain. Following stimulation of the M‐cell, the function of the ascending branch of its axon may be to elicit startle responses corresponding to the defensive hypothalamic responses of higher verteb

ISSN:0003-276X    

DOI:10.1002/ar.1091580303

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractThe contents of the facial canal (first and second parts of the facial nerve, and geniculate ganglion), the tympanic plexus, the greater and lesser petrosal nerves, and all intervening connections were dissected in 40 cadavers. This entire nerve complex was removed in 30 cases, and in parts in ten cases, dehydrated, and stained with Sudan Black B or Protargol. A constant communication from the second part of the facial nerve, the geniculate ganglion, or the greater petrosal nerve was observed to pass to the lesser petrosal nerve in all dissections. A review of the literature indicates other points relative to the exchange of autonomic fibers between the facial and glossopharyngeal nerves.

ISSN:0003-276X    

DOI:10.1002/ar.1091580304

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractA comparison of the histological pattern of the thyroid glands of 138 wild and 157 domesticated Norway rats showed that the domesticated rat has smaller epithelial cells, greater uniformity in the size of follicles, larger follicular lamina, and fewer vacuoles in the intrafollicular colloid. These differences are not present at birth but develop gradually with age. Hypophysectomy causes a loss of these differences and results in an identical histologic pattern of atrophy in the two strains of rats. There is greater uniformity of thyroid I131uptake and labelling of the components of thyroglobulin in the domesticated rat, but the average percent uptake of I131in the thyroid glands of both strains is the same.These differences may be accountable partly on the basis of different reactions to the environment conditioned by different temperaments in the two strains, by actual differences in the environment, and by genetic differences.

ISSN:0003-276X    

DOI:10.1002/ar.1091580305

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractThe rate of daily secretion of thyroid hormone was compared in male mice of five inbred strains, the DBA/2, the C57B1/6, the St/6J, the CBA/J and the Swiss Albino strain.The method employed to measure thyroid secretion rates is based on a procedure which involves the production of goiters by daily propylthiouracil (PTU) administration in the drinking water and determining subsequently the effective dose of the exogenous thyroxin required to inhibit goiter development and maintain normal control weights of thyroid glands.Statistically significant differences were observed in output of thyroid hormone between the different genetic strains tested. The levels of thyroid activity were lowest in the temperamentally most active strains (DBA/2 and CBA/J) while the more placid strains exhibited higher levels of thyroid secretion (Swiss Albino and ST/6J).This unexpected finding is interpreted to indicate that, if there exists any correlation between thyroid hormone and behavior, the more active strains differ from the more placid ones in tissue sensitivity to thyroid hormone rather than in concentration of levels of circulating hormone.

ISSN:0003-276X    

DOI:10.1002/ar.1091580306

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractGroups of nulliparous pregnant rabbits were bilaterally ovariectomized on the third, fifth, sixth or seventh days of gestation; some groups were then treated daily with 40 mg of progesterone alone or with 4 mg progesterone alone or in combination with estradiol at a ratio of 1:400 or 1:4000. Animals ovariectomized 3 dayspost coitum (p.c.)were autopsied four days later; those ovariectomized five, six, or seven daysp.c.were autopsied 24 hours later. The number of viable blastocysts per doe was greatly decreased following ovariectomy; however, the number was increased by treatment with progesterone alone or in combination with estradiol (1:400 or 1:4000). The weight of blastocyst and embryonic matter (trophoblast and embryonic disc), and the volume of blastocoelic fluid in the blastocyst at six or seven daysp.c.were neither affected by ovariectomy nor by injection of 4 mg of progesterone. The weight of the blastocysts was significantly reduced when ovariectomy was performed seven daysp.c. The concentration of the biochemical compounds in the blastocoelic fluid was not altered by ovariectomy at five or seven daysp.c. In contrast, the concentration of glucose, lactic acid, protein N and nonprotein in the blastocyst was greatly lowered by ovariectomy at six daysp.c., being partly alleviated by daily injections of progesterone, alone or in combination with estradiol. Ovariectomy at three daysp.c.was no more detrimental than later ovariectomy if steroids were administrated.

ISSN:0003-276X    

DOI:10.1002/ar.1091580307

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractTwenty‐five mature rabbits were assigned in groups of five to be ejaculated at one of the following frequencies for a period of six weeks: Sexual rest (SR), one ejaculation on Friday (1 × F), four ejaculations on Friday (4 × F), one ejaculation daily Monday through Saturday (1 × M–S), and two ejaculations Monday, Wednesday, and Friday (2 × MWF). Upon slaughter after SR, the average distributions of sperm in the capita‐corpora epididymides, caudae epididymides, and ductus deferentia were 184, 1,028, and 86 × 106, respectively.Ejaculation at each frequency significantly reduced the numbers of sperm found in the caudae epididymides, but neither weights of nor sperm numbers in the capitacorpora epididymides were affected by ejaculation frequency. While 79 ± 3% of extragonadal sperm were found in the caudae epididymides after SR, only 27 ± 5% were found there after 4 × F. This depletion of sperm represents 64% of those considered available for ejaculation. The data indicate that the ductus deferentia and ampullae of rabbits contain insufficient sperm to account for those normally found in a single ejaculum, and that the caudae epididymides are the immediate sources of most ejaculated sperm. The average calculated daily sperm production (82 × 106) was not affected by ejaculation freq

ISSN:0003-276X    

DOI:10.1002/ar.1091580308

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractThe ependyma of the lateral ventricle of normal adult rats fixed by intravascular perfusion with either glutaraldehyde or formaldehyde was examined with the electron microscope. Three main observations of the normal ependymal cells were made which, to our knowledge, have not yet been reported.1Ependymal cells were occasionally found directly abutting on blood vessels in the immediate vicinity. In this respect, they were very much like the well‐known perivascular astrocytes and tanycytes. This similarity was strengthened by the morphological details of the junctional areas.2Bundles of the fine fibrils (app. 60 Å) were seen in the nuclei. They were devoid of any membranous boundary and were apparently identical to the fibrils often seen in the perinuclear cytoplasm.3Microtubules, occasionally containing approximately 50 Å central densities, were consistently seen in the apical cytoplasm. They were apparently identical to the familiar microtubules constituting the cillary fine structure which also contained occasional central densit

ISSN:0003-276X    

DOI:10.1002/ar.1091580309

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractTwo separate experiments were carried out. (1) Alloxan was injected subcutaneously into ICR female mice at 200 mg/kg on day 0 (zero) of gestation. In the animals which became persistently diabetic, 27.5% of the conceptuses underwent resorption or death and 7.2% of surviving fetuses showed gross malformations, including exencephaly, spina bifida and cleft palate. In nondiabetic experimental animals there was no increase in fetal mortality or malformation rate. (2) Wistar rats were treated by alloxan intraperitoneally at 160 mg/kg on the seventh day of gestation. Again, only in cases of persistent diabetes were there raised fetal mortality and high incidence of external and internal malformations (50.0% of survivors abnormal), including cataract, hydronephrosis, microphthalmia, exencephaly and cleft palate. When glucose concentration was determined in the embryo and amniotic fluid on the eleventh and thirteenth days of gestation, it was found to be much higher in the diabetic than in the control or the nondiabetic treated animals. The embryonic glucose level was always slightly lower than that of the maternal blood.

ISSN:0003-276X    

DOI:10.1002/ar.1091580310

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractIn both negatively stained and sectioned preparations, Golgi apparatus of mouse spleen, liver and kidney consist of dictyosomes having cisternae with tubular peripheries. The extent of the tubular portion varies among tissues and among cisternae of a given dictyosome. Animal dictyosomes closely resemble those from plants in both form and sedimentation characteristics. In these respects, plant and animal Golgi apparatus are homologous structures.

ISSN:0003-276X    

DOI:10.1002/ar.1091580311

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY