摘要:

AbstractTissues were processed for fluorescence microscopy of biogenic amines according to the method of Falck and Hillarp. Normal animals, and animals injected with α‐methylnoradrenaline or 5,6‐dihydroxytryptamine were used.Catecholaminecontaining neurons (junctional cells) occur in the innermost rows of cell bodies of the inner nuclear layer (INL) and close to the vitreous surface. Catecholamine containing fibers occur in three layers: (1) an outer layer around the innermost perikarya of the INL, which is a condition not found in retinas of gnathostome chordates; (2) a middle layer within the outer third of the inner synaptic layer (ISL), separated from the outer layer by ganglion cell axons; (3) a sparse inner layer within the innermost third of the ISL. A few catecholamine containing fibers were seen to extend from the innermost region of the INL to the outer synaptic layer. The position of the junctional cells in the lamprey corresponds to that in gnathostome chordates, but whereas all catecholamine containing fiber layers in gnathostomes are locatedsclerallyto the optic fiber layer and within the ISL, the middle and the inner fiber layers in the lamprey occurvitreallyto the optic fiber layer.Indoleamineaccumulating neurons occur in the innermost row of perikarya of the INL and close to the vitreous surface. Those of the INL send fine, varicose branches to the ISL forming a network which is somewhat denser at the inner and outer borders of the ISL than in its middle. The indoleamine accumulating terminals do not ramify within the INL in contrast to the catecholamine containing termi

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1977.tb00245.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

AbstractIn elasmobranchs (sharks, rays) the total weight of lymphomyeloid structures isolated by dissection varied between about 0.6 and 1.0% of the body weight. In a holocephalan (Chimaera) the corresponding value was 1.7%. Reciprocal size relations may exist between different types of lymphomyeloid organs. A thymus was found in adult specimens of rays (Raja) and the rabbit‐fish (Chimaera). The lymphomyeloid organs supposedly are active in haemopoiesis and the immune response

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1977.tb00246.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

AbstractViviparus bengalensis(Gastropoda: Prosobranchia) possesses a single bipinnate gill consisting of about 600 filaments. On account of large surface area, ciliation, polarized glycogen and alkaline phosphatase and an investing acid mucopolysaccharide layer, this organ is eminently suited to calcium ion uptake. In addition to this function, it is also secondarily an organ of calcium storage. This stored calcium is distinct from other forms of stored calcium already reported in that it is exceedingly susceptible to osmotic disturbances and very labile. It is possible that this serves as an almost instantaneously mobilizable reserve in times of calcium demand.

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1977.tb00247.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

AbstractChemical, histochemical and electron microscopic studies on the fibrous polysaccharide component of the test ofCiona intestinalisL. were made. The results showed cellulose‐like fibres to be present in the cuticle layer and in the ground substance. Bundles of fibres varying in diameter from 80 to 600 nm interweave to form a conspicuous network. The bundle appears to be formed of flat fibres, 10–13 nm in width, while the fibre is composed of fibrils 3.5–5 nm; the rectangular cross section of fibres can be supposed. The probable rôle of this polysaccharide is dis

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1977.tb00248.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

AbstractBasic hematological parameters of laboratory‐rearedLemmus lemmushave been investigated. The results have been summarized together with those from ten other species of microtine rodents. Climatic conditions, especially the microclimate of the subnivean air space, have been considered to offer possible explanations for the higher values inL. trimucronatuscompared toL. Lemmu

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1977.tb00249.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

AbstractThe respiratory epithelium in the lungs of the newtTriturus cristatushas been studied by electron microscopy. The entire pulmonary gas‐exchange area is covered by a continuous epithelium, the cells of which are all of the same type and are termed “pneumonocytes”. Typically each pneumonocyte is squamous and has attenuated sheets of cytoplasm which cover the pulmonary capillaries. Its free surface bears microvilli while mitochondria, multivesticular bodies and small inclusions are prominent in its cytoplasm. Many pneuomonocytes send cytoplasmic processes deep into the substance of the lung wall. It is postulated that these processes may help to anchor the epith

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1977.tb00250.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

AbstractThe fine structure of the dorsal longitudinal flight muscle of the monarch butterfly,Danaus plexippus(L.), is described. The high actin: myosin filament ratio in this fast muscle is likely related to extensive actin‐myosin filament interaction which must occur when tension is increased and maintained by repeated nervous stimulation as demonstrated by Kammer (1967) during the long downstroke of the wingbeat cycle.Glycogen particles are present in the granular fraction of the interfibrillar sacroplasm and among the myofilaments of the flight muscle of young butterflies. The distribution of the granules appears to be related to spatial forces within the muscle fibril for in resting butterflies the intermyofilament particles are generally located in rows parallel to the myofilaments, while they are in transverse bands in the H and I zones of animals fixed immediately after flight. Since the glycogen particles were not depleted during flight, this redistribution does not appear to be related to glycogen metabolism.Glycogen in the flight muscle was depleted during eight days of adulthood in butterflies fed on honey solutions, but lipid reserves increased in the same perio

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1977.tb00251.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

AbstractThe compound eyes of the deep‐sea mysidBoreomysis scyphopsand the two mysid speciesAmblyops abbreviataandPseudomma affine, which are indigenous to deep fiords in Norway, have been investigated. The eye stalks are greatly transformed, but contain hypertrophied retinas. The ommatidia of all three species lack a dioptric apparatus, possessing only retinular cells, which are arranged in a cylinder‐like fashion. Folds from the retinular cells project into the “cylinder” and are covered with microvilli. The arrangement is explained functionally by an increase in the photopigment‐bearing surface as an adaptation to low‐light intensities. The orderly arrangement of microvilli in most arthropod compound eyes has been lost, and the arrangement is thus multidirectional in these mysids. With the photopigment dipoles arranged along the microvillar axis, the disorderly arrangement of microvilli signifies a more efficient capture of non‐polarized light. It is concluded that the mysid compound eyes show adaptations to low‐light intensities probably acquired during the species' evolutionary descent into deep‐sea habitats.Amblyops abbreviataandPseudomma affine, belonging to genera with entirely transformed eyes and with an ultrastructure less “normal” than that ofBoreomysis scyphopsare believed to be earlier descendants into the deep‐sea habitats than the latter species, which belongs to a genus in which most of the species h

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1977.tb00252.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY