Interaction of Norves and Muscles After Partial Denervation

Research Project

Project/Area Number	12832017
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Institution	Kanazawa University
Principal Investigator	TATENO Katsuhiko Medical department, prof., 医学部, 教授 (40092788)
Project Period (FY)	2000 – 2002
Project Status	Completed (Fiscal Year 2002)
Budget Amount *help	¥3,500,000 (Direct Cost: ¥3,500,000) Fiscal Year 2002: ¥400,000 (Direct Cost: ¥400,000) Fiscal Year 2001: ¥1,700,000 (Direct Cost: ¥1,700,000) Fiscal Year 2000: ¥1,400,000 (Direct Cost: ¥1,400,000)
Keywords	partial denervation / Spionting / Soleus muscle / ヒラメ筋 / 運動負荷 / 無負荷 / 神経発芽 / 神経・筋の相互作用 / 髄鞘内横断面積 / 筋横断面積
Research Abstract	The effects of partial denervation of the rat soleus and sciatic nerve were studied by resecting the right L5 nerve. The cross-sectinal areas of sciatic nerves and soleus muscles were examined with respect to the changes in muscle fiber types. The sciatic nerves and soleus muscles were removed 2,4,6 and 8 weeks after the operation. The soleus muscles were weighed immediately after removal and stained with routine ATPase staining, followed by examination of changes in type classification (Type II /Total muscle fibers) and cross-sectional areas. The cross-sectinal myelinated areas did not change in the control group. For the partial denervation group, an increase in the cross-sectional areas at 4 and 6 weeks were seen. An overall decrease in corerected muscle weight (soleus muscle weight mg/body weight g) was seen in the partial denervation group, but no changes were seen throughout the experimental week. The distribution of the cross-sectional area in partial denervated soleus muscle was shifted to the left at 2 weeks. The distribution began to par shift to the right at 4 weeks and there were biphasic left- and right-shifted groups at 6 weeks. Finally, the whole denervated group had shifted to the right by 8 weeks. The distribution of denervated muscles remained even throughout the 8 weeks. These findings indicate that, in the partially denervated muscle, recovery of the muscle atrophied through disuse and reinnervated muscle occurs first, followed by recovery of the remaining partially denervated muscle.