ISSN:0003-276X    

DOI:10.1002/ar.1091960102

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

年代:1980

数据来源: WILEY

摘要:

AbstractExperimental conditions simulating the induction of clinical pituitary gigantism and acromegaly were established by prolonged administration of growth hormone in high dosage to adult male rats starting at two different ages: 6 months (growth still active) and 14½ months (growth virtually arrested). Treatment continued for 14½ months, controls receiving saline injections. Each group numbered eight at onset. Standardized x‐rays of skull were made in ventro‐dorsal and lateral planes, at onset, mid‐period, and end of the study. Representative dimensions of cranial and facial segments were measured, including lengths, widths, palate dimensions, gnathic and interzygomatic angles, and incisor curvature. Some related indices were calculated. Means and standard errors were computed, usually on five to eight rats (oldest controls: three only). The response pattern of overall skull length was most illustrative. Younger adult controls grew actively until 14 months of age (5%) while injected rats grew still faster (8%); thereafter, controls grew negligibly (1%) and injected rats only slightly (2%). Older controls showed negligible skull elongation from 14½ to 29 months of age, and growth hormone stimulated no gain. In the younger group, skull length gains were almost entirely in the facial region; cranium gained no length and widened only slightly. Cranial index increased slightly with the hormone. Facial (bizygomatic) width increased in both injected groups—proportionately in younger rats (to gigantism) and disproportionately in older rats. Palatal and dental growth followed facial patterns in both groups. Cranial vault bones thickened and, in older rats, developed surface irregularities, giving them a more massive, acromegaloid

ISSN:0003-276X    

DOI:10.1002/ar.1091960103

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

年代:1980

数据来源: WILEY

摘要:

AbstractInsectivorous bat embryos (TadaridaandMyotis) ranging from 6‐to 16‐mm C‐R length were examined for the presence of the nervus terminalis. These embryos have no vomeronasal nerve with which the nervus terminalis could be confused. The nerve and associated ganglion cells first appear in the 7‐mm embryo. As the embryo ages, a gradual increase in nerve size and ganglion cell numbers occurs. In the 13‐mm embryo, nerve size and ganglion cell numbers are reduced, and in older embryos both nerve and cells are absent, as in the adult. The ganglion cells arise as clusters from the nasal septal epithelium. The largest number of cell clusters occurs in the 10.5‐mm embryo. Their number then decreases and none are present in embryos of 13‐mm and longer. These cells migrate centrally along the course of the nerve which accompanies the olfactory nerve from the nasal cavity roof to a level just caudal to the olfactory bulb, where the nervus terminalis turns dorsalward along the medial telencephalic wall surface. Except in the youngest and oldest embryos the nervus terminalis, where present, divides into two or three branches to pierce the hemispheric wall, one usually entering the region of the nucleus olfactorious anterior, and the other(s), the region of the medial septal nucleus. In some cases, several ganglion cells are present along the intrahemispheric course of the nerve fibers. All ganglion cells resemble those in various sensory ganglia, and so, are probably also se

ISSN:0003-276X    

DOI:10.1002/ar.1091960104

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

年代:1980

数据来源: WILEY

摘要:

AbstractAscending axons in the dorsal column of garter snakes were examined following hemisection of the spinal cord at segment levels 2, 3, 4, 11, 13, and 31. After postoperative survival periods of 11 to 28 days, sections of the spinal cord and brain were processed with a silver method to demonstrate degenerated axons and preterminals.The study demonstrated that most ascending degenerated axons are located in the outer half of the dorsal column. The somatotopic pattern of ascending fibers is evident, whereby dorsomedial fibers are primarily of caudal origin and the more dorsolateral axons are from rostral cord segments. Rostral to segment 31, all spinal segments appear to project to a strip of dorsal column adjacent to the dorsal median septum. From the septum, axons descend to terminate somatotopically on cells of the nucleus of Bischoff located caudal to the obex of the medulla.Dorsal column degeneration ascends to the level of the dorsal column nuclei, where most fibers terminate. Degeneration from caudal cord segments terminates on caudo‐medial cells of the dorsal column nuclei, while rostral cord segments project to rostro‐lateral cells. The dorsal column nuclei consist of an expanded lateral part between tractus descendens trigemini and the vago‐solitary complex, and a contiguous, thin medial lamina of cells dorsal and medial to the vagal nuclei. The somatotopic pattern of degeneration in the dorsal column nuclei, probably of dorsal root origin, follows the mammalian organization, which suggests that the garter snake has primitive nuclei gracilis and cuneatus. Other terminal sites of degenerating fibers, although probably of spinal gray origin, are nucleus commissura infima, nucleus descendens vestibuli, and area pos

ISSN:0003-276X    

DOI:10.1002/ar.1091960105

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

年代:1980

数据来源: WILEY

摘要:

AbstractCutting the suspensory ligament reduced the ovarian content of norepinephrine (NE) to less than half that of controls and only a few blood vessels had perivascular fibers and an occasional nerve remained in the interstitial gland. Cutting the ovarian plexus had a less drastic, but similar effect on the ovarian content of NE and on the pattern of ovarian adrenergic nerves. Cutting both the suspensory ligament and ovarian plexus eliminated visualization of ovarian adrenergic nerves, but some ovarian NE was still measurable. Fluorescence and electron microscopic studies of the suspensory liagament revealed a large adrenergic nerve embedded in smooth muscle of the ligament. The nerve was also acetylcholinesterase‐positive. Cutting the celiac plexus or incising a small nerve lateral to the plexus and medial to the origin of the suspensory ligament, had the same effect on the ovarian adrenergic nerves as cutting the suspensory ligament. It is concluded that the extrinsic adrenergic nerves to the rat ovary reach the organ by two routes: one via the nerve in the suspensory ligament (superior ovarian nerve), and one via the traditionally described ovarian plexus along the ovarian arter

ISSN:0003-276X    

DOI:10.1002/ar.1091960106

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

年代:1980

数据来源: WILEY

摘要:

AbstractThe postnatal differentiation of the hippocampal formation of theataxicmouse was studied. Brains fromataxicmice (axJ/axJ) and littermate controls (+/?), from 19 to 51 days of age, were either impregnated according to a Golgi‐Cox procedure or sectioned and stained with Weil‐hematoxylin and Darrow Red. The hippocampus and dentate gyrus, although somewhat reduced in cross‐sectional area in theataxicbrain, appeared to have a normal complement of both pyramidal cells and granule cells, respectively. Examination of Golgi‐Cox material showed significant differences in the differentiation of the dendritic tree of both pyramidal and granule cells. At 41 days the height of the apical dendrite of CA1 pyramidal cells in theataxicbrain was 76% of the control value, and the width was only 35%. Similarly, the basal dendritic tree was narrower in theataxicmouse. In the dentate gyrus of the 41‐dayataxicbrain, the height of the granule cell dendritic tree was only 74% of the control value. These and other alterations in the dendritic morphology of both CA1 pyramidal cells and granule cells can be explained by a lack of growth of the dendritic tree during the developmental period studied. These findings are discussed in relation to other studies on intrinsic and extrinsic factors and their effect on normal hippocampal differ

ISSN:0003-276X    

DOI:10.1002/ar.1091960107

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

年代:1980

数据来源: WILEY

摘要:

AbstractBy using the method of quail‐to‐chick transplantation of neural crest in one series (VNG) and placodal ectoderm in a second series (VPG) we were able to determine the relative contribution of cranial neural crest and placodal ectoderm to the formation of the Glossopharyngeal‐vagal complex. In chimeric embryos, quail cells originating from cranial neural crest grafts of postotic levels end up in the root ganglia, while quail cells originating from placodal ectoderm of postotic levels end up in the trunk ganglia. The results clearly indicate that the caudal levels of the medulla and rostral cervical segments represent the site, and the neural crest the source, for the neurons of the root ganglia. The neurons form a homogenous population of the small‐cell type. This clearly rules out any contribution to the root ganglia from placodal ectoderm. On the basis of our experiments, it is also concluded that the neurons of the trunk ganglia are purely placodal in origin and are composed of a population of cells of the large‐cell type. Our experiments also provide convincing evidence for a neural crest origin for Schwann cell and ganglionic Satell

ISSN:0003-276X    

DOI:10.1002/ar.1091960108

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

年代:1980

数据来源: WILEY

摘要:

AbstractThroughout stage VII and early stage VIII of the cycle of the seminiferous epithelium, the heads of the late spermatids, located in a juxtaluminal position, are embedded in apical processes of Sertoli cells. These processes contain cisternae of endoplasmic reticulum (ER) of two main types, i.e., flattened and tubular, which communicate with each other to form a continuous system. Throughout the long stage VII of the cycle, these two types of cisternae undergo marked changes. Inearlystage VII, the flattened cisternae, developing from the subsurface cisternae which compose the “junctional specialization,” form concentric sheets at the periphery and in the middle of each apical process. The less conspicuous tubular cisternae form a continuous network which is present in the bridge connecting the Sertoli cell body to the apical process, and extends along the dorsal and ventral aspects of the spermatid's head to end up as cup‐shaped flattened cisternae capping the bulbs of the tubulobulbar complexes described by Russell and Clermont ('76). Inmidstage VII, the flattened cisternae start to regress, while the tubular cisternae become more abundant. Inlatestage VII, only fragments of the flattened cisternae are present, while the tubular cisternae form a profuse and elaborate network throughout the apical process. In the following stage VIII, the tubular cisternae disperse and only remnants of ER are present at the time of the release of the spermatid into the tubular lumen. These transformations of ER cisternae suggest a complex alteration in the relationship between Sertoli cells and late spermatids prior to their release as sperma

ISSN:0003-276X    

DOI:10.1002/ar.1091960109

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

年代:1980

数据来源: WILEY

摘要:

AbstractIn bone marrow of the mouse perfused with fixative containing tannic acid and glutaraldehyde, gap junctions were observed between certain cell types. Gap junctions were seen between adjacent reticular cells, between adjacent macrophages, and between macrophages and reticular cells. Macrophages formed gap junctions with immature neutrophils, eosinophils, monocytes, and erythroblasts. Often a single macrophage had gap junctions with neutrophilic, eosinophilic, and monocytic cells; these blood cells varied from immature to nearly mature forms. In contrast, the macrophages associated with erythroblasts had gap junctions only with erythroblasts and all the erythroblasts were in the same developmental stage. The possible role of the gap junctions in differentiation and mobilization of marrow cells is discussed.

ISSN:0003-276X    

DOI:10.1002/ar.1091960110

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

年代:1980

数据来源: WILEY

ISSN:0003-276X    

DOI:10.1002/ar.1091960101

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

年代:1980

数据来源: WILEY