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
    Cat Distal Forelimb Joints and Locomotion: An X-ray Study (1991)
    Oxford, UK : Blackwell Publishing Ltd
    European journal of neuroscience 3 (1991), S. 0 
    Details
    ISSN: 1460-9568
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The complex construction of the joint apparatus of the cat distal forelimb, which allows the paw three degrees of freedom, poses special requirements on the neural signals controlling the paw position. To understand the electromyography (emg) signals of the distal forelimb muscles during locomotion, it is necessary to know the kinematics of the forelimb joints in detail. As no such information is available, we used the pulsed X-ray technique in trained cats during treadmill locomotion to analyse the angular excursions of the wrist, the metacarpophalangeal (MCP) and the proximal interphalangeal (PIP) joints. X-ray illuminations were done in either the parasagittal or the frontal plane. At the beginning of the stance phase the wrist (WR) and the MCP joints extended slowly, and the PIP joints flexed. Whereas the WR and the PIP joints maintained a constant angular position of ∼200° and 60°, respectively, throughout the stance phase, extension continued in the MCP joints from 240° at touch-down to 300° at the end of the stance phase. Slightly before lift-off (100 ms) the WR and the MCP joints flexed rapidly. This flexion changed ∼150 ms after lift-off into a slow extension. The PIP joints extended rapidly at the beginning and at the end of the swing phase, during the interposed period of the swing phase they displayed a slow flexion. Rotatory movements of the forelimb in the radioulnar joints were present during the swing and stance phases. During the swing phase the limb first supinated (starting 100 ms after lift-off); pronation occurred immediately before ground contact. During the stance phase the supination angle was kept constant until 100 ms before lift-off, when a short pronation was found. The paw was kept in an ulnar deviated position throughout the complete step cycle. Ulnar deviation decreased at the end of the swing and stance phases. The results of this study increase our understanding of how the body weight is transmitted on to the ground. They suggest four main functions for the skeletomotor apparatus and the underlying neural commands to secure the forward movement of the animal during the stance phase: (i) preparation and stabilization of a force-transmitting platform; (ii) stabilization of the wrist and the carpal/metacarpal joints; (iii) stabilization of the supination angle; (iv) antigravity control of the extension in the MCP.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1460-9568.1991.tb00807.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Efferent Pattern of Fictive Locomotion in the Cat Forelimb: with Special Reference to Radial Motor Nuclei (1990)
    Oxford, UK : Blackwell Publishing Ltd
    European journal of neuroscience 2 (1990), S. 0 
    Details
    ISSN: 1460-9568
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: In immobilized decerebrate cats fictive locomotion was evoked by midbrain stimulation to analyse the efferent pattern to elbow and to distal forelimb muscles innervated by the deep radial nerve. The locomotor activity was assessed by recording nerve discharges and motoneuronal membrane potential changes. The elbow flexor and extensor motoneurons showed a reciprocal activity; the membranes were correspondingly depolarized and hyperpolarized. In the motor nuclei to the wrist and digit extensors the active phases changed systematically according to the radio-ulnar order of the muscles: the extensor carpi radialis (ECR) was flexor-coupled, the ulnaris (ECU) extensor-coupled, the digitorum communis (EDC), the lateralis (EDL) and the indicis proprius (EIP) displayed intermediate patterns. Intracellular recordings from these motoneurons revealed in all motor nuclei, except ECR, a double depolarization. The first occurred early and the second later in the flexor phase; a hyperpolarization was interposed. The second depolarization mainly determined the active phase. According to the radio-ulnar order of the muscles the onset and termination of the second depolarization were delayed. This was presumably due to the interposed hyperpolarization, which progressively increased in amplitude. The ECR exhibited a single depolarization, into which the double depolarization apparently merged. The other radial motor nuclei, supinator (Sup) and Abductor pollicis longus (APL) displayed complex patterns. Sup showed tonic discharges, flexor-type discharges or discharges extending both into the flexor and extensor phase, APL showed discharges similar to either EIP or Sup. Membrane potential changes were small in APL and Sup. Thus, the central locomotor network generates differentiated efferent activities in the distal forelimb muscles, the radio-ulnar order of the muscles being important for the generated pattern.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1460-9568.1990.tb00456.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Shaping of the cat paw for food taking and object manipulation: an X-ray analysis (1998)
    Oxford, UK : Blackwell Science Ltd
    European journal of neuroscience 10 (1998), S. 0 
    Details
    ISSN: 1460-9568
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The kinematics of the cat distal forelimb during food-taking were analysed to obtain information on the movement processes within the paw before and during object taking in a species without monosynaptic cortico-motoneuronal projections. The behaviour was investigated with two tests: either the table test (TT, food offered on a table located at ground level in a reaching distance of 22 and 28 cm) or the horizontal test (HT, food offered in a small container located at shoulder level, height 18–25 cm, reaching distance 6–12 cm). In five animals, the changes in configuration and the conjoint actions of the wrist, the metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints were assessed with three-dimensional X-ray cinematography (time resolution 20 ms, spatial resolution 1 mm) and video analysis.While approaching the target, the digits were first extended and subsequently abducted. This ‘preshaping' consisted of combined angular changes in the MCP and PIP joints, thereby attaining an adequate grip aperture. Each cat used a stable strategy, but different cats used different strategies. In the TT, preshaping involved an MCP extension and a PIP flexion. In the HT, predominant extension of the MCP, predominant extension of the PIP, or a combination of both were used, followed by MCP flexion and PIP flexion. The grip aperture started to decrease before object contact, earlier in the TT, later in the HT. Grasping was achieved by flexion of first the PIP and later the MCP.The X-ray analysis gave evidence for individuated digit movements. Correlation analysis of the angular position of the joints between the different phalanges showed that digits 3 and 4 acted in concert, as did digits 2 and 5, but with clear independence between the different pairs. Furthermore, the different phalanges served different purposes during the grasp. Digits 3, 4 established object contact, digits 2, 5 were mainly used to stabilize the paw onto the surface.The cat distal forelimb displays a refined movement repertoire during the preshaping and grasping phase of food-taking. During the preshaping phase, the kinematics resembled in some aspects the situation in humans. The results demonstrate the ability of the polysynaptic projections from the cortico-motoneuronal system to organize differentiated distal limb movements, including individuated movements of the digits.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1460-9568.1998.00399.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    X-Ray Study of the Cat Hindlimb During Treadmill Locomotion (1994)
    Oxford, UK : Blackwell Publishing Ltd
    European journal of neuroscience 6 (1994), S. 0 
    Details
    ISSN: 1460-9568
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: With pulsed X-ray cinematography we have analysed the angular excursions of the distal hindlimb joints (proximal interphalangeal, PIP; metatarsophalangeal, MTP; ankle) in cats walking on a treadmill. These distal joints transmit the body weight and the dynamic forces onto the ground. We have included the knee and hip joints in the analysis to relate the angular excursions of the proximal and distal joints and to verify the data previously obtained with external markers on the kinematics of the proximal joints. At the beginning of the stance phase the PIP joints flexed rapidly, the MTP joints extended slowly and the ankle and knee yielded under body weight. Whereas the PIP joints maintained a rather constant angular position of −75° throughout the stance phase, extension continued in the MTP joints from −230° at touch-down to −270° at the end of the stance phase. Around 50 ms before lift-off the MTP joints flexed rapidly. Early (−30 ms) after lift-off this flexion changed into a slow extension. The PIP joints extended swiftly at the stance-swing transition and moderately at the end of the swing phase. During the middle part of the swing phase they flexed slowly. Small rotatory movements around the long axis of the foot took place in the last 100 ms of the swing phase. The results of this study on the distal joints are discussed in relation to the placing of the paw, to the translation of forward propulsion into a MTP movement and to the lifting of the paw (conventionally described as toe curling). They show a differentiated mechanical interaction between the different distal limb joints during these different phases, which must be known in detail to interpret the corresponding electromyographic data and to understand how the hip is moved forward over the MTP joints which serve as the final pivot during stance.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1460-9568.1994.tb00617.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    X-ray kinematic analysis of forelimb movements during target reaching and food taking in the cat (2000)
    Oxford, UK : Blackwell Science Ltd
    European journal of neuroscience 12 (2000), S. 0 
    Details
    ISSN: 1460-9568
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: We have used a three-dimensional X-ray cinematographic approach to investigate the kinematics of the forelimb during target reaching and food taking in five cats. Measurements of the trajectory of the limb during the reaching movement showed that the movement paths of the metacarpophalangeal joint (MCP) and the wrist were sigmoidal with a long nearly linear segment. The elbow followed a bent movement path with maximal inflection in the middle. The path of the humerus had an ascending parabola-like characteristic. The velocity profiles of the MCP and wrist were nearly bell-shaped and skewed to the left, whereas the profiles of the elbow joint were more or less double peaked with the second peak occurring 60–40 ms before object contact. Several different velocity peaks reflecting specific aspects of the task existed when the bell-shaped velocity profiles were divided in their vectorial components. Angular motion of the elbow consisted of a flexion–extension sequence during the reach and a flexion during the subsequent retraction. After an initial flexion during lift-off the wrist was extended. It kept this extended position during orienting towards the food container. During the retraction phase it was further extended. The angle between the wrist axis and the parasagittal plane changed during the movement. It first increased, then decreased during the last 100 ms before the object was reached. During the retraction it increased again to support the object weight against gravity. The position of the wrist was established by radio-ulnar supination and movements of the whole arm around the shoulder joint. We hypothesize that the position of the wrist axis is the controlled variable during protraction and retraction, regardless of whether it is achieved by radio-ulnar supination or by movements around the shoulder.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1460-9568.2000.00073.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    X-ray kinematic analysis of shoulder movements during target reaching and food taking in the cat (1999)
    Oxford, UK : Blackwell Science Ltd
    European journal of neuroscience 11 (1999), S. 0 
    Details
    ISSN: 1460-9568
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Co-ordinate movements around the shoulder are essential during reaching movements. We performed a quantitative kinematic analysis of movements of the shoulder girdle: three-dimensional X-ray frames (time resolution 20 ms) were recorded during the target-reaching and food-taking paradigm in five cats either sitting (n = 4) or standing (n = 1) in front of a food well. Movements of the scapula consisted of a flexion of the scapula (anteversion of the glenoid) followed by flexion of the gleno-humeral joint (decrease in the angle between the scapular spine and humerus). In the sitting animals, the gleno-humeral flexion reversed to extension some 120 ms before object contact, while in the standing animal flexion continued during the ongoing scapular flexion. In both cases, the scapula was nearly horizontal at the end of target reaching. The fulcrum for scapular movements was located near the vertebral border of the scapula at the medial elongation of the scapular spine. No major translational components of the fulcrum with respect to the trunk were found during reaching. Together with full flexion of the scapula, this reduces the number of degrees of freedom considerably and thereby probably simplifying the specification of the end-point of the limb chain. End-point specification is further supported by rotational movements of the scapula. In the sitting animal, the amplitude of inward rotation along the long axis of the scapula was around 20 °, while it was much more variable in the standing animal, reflecting more variable starting positions. We hypothesize that the glenoid is used to ‘foveate' the target object.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1460-9568.1999.00507.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Kinematic Analysis of the Cat Shoulder Girdle during Treadmill Locomotion: an X-ray Study (1996)
    Oxford, UK : Blackwell Publishing Ltd
    European journal of neuroscience 8 (1996), S. 0 
    Details
    ISSN: 1460-9568
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: A quantitative kinematic analysis of the movements of the shoulder girdle in the three dimensions of space during treadmill locomotion (velocity range 0.33–1.2 m/s) was performed in two cats. Since the movement patterns of the scapula and the humeroscapular joint can only vaguely be estimated through the overlying skin we used implanted metal spheres placed on the scapula in combination with three-dimensional pulsed X-ray cinematography (time resolution 20 ms) to reconstruct the excursions of the scapula, the humerus and the elbow and to calculate the respective angular amplitudes and velocities. The movements of the scapula relative to the Th4 spinous process consist of four major components: (i) a monophasic flexion (caudocranial movement of the glenoid fossa during swing)/extension (craniocaudal movement of the glenoid fossa during stance) sequence, the fulcrum for which sequence is situated near the vertebral border of the scapula at the medial elongation of the scapular spine; (ii) a vertical monophasic up/down sequence of the fulcrum relative to the trunk, the highest vertical position being reached during mid-stance and the lowest vertical position during mid-swing; (iii) a biphasic abduction/adduction sequence during swing and during stance respectively; and (iv) small rotations along the scapular spine. The trajectory recordings of the scapula indicate that the scapula yields relative to the trunk under the body weight after ground contact. The angular excursions of the humeroscapular joint consist of: (i) a flexion/extension sequence during swing, a yield after ground contact and a final extension at the end of stance; (ii) an adduction and outward rotation during the early swing phase flexion; (iii) an abduction and inward rotation during the late swing phase extension; and (iv) an adduction during the yield with only minor rotations during the whole stance phase. The movement patterns are discussed in view of the muscular synergies necessary to guide the scapula and the humerus during stance and swing, and in relation to the implications for the organization of these patterns in spinal neuronal systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1460-9568.1996.tb01210.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Integration in descending motor pathways controlling the forelimb in the cat (1977)
    Springer
    Experimental brain research 29 (1977), S. 323-346 
    Details
    ISSN: 1432-1106
    Keywords: Cortico-, rubro- and tectospinal tracts ; Forelimb afferents ; Short propriospinal neurones ; Forelimb motoneurones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A previously described disynaptic pathway from cortex to forelimb motoneurones whose intercalated neurones were excited both from other descending pathways and from forelimb afferents (Illert et al., 1976a, b) has been further analysed, mainly with respect to the location of the relay cells and their axons. Disynaptic EPSPs evoked in forelimb motoneurones by stimulation of the pyramid remained after complete transection of the corticospinal tract in C5 rostral to the forelimb segments but were abolished after a more rostral transection of the tract in the C2 segment. Corresponding findings were made with disynaptic rubral EPSPs after transection of the rubrospinal tract in these segments. It is concluded that disynaptic cortico-motoneuronal and rubro-motoneuronal excitation is relayed by propriospinal neurones originating in the C3–C4 segments. Other lesion experiments revealed that the axons of these propriospinal neurones descend to forelimb motoneurones in the ventrolateral part of the lateral funicle. Spatial facilitation of transmission from the corticospinal and rubrospinal tracts after transection of them in C5 occurred with a time course showing monosynaptic convergence from these pathways on common propriospinal neurones. Facilitation of disynaptic pyramidal EPSPs from the dorsal tegmentum remained after transection of the corticospinal tract at C5 but was abolished after a transection at C2. It is postulated that corticospinal and presumed tectospinal fibres converge onto common neurones in the propriospinal relay but evidence is also given for a more rostral relay (probably bulbar) with a similar convergence. The oligo- (probably mono-)synaptic facilitation of the disynaptic pyramidal EPSP evoked by volleys in cutaneous and group I muscle afferents from the forelimb likewise remained after a C5 transection of the corticospinal tract but was abolished after an additional C5 lesion in the dorsal column. It is concluded that propriospinal relay cells receive excitatory action from forelimb afferents ascending in the dorsal column. Spatial facilitation experiments using three tests revealed that propriospinal neurones monosynaptically excited from both corticospinal and rubrospinal fibres also receive excitation from cutaneous forelimb afferents. It is postulated that the propriospinal relay provides an important route for fast activation of forelimb motoneurones from the brain. The convergent monosynaptic excitation from several important motor centres in the brain is considered in relation to the general problem of the functional relationship between higher motor centres. The convergent action from forelimb afferents is taken to suggest that a descending command for a forelimb movement can be modified from the forelimb while on its way to the motoneurones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236174
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Integration in descending motor pathways controlling the forelimb in the cat. 4. Corticospinal inhibition of forelimb motoneurones mediated by short propriospinal neurones (1978)
    Springer
    Experimental brain research 31 (1978), S. 131-141 
    Details
    ISSN: 1432-1106
    Keywords: Forelimb motoneurone ; Trisynaptic pyramidal IPSP ; Propriospinal neurone ; Ia inhibition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A previously described inhibitory trisynaptic cortico-motoneuronal pathway (Illert et al., 1976a) was analysed in order to identify the two relay stations. Intracellular recording was made from motoneurones to elbow muscles. Corticospinal fibres were stimulated in the contralateral medullary pyramid. Pyramidal IPSPs were abolished by a transection of the Corticospinal tract in C2 but remained after a corresponding lesion in C5. After a C5 lesion pyramidal volleys facilitated transmission in the Ia inhibitory pathway with a time course suggesting disynaptic excitatory action on the Ia inhibitory interneurones. The trisynaptic pyramidal IPSPs were depressed by volleys in the appropriate recurrent motor axon collaterals as would be expected if these IPSPs were mediated by Ia inhibitory interneurones. It is concluded that trisynaptic cortico-motoneuronal inhibition is evoked by consecutive activation of propriospinal neurones in C3-C4 and segmental Ia inhibitory interneurones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235810
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Integration in descending motor pathways controlling the forelimb in the cat (1978)
    Springer
    Experimental brain research 33 (1978), S. 101-130 
    Details
    ISSN: 1432-1106
    Keywords: Cortico-, rubro and tectospinal tracts ; Cervical primary afferents ; Monosynaptic EPSPs ; Propriospinal neurones C3-C4
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Recording was made in the C3-C4 segments from cell bodies of propriospinal neurones identified by their antidromic activation from more caudal segments. Monosynaptic excitatory effects from descending motor pathways and primary afferents were investigated by electrical stimulation of higher motor centres and peripheral nerves in the forelimb and neck. The cell bodies were located mainly laterally in Rexed's layer VII. Threshold mapping for single axons showed that they descend in the lateroventral part of the lateral funicle. Antidromic stimulation at different spinal cord levels showed that some neurones terminated in the forelimb segments, others in the thoracic cord or in the lumbar segments. Terminal slowing of the conduction velocity suggested axonal branching over some segments. Monosynaptic EPSPs were evoked in the neurones by stimulation of the contralateral pyramid, red nucleus and dorsal tegmentum-superior colliculus. It is concluded that corticospinal, rubrospinal and tectospinal fibres project directly to both short and long propriospinal neurones. There was marked frequency potentiation in tectospinal synapses. Convergence from two descending tracts was common and in half of the tested cells all three tracts contributed monosynaptic excitation. Experiments with collision of descending volleys and antidromic volleys from the brachial segments demonstrated that the corticospinal and rubrospinal monosynaptic projection to the propriospinal neurones is by collaterals from fibres continuing to the forelimb segments. Stimulation of cervical primary afferents in the dorsal column gave monosynaptic EPSPs in somewhat less than half of the tested propriospinal neurones. The further analysis with stimulation of forelimb nerves and C2-C3 dorsal rami showed that monosynaptic EPSPs may be evoked from low threshold cutaneous and group I muscle afferents in the forelimb and from C2-C3 neck afferents entering close to the spinal ganglia, possibly from joint receptors. Convergence from cervical afferents and at least two of the above descending tracts was common. It is postulated that the propriospinal neurones previously indirectly defined by their action on motoneurones as relaying disynaptic excitation from higher motor centres to forelimb motoneurones (Illert et al., 1977) belong to those neurones of the C3-C4 propriospinal systems which terminate in the cervical enlargement. The function of the neurones projecting beyond the upper thoracic segments is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238798
    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...