[Influence of 100 Hz sinusoidal vibration on muscle spindle afferents of soleus muscles in suspended situation rat].
OBJECTIVE
To study influence of 100 Hz sinusoidal vibration on muscle spindle afferents discharges of rat soleus muscles in simulated-weightlessness situation.


METHODS
The tail-suspended rat model was used to simulate weightlessness, and 100 Hz sinusoidal vibration was performed by a vibrator. Unit activity was recorded electrophysiologically from the centrally cut filaments of the spinal dorsal roots innervating muscle spindles of the rat soleus muscle; then observation on the changes in afferent discharges from muscle spindle in a rat soleus muscles were made after 7 d.


RESULTS
1) Compared with control muscle spindle afferents discharges of rat soleus muscles decreased after 7 d tail-suspension (P<0.05). 2) Compared with suspension the afferent discharges from soleus muscle spindles increased after 7 d tail-suspension with 100 Hz sinusoidal vibration.


CONCLUSIONS
Sinusoidal vibration (100 Hz; 300 micrometers) can selectively activate muscle spindles. Muscle spindle afferent input of the suspended rats increased after the application of 7 d 100 Hz sinusoidal vibration.
Ren
Jun-chan
JC
Department of Physiology, Medical College of Xi'an Jiaotong University, Xi'an, China.
Fan
Xiao-li
XL
Song
Xin-ai
XA
Li
Qiang
Q
D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D019417:Hindlimb Suspension; D009470:Muscle Spindles / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D009475:Neurons, Afferent / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D014732:Vibration; D018474:Weightlessness Simulation