摘要:

Weanling rats of both sexes were submitted to either castration, or castration together with periodic injections of testicular extract to males or of ovarian extract to females. Control and experimental animals were sampled at 63 days of age. Cranial differentiation between sexes was estimated by Mahalanobis D2 distances. The controls showed a significant sexual cranial difference. Orchidectomy decreased cranial differences and this effect was compensated by injections of testicular extract. On the other hand, oophorectomy increased cranial differences, which were diminished by injections of ovarian extract. Sexual cranial dimorphism in the normal rat seems to be the result of a counteracting effect between testicular and ovarian hormonal secretions.

ISSN:1422-6405    

DOI:10.1159/000146596

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Small foci of diethylstilbestrol-induced extracellular hyaline material were visualized within the mouse uterus utilizing dark-field and fluorescence microscopy following conventional hematoxylin and eosin staining. Hyaline was observed throughout the connective tissue stroma as well as between smooth muscle cells of the myometrium. The use of these techniques permits the rapid examination of small aggregates of hyaline material which are not visible with conventional hematoxylin and eosin staining and eliminates the need for time-consuming and complicated histochemical techniques. The procedures are simple and may also facilitate the quantitative (morphometric) analysis of this material.

ISSN:1422-6405    

DOI:10.1159/000146597

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Somite formation involves a reorientation of the cells of the paraxial mesoderm but the underlying mechanism of this movement has never been demonstrated. The present investigation shows bundles of myofibril-like material in the ventrocranial corners of some of the paraxial mesoderm cells of Xenopus prior to reorientation and consequent somite formation.

ISSN:1422-6405    

DOI:10.1159/000146598

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The distributional pattern of serotonin-immunoreactive nerve fibers in the hippocampal formation of six different mammalian species (rat, chipmunk, hamster, cat, dog and monkey) was studied in detail by means of a modified peroxidase-antiperoxidase immunohistochemical method, using a specific serotonin antiserum. Furthermore, the density of varicosities distributed in each layer of the hippocampus was semiquantitatively analyzed. In all species investigated, the routes of serotonin fibers entering the hippocampal formation were found to be almost the same. These fibers were extensively distributed throughout the hippocampal formation, and had a characteristic arrangement corresponding to the laminar structure of this region. A dense innervation by varicose serotonin fibers was found in the stratum lacunosum-moleculare, but a few serotonin fibers were also distributed in the stratum lucidum of the CA2 and CA3 fields. The stratum pyramidale and the granule cell layer of the dentate gyrus contained a small number of serotonin fibers. The concentration and the direction of serotonin fibers were different in each area of each animal. Two peculiar observations should be stressed: (1) in the rat, the strata oriens and radiatum of CA2 and CA3 as well as the stratum lacunosum-moleculare displayed abundant serotonin fibers; (2) in the dog, abundant serotonin fibers were diffusely distributed in the CA1 field except for the stratum pyramidale and the most dense concentratioi > of serotonin fibers was seen in the stratum oriens of CA3.The present study provides a morphological basis for further study of the functional significance of serotonin in the limbic system.

ISSN:1422-6405    

DOI:10.1159/000146599

出版商:S. Karger AG    

年代:1988

数据来源: Karger

ISSN:1422-6405    

DOI:10.1159/000146600

出版商:S. Karger AG    

年代:1988

数据来源: Karger

ISSN:1422-6405    

DOI:10.1159/000146601

出版商:S. Karger AG    

年代:1988

数据来源: Karger

ISSN:1422-6405    

DOI:10.1159/000146602

出版商:S. Karger AG    

年代:1988

数据来源: Karger

ISSN:1422-6405    

DOI:10.1159/000146585

出版商:S. Karger AG    

年代:1988

数据来源: Karger