Suppression of collagen Q expression in the extrajunctional regions of rat fast muscles is encoded in their stem cells (satellite cells).

In rat fast muscles, collagen Q (ColQ) expression is restricted to the neuromuscular junctions. In contrast, it is high also extrajunctionally in the slow soleus muscles. Fast muscles activated by chronic low-frequency electrical stimulation, similar to neural activation of the soleus muscles, did not increase their extrajunctional expression of ColQ.