Majallah-i Dānishgāh-i ̒Ulūm-i Pizishkī-i Bābul (Oct 2007)
FINDINGS ABOUT THE NEUROPHYSIOLOGY OF MAMMALIAN MUSCLE SPINDLE SYSTEM
Abstract
The experiments were carried out on the muscle spindle (MS) that located onto the soleus muscle (SM) in the anaesthetized rats. After applying a mechanical slow stretch (SS) on the SM, the MS wasn influenced by this stimulant and it was in a slack status. On the other hand, the MS has showed a dysfunction. The slack status of MS, it means, without electro-mechanical activity for MS that was observed in isolating MS. And this slack status of MS also was occurred by insufficient of γ-motor stimulation. With using the passive stimulating vibration on the MS-SM, again, the slack status of MS was observed. Of course, in this experiment, before that the MS was made up with passive vibration, firstly, the activation of MS was clearly observed by γs-activity. On contrary of the positive effect of γs into MS, there wasn a positive effect with γd-activity into MS. But, its stated that, there was the resting discharge (RD) in the MS during slack status and the RD scale has been significantly acceptable. The MS-RD was created with both of the SS and especially by γs stimulation, though not with γd stimulation.However, it was concluded that, the changing of MS-activity could be caused with the changing length of SK.M. In this process, the MS respond was pertinent to γs-activity. Meanwhile, the activation of γs was followed by activity of MS- chain- afferent. Its seemed that, in this loop of nervo-muscular wasn any place for activating of MS-bag fiber.
