Abstract
Myosin heavy chain (MHC) expression is regulated by many factors including neural input. To gain a better understanding of myosin transformation following reinnervation we examined both MHC protein and mRNA in single fibers of the soleus. A midthigh sciatic nerve lesion resulted in reinnervation of the soleus by motoneurons from both the original and foreign motor pools. MHC expression was examined in individual fibers 8 and 16 weeks post injury using in situ histochemistry and immunohistochemistry. Following a sciatic nerve lesion, the reinnervated soleus underwent a transformation from slow toward fast based on physiologic and biochemical measurements. At 8 weeks, fast MHC mRNA isoforms (IIa and IIx) were upregulated and slow mRNA was downregulated, however, the predominant protein isoform was MHC I. At both 8 and 16 weeks, many fibers expressed multiple mRNA isoforms. At 16 weeks there was limited co-expression of slow and fast MHC mRNAs, but continued co-expression of fast MHC mRNAs. Sixteen weeks following reinnervation the predominant fast mRNA and protein in the soleus was IIx MHC.
Original language | English (US) |
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Pages (from-to) | 13-16 |
Number of pages | 4 |
Journal | Neuroscience Letters |
Volume | 215 |
Issue number | 1 |
DOIs | |
State | Published - Aug 30 1996 |
Externally published | Yes |
Keywords
- Denervation
- Immunohistochemistry
- In situ histochemistry
- Myosin heavy chain gene regulation
- Sciatic nerve injury
ASJC Scopus subject areas
- Neuroscience(all)