Fusimotor activity and the tendon jerk in the anaesthetised cat

Wood, S. A. ; Morgan, D. L. ; Gregory, J. E. ; Proske, U.
Springer
Published 1994
ISSN:
1432-1106
Keywords:
Tendon jerk ; Fusimotor ; Reflex Muscle spindle ; Cat
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract This is a study of the tendon jerk reflex elicited by a brief stretch applied to the triceps surae muscle group in the chloralose-anaesthetised cat. The size of the recorded reflex depended on stretch parameters (optimum at 300 μm amplitude at a rate of 100 mm/s) and on how the muscle had been conditioned. A reflex elicited after a conditioning contraction at the test length was often twice as large as after a contraction carried out at a length longer than the test length. This difference was attributed to the amount of slack introduced in the intrafusal fibres of muscle spindles by conditioning. The question was posed, did ongoing fusimotor activity exert any influence on the size of the tendon jerk? Depolarization indices (DPI) were calculated from responses of muscle spindles to stretch and correlated with the level of reflex tension. Values of DPI obtained from afferent responses with and without repetitive stimulation of identified fusimotor fibres suggested that with the stretch parameters used here the main influence of fusimotor activity was that it removed any pre-existing slack in muscle spindles and thereby increased reflex tension. In the absence of intrafusal slack, stimulation of static and dynamic fusimotor fibres had little additional influence on the size of the reflex. It is concluded that much of the variability typically seen with tendon jerks is due to muscle history effects. Since in muscles which have not been deliberately conditioned there is commonly some slack present in spindles, activity in fusimotor fibres is likely to reduce slack and therefore increase reflex size.
Type of Medium:
Electronic Resource
URL:
_version_ 1798295598806335489
autor Wood, S. A.
Morgan, D. L.
Gregory, J. E.
Proske, U.
autorsonst Wood, S. A.
Morgan, D. L.
Gregory, J. E.
Proske, U.
book_url http://dx.doi.org/10.1007/BF00229114
datenlieferant nat_lic_papers
hauptsatz hsatz_simple
identnr NLM202308847
issn 1432-1106
journal_name Experimental brain research
materialart 1
notes Abstract This is a study of the tendon jerk reflex elicited by a brief stretch applied to the triceps surae muscle group in the chloralose-anaesthetised cat. The size of the recorded reflex depended on stretch parameters (optimum at 300 μm amplitude at a rate of 100 mm/s) and on how the muscle had been conditioned. A reflex elicited after a conditioning contraction at the test length was often twice as large as after a contraction carried out at a length longer than the test length. This difference was attributed to the amount of slack introduced in the intrafusal fibres of muscle spindles by conditioning. The question was posed, did ongoing fusimotor activity exert any influence on the size of the tendon jerk? Depolarization indices (DPI) were calculated from responses of muscle spindles to stretch and correlated with the level of reflex tension. Values of DPI obtained from afferent responses with and without repetitive stimulation of identified fusimotor fibres suggested that with the stretch parameters used here the main influence of fusimotor activity was that it removed any pre-existing slack in muscle spindles and thereby increased reflex tension. In the absence of intrafusal slack, stimulation of static and dynamic fusimotor fibres had little additional influence on the size of the reflex. It is concluded that much of the variability typically seen with tendon jerks is due to muscle history effects. Since in muscles which have not been deliberately conditioned there is commonly some slack present in spindles, activity in fusimotor fibres is likely to reduce slack and therefore increase reflex size.
package_name Springer
publikationsjahr_anzeige 1994
publikationsjahr_facette 1994
publikationsjahr_intervall 8009:1990-1994
publikationsjahr_sort 1994
publisher Springer
reference 98 (1994), S. 101-109
schlagwort Tendon jerk
Fusimotor
Reflex Muscle spindle
Cat
search_space articles
shingle_author_1 Wood, S. A.
Morgan, D. L.
Gregory, J. E.
Proske, U.
shingle_author_2 Wood, S. A.
Morgan, D. L.
Gregory, J. E.
Proske, U.
shingle_author_3 Wood, S. A.
Morgan, D. L.
Gregory, J. E.
Proske, U.
shingle_author_4 Wood, S. A.
Morgan, D. L.
Gregory, J. E.
Proske, U.
shingle_catch_all_1 Wood, S. A.
Morgan, D. L.
Gregory, J. E.
Proske, U.
Fusimotor activity and the tendon jerk in the anaesthetised cat
Tendon jerk
Fusimotor
Reflex Muscle spindle
Cat
Tendon jerk
Fusimotor
Reflex Muscle spindle
Cat
Abstract This is a study of the tendon jerk reflex elicited by a brief stretch applied to the triceps surae muscle group in the chloralose-anaesthetised cat. The size of the recorded reflex depended on stretch parameters (optimum at 300 μm amplitude at a rate of 100 mm/s) and on how the muscle had been conditioned. A reflex elicited after a conditioning contraction at the test length was often twice as large as after a contraction carried out at a length longer than the test length. This difference was attributed to the amount of slack introduced in the intrafusal fibres of muscle spindles by conditioning. The question was posed, did ongoing fusimotor activity exert any influence on the size of the tendon jerk? Depolarization indices (DPI) were calculated from responses of muscle spindles to stretch and correlated with the level of reflex tension. Values of DPI obtained from afferent responses with and without repetitive stimulation of identified fusimotor fibres suggested that with the stretch parameters used here the main influence of fusimotor activity was that it removed any pre-existing slack in muscle spindles and thereby increased reflex tension. In the absence of intrafusal slack, stimulation of static and dynamic fusimotor fibres had little additional influence on the size of the reflex. It is concluded that much of the variability typically seen with tendon jerks is due to muscle history effects. Since in muscles which have not been deliberately conditioned there is commonly some slack present in spindles, activity in fusimotor fibres is likely to reduce slack and therefore increase reflex size.
1432-1106
14321106
Springer
shingle_catch_all_2 Wood, S. A.
Morgan, D. L.
Gregory, J. E.
Proske, U.
Fusimotor activity and the tendon jerk in the anaesthetised cat
Tendon jerk
Fusimotor
Reflex Muscle spindle
Cat
Tendon jerk
Fusimotor
Reflex Muscle spindle
Cat
Abstract This is a study of the tendon jerk reflex elicited by a brief stretch applied to the triceps surae muscle group in the chloralose-anaesthetised cat. The size of the recorded reflex depended on stretch parameters (optimum at 300 μm amplitude at a rate of 100 mm/s) and on how the muscle had been conditioned. A reflex elicited after a conditioning contraction at the test length was often twice as large as after a contraction carried out at a length longer than the test length. This difference was attributed to the amount of slack introduced in the intrafusal fibres of muscle spindles by conditioning. The question was posed, did ongoing fusimotor activity exert any influence on the size of the tendon jerk? Depolarization indices (DPI) were calculated from responses of muscle spindles to stretch and correlated with the level of reflex tension. Values of DPI obtained from afferent responses with and without repetitive stimulation of identified fusimotor fibres suggested that with the stretch parameters used here the main influence of fusimotor activity was that it removed any pre-existing slack in muscle spindles and thereby increased reflex tension. In the absence of intrafusal slack, stimulation of static and dynamic fusimotor fibres had little additional influence on the size of the reflex. It is concluded that much of the variability typically seen with tendon jerks is due to muscle history effects. Since in muscles which have not been deliberately conditioned there is commonly some slack present in spindles, activity in fusimotor fibres is likely to reduce slack and therefore increase reflex size.
1432-1106
14321106
Springer
shingle_catch_all_3 Wood, S. A.
Morgan, D. L.
Gregory, J. E.
Proske, U.
Fusimotor activity and the tendon jerk in the anaesthetised cat
Tendon jerk
Fusimotor
Reflex Muscle spindle
Cat
Tendon jerk
Fusimotor
Reflex Muscle spindle
Cat
Abstract This is a study of the tendon jerk reflex elicited by a brief stretch applied to the triceps surae muscle group in the chloralose-anaesthetised cat. The size of the recorded reflex depended on stretch parameters (optimum at 300 μm amplitude at a rate of 100 mm/s) and on how the muscle had been conditioned. A reflex elicited after a conditioning contraction at the test length was often twice as large as after a contraction carried out at a length longer than the test length. This difference was attributed to the amount of slack introduced in the intrafusal fibres of muscle spindles by conditioning. The question was posed, did ongoing fusimotor activity exert any influence on the size of the tendon jerk? Depolarization indices (DPI) were calculated from responses of muscle spindles to stretch and correlated with the level of reflex tension. Values of DPI obtained from afferent responses with and without repetitive stimulation of identified fusimotor fibres suggested that with the stretch parameters used here the main influence of fusimotor activity was that it removed any pre-existing slack in muscle spindles and thereby increased reflex tension. In the absence of intrafusal slack, stimulation of static and dynamic fusimotor fibres had little additional influence on the size of the reflex. It is concluded that much of the variability typically seen with tendon jerks is due to muscle history effects. Since in muscles which have not been deliberately conditioned there is commonly some slack present in spindles, activity in fusimotor fibres is likely to reduce slack and therefore increase reflex size.
1432-1106
14321106
Springer
shingle_catch_all_4 Wood, S. A.
Morgan, D. L.
Gregory, J. E.
Proske, U.
Fusimotor activity and the tendon jerk in the anaesthetised cat
Tendon jerk
Fusimotor
Reflex Muscle spindle
Cat
Tendon jerk
Fusimotor
Reflex Muscle spindle
Cat
Abstract This is a study of the tendon jerk reflex elicited by a brief stretch applied to the triceps surae muscle group in the chloralose-anaesthetised cat. The size of the recorded reflex depended on stretch parameters (optimum at 300 μm amplitude at a rate of 100 mm/s) and on how the muscle had been conditioned. A reflex elicited after a conditioning contraction at the test length was often twice as large as after a contraction carried out at a length longer than the test length. This difference was attributed to the amount of slack introduced in the intrafusal fibres of muscle spindles by conditioning. The question was posed, did ongoing fusimotor activity exert any influence on the size of the tendon jerk? Depolarization indices (DPI) were calculated from responses of muscle spindles to stretch and correlated with the level of reflex tension. Values of DPI obtained from afferent responses with and without repetitive stimulation of identified fusimotor fibres suggested that with the stretch parameters used here the main influence of fusimotor activity was that it removed any pre-existing slack in muscle spindles and thereby increased reflex tension. In the absence of intrafusal slack, stimulation of static and dynamic fusimotor fibres had little additional influence on the size of the reflex. It is concluded that much of the variability typically seen with tendon jerks is due to muscle history effects. Since in muscles which have not been deliberately conditioned there is commonly some slack present in spindles, activity in fusimotor fibres is likely to reduce slack and therefore increase reflex size.
1432-1106
14321106
Springer
shingle_title_1 Fusimotor activity and the tendon jerk in the anaesthetised cat
shingle_title_2 Fusimotor activity and the tendon jerk in the anaesthetised cat
shingle_title_3 Fusimotor activity and the tendon jerk in the anaesthetised cat
shingle_title_4 Fusimotor activity and the tendon jerk in the anaesthetised cat
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timestamp 2024-05-06T09:38:45.087Z
titel Fusimotor activity and the tendon jerk in the anaesthetised cat
titel_suche Fusimotor activity and the tendon jerk in the anaesthetised cat
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