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
    Comparative Quantitative Morphology of the Mammalian Lung: Diffusing Area (1963)
    [s.l.] : Nature Publishing Group
    Nature 197 (1963), S. 54-56 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] THE relationship between structure and function remains a central problem for all students of Nature. Classical comparative anatomy is rich with examples of form uniquely adapted to some circumstance of life; but quantitative morphology from a comparative point of view has been only slightly ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/197054a0
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Fictive respiratory rhythm in the isolated brainstem of frogs (1995)
    Springer
    Journal of comparative physiology 176 (1995), S. 703-713 
    Details
    ISSN: 1432-1351
    Keywords: Neural control of breathing ; Amphibian ; Isolated brainstem ; Respiration Pattern generation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Spontaneous rhythmically bursting activity was recorded from the trigeminal, vagal and hypoglossal nerve roots of the isolated brainstem from the frogsRana catesbeiana andRana pipiens superfused with a bicarbonate-free HEPES-buffer solution. Burst frequency, burst duration and the activity profile of the spontaneous neural discharges in vitro resembled those of a less radical preparation, the decerebrate, fictively breathing frog. After complete midsagittal section, each half of the isolated brainstem generated its own rhythmic neural activity which resembled that of the intact isolated brainstem. The spontaneous activity generated within each half of the brainstem is probably coordinated by decussating axons or by groups of neurons located along the midline of the brainstem. Our results suggest that these coordinating entities extend the length of the brainstem (in a rostro-caudal dimension) and the degree of contact rather than the location of the contact between the two halves of the brainstem determines the synchronization of the right and left halves. Burst frequency of both the intact and hemisected brainstem preparation was decreased by alkaline challenge and increased by acid challenge. We conclude that this endogeneous rhythmic activity represents the efferent motor output underlying lung ventilation in these animals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01021590
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Characterization of respiratory-related neurons in the isolated brainstem of the frog (1997)
    Springer
    Journal of comparative physiology 181 (1997), S. 153-159 
    Details
    ISSN: 1432-1351
    Keywords: Key words Amphibian ; Neural control of breathing ; Respiration ; Rhythm generation ; Isolated brainstem
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Using intra- and extracellular recording techniques we examined the spontaneous discharge and membrane properties of respiratory-related neurons in isolated brainstem preparations of the frogs Rana catesbeiana and Rana pipiens that display spontaneous respiratory related activity in vitro. We observed neurons that depolarize during the fictive lung ventilation cycle as well as neurons that depolarize during the non-lung ventilation phase. Respiratory-related neurons demonstrated significant decreases in membrane input resistance during the fictive lung ventilation cycle but showed no evidence of voltage-dependent membrane conductances activated near resting membrane potential. Furthermore, respiratory neurons showed little spike frequency adaptation, their oscillatory activity was not dissociated from the global respiratory motor output following imposed changes in membrane potential, and spontaneous fluctuations in membrane potential were not observed following reversible interruption of respiratory burst activity by application of solutions low in calcium and high in magnesium. Taken together these results suggest that bulbar respiratory neurons in the isolated frog brainstem sampled in our study do not display endogenous bursting characteristics. Rather, they are strongly influenced by synaptic input.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003590050102
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Two regions in the isolated brainstem of the frog that modulate respiratory-related activity (1995)
    Springer
    Journal of comparative physiology 177 (1995), S. 135-144 
    Details
    ISSN: 1432-1351
    Keywords: Pressure injection ; Neural control of breathing ; Amphibian ; Respiratory rhythmogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Using microinjection techniques, we have explored the isolated, complete midline sectioned brainstem of the frog (Rana catesbeiana) to identify regions that influence the endogenous respiratory-related motor activity. Ten-nanoliter injections of lidocaine (1%), GABA (100 mM) and glutamate (10 and 100 mM) into discrete regions of the rostral and the caudal brainstem produced different effects on the phasic neural discharge. In the rostral site lidocaine, GABA and glutamate injections altered neural burst frequency with little or no effect on burst amplitude. In the caudal site, responses to lidocaine and GABA injections consisted primarily of decreases in neural burst amplitude, often, but not always associated with minor decreases in burst frequency. In this same region, the response to glutamate was characterized by a temporary interruption of the rhythmic neural burst activity. The largest responses to substance injection in both regions were obtained at sites ranging between 200 and 500 μm from the ventral surface, in the ventral medullary reticular formation. The results reveal the existence of two areas in the frog brainstem that influence respiratory motor output, one related to the respiratory burst frequency and the other related to the amplitude of the motor output.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225094
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Fictive respiratory rhythm in the isolated brainstem of frogs (1995)
    Springer
    Journal of comparative physiology 176 (1995), S. 703-713 
    Details
    ISSN: 1432-1351
    Keywords: Neural control of breathing ; Amphibian ; Isolated brainstem ; Respiration Pattern generation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Spontaneous rhythmically bursting activity was recorded from the trigeminal, vagal and hypoglossal nerve roots of the isolated brainstem from the frogs Rana catesbeiana and Rana pipiens superfused with a bicarbonate-free HEPES-buffer solution. Burst frequency, burst duration and the activity profile of the spontaneous neural discharges in vitro resembled those of a less radical preparation, the decerebrate, fictively breathing frog. After complete midsagittal section, each half of the isolated brainstem generated its own rhythmic neural activity which resembled that of the intact isolated brainstem. The spontaneous activity generated within each half of the brainstem is probably coordinated by decussating axons or by groups of neurons located along the midline of the brainstem. Our results suggest that these coordinating entities extend the length of the brainstem (in a rostro-caudal dimension) and the degree of contact rather than the location of the contact between the two halves of the brainstem determines the synchronization of the right and left halves. Burst frequency of both the intact and hemisected brainstem preparation was decreased by alkaline challenge and increased by acid challenge. We conclude that this endogeneous rhythmic activity represents the efferent motor output underlying lung ventilation in these animals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00192499
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Reflex prolongation of stage I of expiration (1986)
    Springer
    Pflügers Archiv 407 (1986), S. 190-198 
    Details
    ISSN: 1432-2013
    Keywords: Respiratory rhythm ; Postinspiratory phase ; Apneic states ; Tachypneic states ; Medullary respiratory neurons ; Laryngeal afferents ; Pulmonary afferents ; Carotid sinus afferents
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Experiments were performed on anesthetized cats to test the theory that the interval between phrenic bursts is comprised of two phases, stage I and stage II of expiration. Evidence that these represent two separate neural phases of the central respiratory rhythm was provided by the extent to which stage duration is controlled individually when tested by superior laryngeal, vagus and carotid sinus nerve stimulation. Membrane potential trajectories of bulbar postinspiratory neurons were used to identify the timing of respiratory phases. Stimulation of the superior laryngeal, vagus and carotid sinus nerves during stage I of expiration prolonged the period of depolarization in postinspiratory neurons without significantly changing the durations of either stage II expiratory or inspiratory inhibition, indicating a fairly selective prolongation of the first stage of expiration. Changes in subglottic pressure, insufflation of smoke into the upper airway, application of water to the larynx or rapid inflation of the lungs produced similar effects. Sustained tetanic stimulation of superior laryngeal and vagus nerves arrested the respiratory rhythm in stage I of expiration. Membrane potentials in postinspiratory, inspiratory and expiratory neurons were indicative of a prolonged postinspiratory period. Thus, such an arrhythmia can be described as a postinspiratory apneic state of the central oscillator. The effects of carotid sinus nerve stimulation reversed when the stimulus was applied during stage II expiration. This was accompanied by corresponding changes in the membrane potential trajectories in postinspiratory neurons. The results manifest a ternary central respiratory cycle with two individually controlled phases occurring between inspiratory bursts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00580675
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The differential organization of medullary post-inspiratory activities (1987)
    Springer
    Pflügers Archiv 410 (1987), S. 420-427 
    Details
    ISSN: 1432-2013
    Keywords: Medullary respiratory neurones ; Respiratory rhythm generation ; Post-inspiratory activity ; Pulmonary afferents ; Laryngeal afferents
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Membrane potential trajectories of 68 bulbar respiratory neurones from the peri-solitary and peri-ambigual areas of the brain-stem were recorded in anaesthetized cats to explore the synaptic influences of post-inspiratory neurones upon the medullary inspiratory network. A declining wave of inhibitory postsynaptic potentials resembling the discharge of postpinspiratory neurones was seen in both bulbospinal and non-bulbospinal inspiratory neurones, including alpha- and beta-inspiratory, early-inspiratory, late-inspiratory and ramp-inspiratory neurones. Activation of laryngeal and high-threshold pulmonary receptor afferents excited bulbar post-inspiratory neurones, whilst in the case of inspiratory neurones such stimulation produced enhanced postsynaptic inhibition during the same period of the cycle. Activation of post-inspiratory neurones and enhanced post-inspiratory inhibition of inspiratory bulbospinal neurones was accompanied by supression of the after-discharge of phrenic motoneurones. These results suggest that a population of post-inspiratory neurones exerts a widespread inhibitory function at the lower brain-stem level. Implications of such an inhibitory function for the organization of the respiratory network are discussed in relation to the generation of the respiratory rhythm.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00586520
    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...