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  • 1985-1989  (4)
  • GC-MS  (2)
  • 52.80  (1)
  • Afferent synapses  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Synaptic input and local output of dopaminergic neurons in grafts that functionally reinnervate the host neostriatum (1987)
    Springer
    Experimental brain research 68 (1987), S. 131-146 
    Details
    ISSN: 1432-1106
    Keywords: Ventral mesencephalic grafts ; Electron microscopy ; Afferent synapses ; Tyrosine hydroxylase immunocytochemistry ; Dopaminergic neurons ; Dopaminergic boutons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In adult rats with a unilateral 6-hydroxydopamine-induced lesion of the nigrostriatal dopamine pathway, grafts of embryonic ventral mesencephalon can establish extensive efferent connections with the previously denervated host neostriatum and can compensate for motor and sensorimotor asymmetries induced by the lesion. The object of this study was to examine the afferent synaptic inputs to grafted dopaminergic neurons, implanted into a cortical cavity overlying the previously denervated caudate-putamen, using electron microscopic immunocytochemistry. The dopaminergic neurons of the grafts in the same animals had previously been shown to re-innervate the host neostriatum, to form synaptic connections therein and to attenuate the lesion-induced motor asymmetry that occured in response to amphetamine (Freund et al. 1985). In the light microscope, the grafts were found to contain numerous tyrosine hydroxylase-immunoreactive perikarya, dendrites, axons and axonal swellings which had distinct distributions. In addition axons and axonal swellings that were immunoreactive for either substance P or glutamate decarboxylase were present. Electron microscopic analysis of the boutons contacting tyrosine hydroxylase-immunoreactive neurons in the grafts revealed the presence of at least five distinct types of afferent synaptic boutons based on their immunochemistry, morphology, or types of membrane specialization. One type was itself immunoreactive for tyrosine hydroxylase; such synapses are extremely rare in the intact substantia nigra, none were found in the contralateral substantia nigrae or the substantia nigra of a control rat. Three of the remaining types had ultrastructural features that were similar to synaptic terminals that were immunoreactive for substance P or glutamate decarboxylase. These synapses were similar to the types of synapses found contacting dopaminergic neurons in the substantia nigra contralateral to the graft or the substantia nigra of a control rat. The results demonstrate that, in the absence of the normal extrinsic afferent inputs, the intracortical mesencephalic grafts have a well-developed local synaptic circuitry. It is suggested that local circuit regulation of dopaminergic neurons within the graft may, at least in part, be responsible for the maintenance of a normal or close to normal functional activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00255240
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    X-ray preionized CO2 laser (1985)
    Springer
    Applied physics 37 (1985), S. 219-221 
    Details
    ISSN: 1432-0649
    Keywords: 42.55D ; 33.80E ; 52.80 ; 42.60B
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A short pulse (100 ns) high-energy x-ray source has been used to preionize a transversely excited carbon dioxide gas discharge laser of 600 cm3 active volume. The maximum output power of 60 MW in a 50 ns FWHM pulse was achieved from a CO2−N2−He−CO−Xe static gas mixture at 600 Torr pressure. The energy conversion efficiency was 6%.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00692945
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Volatile components of scent material from cotton-top tamarin (Saguinus o. oedipus) (1988)
    Springer
    Journal of chemical ecology 14 (1988), S. 1367-1384 
    Details
    ISSN: 1573-1561
    Keywords: Primate ; callitrichids ; Saguinus o. oedipus ; chemical communication ; scent marking ; chemical analysis ; GC-MS ; volatile composition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The first chemical analysis of the volatile components of scent material from the cotton-top tamarin,Saguinus o. oedipus is presented. In contrast to our previous findings in saddle-back tamarins (Saguinus fuscicollis), the chemical composition of the scent marks is quite variable. Analysis of secretion expressed manually from different areas of the scent pads of sedated animals shows individual and regional variability. Only three components (squalene, cholesterol, andp-methoxybenzaldehyde) were found in all scent mark samples analyzed. However, suprapubic secretions obtained from one sedated female contained, in addition, 12 butyrate esters as well as five acetate esters which were homologous to the butyrates. The butyrate esters have been previously identified in scent material fromSaguinus fuscicollis. The variability of the composition of the scent material is discussed in relation to the scent-marking behavior of the cotton-top tamarins. Behavioral studies tested the ability of the cotton-top tamarins to discriminate between scent marks from conspecifics and scent marks from saddle-back tamarins. The group of 12 subjects discriminated between the scent marks from both species in choice tests during which they could freely contact the scent samples. However, when scent marks were presented under a screen, so that the subjects could smell but not contact the stimuli, no discrimination was shown. Four individuals displayed more interest in the screened scent stimuli than all other subjects. When these animals were tested in a second experiment for their ability to discriminate between material from the two species on the basis of only volatile cues, it became evident that they were able to do so. These results indicate that volatile cues alone enable the tamarins to recognize scent marks from conspecifics, but that additional cues perceived during contact with the scent are important for its full attractiveness and/or informational content.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01020141
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    Paper (German National Licenses)
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  • 4
    Electronic Resource
    Electronic Resource
    Analysis of chemical signals in a primate species (Saguinus fuscicollis): Use of behavioral, chemical, and pattern recognition methods (1986)
    Springer
    Journal of chemical ecology 12 (1986), S. 513-531 
    Details
    ISSN: 1573-1561
    Keywords: Chemical communication ; scent marking ; pattern recognition ; Saguinus fuscicollis ; GC-MS ; primate ; tamarin ; skin secretions ; n-butyrate esters ; concentration profiles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Scent marking with specialized skin glands is a common behavior in the tamarin,Saguinus fuscicollis. The scent marks identify species, subspecies, gender, and individual, and they also contain information on the social position and hormonal condition of an animal. The marks are chemically complex, containing a large number of compounds. Analysis by means of gas chromatography-mass spectrometry has identified 16 major components (squalene and 15 esters of butyric acid). These compounds are present in the marks of males and females of two subspecies,Saguinus f. fuscicollis andSaguinus f. illigeri. Application of computerized pattern recognition techniques has shown that concentration patterns of some of the butyrates are diagnostic of the two subspecies while concentration patterns of other butyrates are diagnostic of males and females regardless of subspecies. Behavioral studies have shown that the concentration patterns of butyrates and squalene alone do not encode information on subspecies and gender. It is, however, likely that this information is partially encoded by these specific butyrate-squalene concentration patterns but that yet unidentified compounds in the scent marks serve as necessary synergists.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01020570
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    Paper (German National Licenses)
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