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The Langerhans cells are capable of taking up L-dopa and the catecholamines dopamine and noradrenaline when exposed to these substances in vitro. Within the cell L-dopa is found in the cytoplasm as well as in the nucleus, whereas the catecholamines are confined to cytoplasmic granules. The L-dopa uptake is most probably carrier-mediated and the hypothesis is brought forward that L-dopa enters the
The type of gland (salivary gland) described here for the amphipod Gammarus pulex belongs to the tegumental glands, which have different structural characteristics. The present type, called rosette gland, is common in some crustaceans and is located in the ventral half of the head. The functional unit is a lobule of gland cells with a central-draining duct. Ducts from groups of lobules conjoin and
The neuronal types and patterns in the visual system of the species Artemia salina and Daphina magna have been studied with the Golgi method and electron microscopy. The lamina contains five classes of neurons: photoreceptor axons, monopolar, centrifugal, tangential and amacrine neurons. The terminals of the receptor axons are distributed in two (A. salina) or three (D. magna) layers. The dilated
The crustacean species Pacifastacus leniusculus and Gammarus pulex were investigated by electron microscopy in a search for possible neuromuscular junctions in the hindgut, which has a rich supply of catecholaminergic fibres. True neuromuscular synapses were found in both species between nerve terminals containing dense-core vesicles (80–110 nm in diam.) and muscle fibres. We suggest that the dens
The isopod species Astacilla longicornis (Sowerby) has a layered rhabdom, which is the first case reported in isopod crustaceans. The rhabdom comprises the rhabdomeres of six retinular cells. It is surrounded by an extracellular palisade. Usually, palisades are intracellular in arthropods. A layered rhabdom is found in taxonomically widely separated groups within the Arthropoda and no intermediate
The compound eyes of the deep-sea mysid Boreomysis scyphops and the two mysid species Amblyops abbreviata and Pseudomma 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 cylinde
In certain sensory neurons of many different invertebrate species, including the sea anemones. Metridium senile and Tealia felina and the crustacean Anemia salina, fluorophores are formed during the course of the fluorescent histochemical technique of Falck-Hillarp. The presumed catecholamine nature of the neuronal fluorogenic compound was investigated by microspectrofluorometry, and the spectral In certain sensory neurons of many different invertebrate species, including the sea anemones. Metridium senile and Tealia felina and the crustacean Anemia salina, fluorophores are formed during the course of the fluorescent histochemical technique of Falck-Hillarp. The presumed catecholamine nature of the neuronal fluorogenic compound was investigated by microspectrofluorometry, and the spectral
The cellular localization of biogenic monoamines in crustaceans was studied by means of a highly specific and sensitive fluorescence method devised by Falck and Hillarp. It was found that neurons displaying specific fluorescence in the central nervous system were confined to the protocerebrum, the medulla externa and interna and the ventral nerve cord. The method allows a distinction between the f
Recent work on heritage and social media has highlighted how social media offer new possibilities for citizens to share memories, identities, local culture and heritage, and thus constitute a more participatory and democratic platform (Giaccardi 2012). Social media encourage and enable new forms of engagement and interpretations of the heritage through user-generated content, personal reflections,
The Internet, apart from being a fascinating field of study in its own right, has opened up new possibilities for scholars to get news, gather data, connect with informants, and in general stay updated on rapidly changing developments in Chinese society. Social media have added yet another dimension as it enables researchers to catch up with events and public debates as they unfold and get valuabl
The present work is a continuation of the morphological studies of the nauplius eye and frontal organs of the Crustacea. The previous papers on this topic comprised the Decapoda (ELOFSSON, 1963) and the Malacostraca (ELOFSSON, 1965). Its has been found that the nauplius eye and frontal organs of the Crustacea are separated into four different types. These comprise the Phyl-lopoda, Anostraca, Maxil
The nauplius eye and frontal organs in the Malacostraca have been investigated. The present work is a direct continuation of the author's investigation of the same organs in decapod malacostracans (Elofsson, 1963). The results obtained confirm the recognition of a nauplius eye sensu iatu and a nauplius eye sensu strictu. The former is a combination of the latter and the dorsal frontal organ. It oc
The present investigation concerns the nauplius eye and frontal organs in decapod Crustaceans. Representatives from all groups of the Decapoda are included. Some of the more important results are abstracted.The nauplius eye in several families within the Eucyphidea is more complicated than generally believed. It consists of a nauplius eye s. s. with three cups and three sensory cells in each and t
Pasiphaeid larvae collected in the Korsfjord, western Norway, were found to split up into two groups. Mainly two characteristics separated the larvae viz. the size of the larvae and the number of telson spines. The group with small larvae (8 to 10 mm) and the larger number of telson spines is referred to Pasiphaea multidentata and that with large larvae (10 to 12 mm) and fewer telson spines to Pas
