Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1573-7381
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Summary The distribution of serotonin-, tyrosine hydroxylase-, and FMRFamide-immunoreactive neuronal elements, as well as the concentrations of serotonin and dopamine in the different parts of the gastrointestinal tract, were studied in the snail Helix pomatia. The sensitivity of the spontaneous contractions of the alimentary tract to serotonin, dopamine, and FMRFamide was also tested. Serotonin-, tyrosine hydroxylase-, and FMRFamide-immunoreactive elements could be demonstrated in each part of the gastrointestinal tract, but they showed different innervation patterns. Serotonin- and tyrosine hydroxylase-immunoreactive elements were dominant in the submucosal layer, whereas FMRFamide-immunoreactive elements were dominant in both the mucosal and submucosal layers. Tyrosine hydroxylase-immunoreactive elements were confined to the longitudinal muscle trabeculae of submucosa, whereas serotonin-immunoreactive elements were distributed throughout the submucosal layer. No serotonin-immunoreactive cell bodies, but only fibers, could be detected in the gastrointestinal tract, and therefore they represent extrinsic elements. Tyrosine hydroxylase- and FMRFamide-immunoreactive cell bodies represent intrinsic elements of the tract. The occurrence and density of the serotonin- and tyrosine hydroxylase-immunoreactive elements showed significant differences in the different parts of the alimentary tract, in accordance with HPLC assays, which revealed a significant frontocaudal decrease in both the serotonin (from 2.11 to 1.21 pM/mg) and dopamine (from 3.28 to 0.52 pM/mg) contents of the different parts of the alimentary tract. Dopamine at 10-5 M concentration proved to be effective only on the longitudinal muscles by increasing the tone and frequency of contractions, but was ineffective on the circular muscles. Serotonin affected both the longitudinal and circular muscles. Serotonin at 10-5 M concentration decreased the tone and increased the frequency of low-amplitude contractions of the longitudinal muscles of the esophagus and the gizzard but increased both the tone and frequency of the crop. Serotonin at 10-9 M concentration slightly decreased the tone and blocked the contractions of the circular muscles in the crop but at 10-5 M concentration induced contractions of the circular muscles in the gizzard. FMRFamide at 10-6 M concentration decreased the tone and was shown to block the contractions of both the longitudinal and circular muscles.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of neurocytology 16 (1987), S. 613-626 
    ISSN: 1573-7381
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The synaptic input to crayfish (Orconectes limosus) stretch receptor neurons, and the synaptic interactions between the inhibitory and excitatory efferents were analysed by electron microscopy of serial sections. Several novel types of synaptic connections have been observed: (i) inhibitory synaptic input on the axon hillock and initial axon segment; (ii) serial synaptic terminals on the sensory cell body; (iii) simultaneous synaptic contacts of the same inhibitory terminal with sensory dendrites and muscle fibres; (iv) reciprocal synapses between the two types of inhibitory efferents; and (v) inhibitory synapses on the primary inhibitory axon. The possible functional significance of these synapses is discussed in the light of earlier electrophysiological and pharmacological findings.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 254 (1988), S. 369-379 
    ISSN: 1432-0878
    Keywords: Hindgut efferents ; Synapses ; HRP labeling ; Orconectes limosus (Crustacea)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution, morphology and synaptic connections of the hindgut efferent neurons in the last (sixth) abdominal ganglion of the crayfish, Orconectes limosus, have been investigated using light and electron microscopy in conjunction with retrograde cobalt/nickel and HRP labeling through the intestinal nerve. The hindgut efferent neurons occur singly and in clusters, and are unipolar. Their axonal projections are uniform and consist of a thick primary neurite with typical lateral projections and limited arborization of varicose fibers in the ganglionic neuropil. They also send lower order axon processes to the ganglionic neural sheath, where they arborize profusely, forming a network of varicose fibers. The majority of the efferent neurons project to the anterior part of the hindgut. HRP-labeled axon profiles are found in both pre- and postsynaptic position in the neuropil of the ganglion. HRP-labeled axon profiles also establish pre- and postsynaptic contacts in the intestinal nerve root. All hindgut efferent terminals contain similar synaptic vesicle populations: ovoid agranular vesicles (50–60 nm) and a few large granular vesicles (100–200 nm). It is suggested that the hindgut efferent neurons in the last abdominal ganglion are involved in: (1) innervation of the hindgut; (2) central integrative processes; (3) “en route” synaptic modification of efferent and afferent signals in the intestinal nerve; (4) neurohumoral modulation of peripheral physiological processes.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1432-0878
    Keywords: Key words Pigment-dispersing hormone ; Immunocytochemistry ; Central nervous system ; Gastropoda ; Helix pomatia ; Lymnaea stagnalis (Mollusca)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract By using an antiserum raised against a crustacean β-pigment-dispersing hormone (PDH), the distribution and chemical neuroanatomy of PDH-like immunoreactive neurons was investigated in the central nervous system of the gastropod snails, Helix pomatia and Lymnaea stagnalis. The number of immunoreactive cells in the Helix central nervous system was found to be large (700–900), whereas in Lymnaea, only a limited number (50–60) of neurons showed immunoreactivity. The immunostained neurons in Helix were characterized by rich arborizations in all central ganglia and revealed massive innervation of all peripheral nerves and the neural (connective tissue) sheath around the ganglia and peripheral nerve trunks. A small number of Helix nerve cell bodies in the viscero-parietal ganglion complex were also found to be innervated by PDH-like immunoreactive processes. Hence, a complex central and peripheral regulatory role, including neurohormonal actions, is suggested for a PDH-like substance in Helix, whereas the sites of action may be more limited in Lymnaea.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1573-6830
    Keywords: antipsychotic ; neuroleptic ; gastropod ; monoamine ; catecholamine ; serotonin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary 1. The effects of long term administration of micromolar concentrations of the D2 antagonist haloperidol upon monoaminergic neurons in the snailLymnaea stagnalis was investigated. 2. Treatment by bath application with 0.5–2.0 micromolar haloperidol, caused a significant, continuous depletion of dopamine levels in the nervous system as revealed by high performance liquid chromatography. 3. A transient depletion of serotonin was also observed, but DOPA and norepinephrine levels were unaffected. Similar depletion of dopamine was observed after the land snail,Achatina fulica, was injected with haloperidol on each of 4 consecutive days. 4. The depletion of dopamine as revealed with glyoxylate-induced fluorescence inLymnaea appears to be restricted to a subpopulation of catecholaminergic neurons which are immuno-negative for tyrosine hydroxylase, the synthetic enzyme responsible for the conversion of tyrosine to DOPA.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 134 (1972), S. 337-349 
    ISSN: 1432-0878
    Keywords: Median eminence of birds ; Thyrotrop function ; Neurosecretion ; Light-and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. The effects of TSH and PTU treatment with thyroid stimulating hormone and propylthiouracil on the structure of median eminence of the pigeon have been studied by light- and electron microscopy. 2. By light microscopy it has been found that the aldehydefuchsin positive material of the external layers of the anterior median eminence differs functionally from that of the neural lobe. 3. The light- and electron microscopic investigations revealed that the anterior and posterior median eminence differ both structurally and functionally. Specifically after the experimental interventions the considerable reaction can be observed only in the anterior median eminence. 4. Electron microscopically it appears possible that the aldehyde-fuchsin positive material of the anterior median eminence may be associated with the 1200–1500 Å—size granules. 5. The quantitative changes observed in the granular composition after the treatments show a close correlation with thyroid function, namely after treatment with thyroid stimulating hormone the relative quantity of the 1200–1500 Å—size granules increases markedly, while administration of propylthiouracil has the opposite effect and increases the relative quantity of the 1000 Å—size dense-core vesicles. They presumably may play a role in the control of TSH-secretion.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 189 (1978), S. 257-266 
    ISSN: 1432-0878
    Keywords: Neuromuscular junction ; Hindgut ; Crustacea ; Catecholamine ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 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 dense-core vesicle terminals contain a catecholamine, and this is supported by ultrahistochemical tests for monoamines. Two types of junctions are found: one in which the nerve terminal is embedded in the muscle cell (both species) and one in which protrusions from the muscle cell meet nerve terminals (Pacifastacus). Gammarus pulex, which has only circular muscles in the hindgut, has only catecholaminergic innervation, whereas Pacifastacus leniusculus has circular and longitudinal muscles both with at least two types of innervation.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1432-0878
    Keywords: Serotonin (5-HT) ; Genital chamber ; Immuno-cytochemistry ; Electron microscopy ; Cricket, Acheta domestica
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The serotonergic innervation of the genital chamber of the female cricket, Acheta domestica, has been investigated applying anti-serotonin (5-HT) immunocyto-chemistry at both light- and electron-microscopic levels as well as using conventional electron microscopy. Whole mount and pre-embedding chopper techniques of immuno-cytochemistry reveal a dense 5-HT-immunoreactive network of varicose fibers in the musculature of the genital chamber. All of these immunoreactive fibers originate from the efferent serotonergic neuron projecting through the nerve 8v to the genital chamber (Hustert and Topel 1986; Elekes et al. 1987). At the electron-microscopic level, 5-HT-immunoreactive nerve terminals, which contain small (50–60 nm) and large (∼ 100 nm) agranular vesicles as well as granular vesicles (∼100nm), contact the muscle fibers or the sarcoplasmic processes without establishing specialized neuromuscular connections. In addition to the 5-HT-immunoreactive axons, two types of immunonegative axons can also be found in the musculature. By use of conventional electron microscopy, three ultrastructurally distinct types of axon processes can be observed, one of which resembles 5-HT-immunoreactive axons. While the majority of the varicosities do not synapse on the muscle fibers, terminals containing small (50–60 nm) agranular vesicles occasionally form specialized neuromuscular contacts. It is suggested that the 5-HTergic innervation plays a non-synaptic modulatory role in the regulation circular musculature in the genital chamber of the cricket, while the musculature as a whole may be influenced by both synaptic and modulatory mechanisms.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1432-0878
    Keywords: Serotonin ; Dopamin ; Immunocytochemistry ; Terminal ganglion ; Acheta domestica
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution and ultrastructure of serotonin- and dopamine-immunoreactive (5-HTi and DAi) neurones have been investigated in the terminal ganglion of the cricket, Acheta domestica, using a pre-embedding chopper technique. Special attention has been paid to the immunoreactive structures in the neuropil. 5-HTi structures are extensively distributed and densely packed throughout the 5 neuromeres of the terminal ganglion and originate from several interneurones and efferent neurones. In contrast, DAi fibres are distributed sparsely although they extend to all neuromeres of the ganglion and originate from 6 interneurons only. For both 5-HTi and DAi neurones characteristic axonal projections and branching patterns can be distinguished. The 5-HTi axons exhibit rich varicose arborizations, whereas DAi neurones possess fewer varicosities in the neuropil. Electron microscopy shows that 5-HTi varicosities contain small (∼ 60 nm) and large (∼ 100 nm) agranular vesicles, and large (∼ 100 nm) granular vesicles, whereas in DAi varicosities small (∼ 60 nm) agranular and large (∼ 100 nm) granular vesicles are seen. Both 5-HTi and DAi varicosities form synaptic contacts. We conclude that both serotonin and dopamine may be used as neurotransmitters in the terminal ganglion of the cricket.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1432-0878
    Keywords: Serotonin (5HT) ; Immunocytochemistry ; 5,6-Dihydroxytryptamine ; Central nervous system ; Helix pomatia (Mollusca)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of serotonin (5HT)-containing neurons in the central nervous system of the snail Helix pomatia has been determined in whole-mount preparations by use of immunocytochemical and in vivo 5,6-dihydroxy-tryptamine labelling. 5HT-immunoreactive neuronal somata occur in all but the buccal and pleural ganglia. Immunoreactive fibres are present throughout the central nervous system. The 5HT-immunoreactive neuronal somata characteristically appear in groups, located mainly in the cerebral, pedal, visceral and right parietal ganglia. The majority of 5HT-immunoreactive neurons is located in the pedal ganglia. Additionally a dense network of 5HT-immunoreactive varicose fibres is found in the neural sheath of the central nervous system including all the nerves and ganglia. The number and distribution of 5HT-immunoreactive neurons correlates with that demonstrated by 5,6-dihydroxytryptamine labelling method.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...