Library

X
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
    Electronic Resource
    Electronic Resource
    Properties of mesencephalic reticulospinal neurons in the cat (1980)
    Springer
    Experimental brain research 41 (1980), S. 75-78 
    Details
    ISSN: 1432-1106
    Keywords: Mesencephalic reticulospinal neurons ; Conduction velocities ; Vestibular system, semicir cularcanal inputs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Neurons that project to the spinal cord were located in the mesencephalic reticular formation outside the interstitial nucleus of Cajal in cerebellectomized cats under chloralose anesthesia. Of these neurons 40% responded only at C1 (reticulospinal N cells) and the remaining 60% responded at C4 also (reticulospinal D cells). Conduction velocities of N cells were significantly slower than those of D cells. N cells and D cells responded similarly to stimulation of the whole vestibular nerves and vestibular nuclei. However, they differ in semicircular canal inputs; N cells were more responsive to canal stimulation. Comparison of properties between mesencephalic reticulospinal and interstitiospinal neurons (Fukushima et al. 1980) showed that many reticulospinal and interstitiospinal neurons have similar properties, suggesting that functionally similar neurons may be found distributed over more than one anatomically defined cell group.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236681
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Effects of stimulation of frontal cortex, superior colliculus, and neck muscle afferents on interstitiospinal neurons in the cat (1981)
    Springer
    Experimental brain research 44 (1981), S. 143-153 
    Details
    ISSN: 1432-1106
    Keywords: Interstitiospinal neurons ; Pericruciate cortex ; Frontal eye fields ; Superior colliculus ; Neck muscle afferents
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Interstitiospinal neurons were activated by antidromic stimulation of the spinal cord ventromedial funiculus at C1 and C4 in cerebellectomized cats under chlor alose anesthesia. Neurons responding only to C1 were classified as N cells and those responding both to C1 and C4 were classified as D cells, as in previous experiments (Fukushima et al. 1980a). Vestibular branching interstitiospinal and reticulospinal neurons were also identified as in the previous experiments. Stimulation of the ipsilateral pericruciate cortex evoked firing in 31% of N cells, 41% of D cells and 35% of vestibular branching neurons, while stimulation of the contralateral cortex excited 6% of N cells, 29% of D cells and 14% of vestibular branching neurons. Response latencies ranged from 2 to 15 ms after the effective pulse. By measuring the thresholds of activation of these neurons while changing the depth of the stimulating electrodes, and by mapping the cortical areas, it was shown that the lowest threshold areas were in the frontal eye fields and the anterior sigmoid gyrus near the presylvian sulcus (Area 6). Stimulation of the latter area often evoked neck or shoulder muscle contraction. Stimulation in the deep layers of the ipsilateral superior colliculus evoked firing in about 20% of interstitiospinal neurons and about 42% of vestibular branching neurons, with typical latencies 2–3 ms after the effective pulse, while stimulation of the contralateral superior colliculus was rarely effective. N cells and D cells responded similarly. Thresholds for activation were high in the intermediate tectal layers and declined as the electrodes entered the underlying tegmentum. This suggests that the superior colliculus is not the main source of synaptic inputs to these neurons. Low threshold points were found above the deep fiber layer when stimulating electrodes were inserted into the pretectum. Stimulation of the C2 biventer cervicis nerve excited about 8% of N cells, 18% of D cells, and 15% of vestibular branching neurons bilaterally with typical latencies around 10 ms. Similar results were obtained when C2 splenius nerves were stimulated. The fibers responsible for such excitation are probably group II, since stimuli stronger than 1.8 times threshold of the lowest threshold fibers were needed to evoke excitation. Response decrement was often observed when stimuli were repeated at 1/s, while no such decrement was observed at the rate of 1/3 s. When the convergence of cortical and labyrinthine excitatory inputs was studied, 36% of interstitiospinal neurons received single inputs either from the pericruciate cortex or from the labyrinth, 22% of neurons received convergent excitation from both and the remaining 42% did not respond to either stimulus. Although vestibular branching neurons rarely received labyrinthine inputs, they frequently showed convergence of excitation to stimulation of the frontal cortex, superior colliculus and vestibular nuclei.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237335
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Vestibular responses and branching of interstitiospinal neurons (1980)
    Springer
    Experimental brain research 40 (1980), S. 131-145 
    Details
    ISSN: 1432-1106
    Keywords: Interstitiospinal neurons ; Vestibular system ; Semicircular canal inputs ; Axon branching
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Interstitiospinal neurons were activated by antidromic stimulation of the ventromedial funiculus of the spinal cord at C1 and C4 in cerebellectomized cats under chloralose anesthesia. 46% of these neurons responded only at C1 (N cells) and the remaining 54% responded at C4 also (D cells). There is no topographical difference in the location of N and D cells. Conduction velocities of N cells were significantly slower than those of D cells. 2. Stimulation of the contralateral whole vestibular nerve evoked firing of 31% of both N and D cells; some responded early enough to suggest disynaptic connections, many responded late. Stimulation of the ipsilateral whole vestibular nerve evoked firing of several cells, one spontaneously discharging D cell was inhibited. 3. Stimulation of the contralateral individual semicircular canal nerves evoked firing of 33% of N cells and 13% of D cells. Most of these responses were late. N cells responded not only to the vertical canals but also to the horizontal canal, whereas D cells responded to the horizontal canal, but seldom to the vertical ones. Most canal responding neurons received specific input, only two N cells received convergent input from both the anterior and horizontal canals. Stimulation of the ipsilateral canals did not evoke excitation of any cells tested; one D cell was inhibited by stimulation of the horizontal canal nerve. 4. Stimulation of the rostral medial vestibular nucleus evoked characteristic negative field potentials centered in the contralateral interstitial nucleus of Cajal (INC). Approximately 60% of both N and D cells received excitation from the contralateral vestibular nuclei. About 17% of these responding neurons received monosynaptic excitation, most frequently from the rostral medial nucleus. Stimulation of the ipsilateral vestibular nuclei evoked firing of 12% of both N and D cells. 5. Twenty-nine neurons were fired antidromically by weak stimuli applied to the ipsilateral vestibular nuclei. Twenty-seven of the 29 were activated only from C1 and were found in the INC (10 cells) and in the reticular formation dorsal to the INC (19 cells). Measurement of the spread of the effect of stimulus current and comparison of latencies to stimulation of the vestibular nuclei and C1 indicated that these neurons have axon collaterals going to the ipsilateral vestibular nuclei. Only one of them received excitation from the contralateral posterior canal, others did not respond to the labyrinth. Some were activated by stimulation of the vestibular nuclei.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237531
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Prolamellar body and saponins: Avenacosides are not constituents of Avena etioplasts (1983)
    Springer
    Plant cell reports 2 (1983), S. 148-151 
    Details
    ISSN: 1432-203X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Etiolated Avena leaf cells were homogenized, then fractionated into four fractions in the presence of salts by differential centrifugation, and intact etioplasts were prepared by Percoll or sucrose density gradient centrifugation. Using thin layer chromatography steroidal saponins, avenacoside A and B were found in the leaf cells and heavy cell fractions which were rich in other cell structures besides intact etioplasts, but not detected in the purified etioplasts. We concluded that saponins are not constituents of the prolamellar bodies in etioplasts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00269341
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Thickening process of polyethylene single crystals at an early stage of annealing (1984)
    Springer
    Colloid & polymer science 262 (1984), S. 597-604 
    Details
    ISSN: 1435-1536
    Keywords: position sensitive proportional counter ; small and wide angle X-ray scattering ; polyethylene single crystal ; annealing ; thickening
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract By the use of a position sensitive proportional counter, changes in small and wide angle X-ray scattering during annealing of polyethylene single crystal mats were measured from the start in successive spans of very short measuring time. At high temperatures, the long period relating to stacking of lamellae rapidly increased at an early stage, passed through a plateau, and thereafter again increased gradually. With a decrease in annealing temperature, the amount of its first rapid increase was reduced and the plateau changed into an ascending slope. At much lower annealing temperatures, the long period increased following the logt law after an induction time. The integral breadth of a peak corresponding to the long period first increased rapidly, simultaneously with the rapid increase in the long period, and thereafter decreased. Wide angle X-ray measurement showed that the integrated intensity of 110 reflection first decreased and then increased during annealing at high temperatures. This fall and rise process was more marked, when the annealing temperature is higher and the initial thickness of lamellae is smaller. From these observations, it was inferred that in the thickening process, stacking order of lamellae at first decreased because of rapid reorganization due to partial melting or melt-recrystallization and subsequently increased through increasing evenness of lamellar thickness.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01452449
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Polymerization of ethylene induced by fractured metallic oxides. III. Factors affecting the polymerization (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 29 (1984), S. 3401-3408 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Mechanochemical polymerization of ethylene was found to be induced by fracture of γ-alumina under quite low pressure and room temperature. The factors to control the polymerization yield, for example, calcination temperature of the alumina, spin concentration after ball milling, milling time, and changes of acidity before and after the fracture, were investigated in order to know the polymerization mechanism. It was found that the polymerization yield did correlate not with the spin concentration responsible to paramagnetic species produced by the fracture, but the calcination temperature of the γ-alumina and the milling time. The resultant polymeric material on the fractured alumina was extracted alumina was extracted with solvents, and the fraction extracted with petroleum ether was characterized using GC and GC mass spectrometer. The results indicated that odd-numbered linear hydrocarbons were produced, although the major products of this polymerization were even-numbered. It is concluded from the accumulated experimental results that a carbonium ion mechanism rather than radical mechanism is probable for the mechanochemical polymerization induced by fracture of γ-alumina.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1984.070291117
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Mechanochemical polymerization of acetylene (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 29 (1984), S. 3445-3455 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Gamma alumina, γ-Al2O3, was fractured in an atmosphere of acetylene monomer at room temperature to test whether they would be polymerized by mechanochemistry method on the surface of the alumina. The experimental results were obtained by serveral different methods, including CP-MAS 13C-NMR, ESR, pressure drop measurements of the monomer, optical absorption spectroscopy, and solvancy. The results proved the mechanochemical polymerization of acetylene monomer on surfaces of the fractured alumina. Several other combinations of either silica and acetylene monomer or polymers and acetylene monomer were tested for mechanochemical polymerization. This process proceeded with less efficiency in the silica system but no mechanochemical polymerization of acetylene was found in the combinations of the polymers and acetylene monomer.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1984.070291121
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...