Figure 7. The thin axons in muscle spindles are not sympathetic fibers.

Tyrosine hydroxylase (TH)-immunoreactive axons (light green in A, B; yellow in A',B') were seen close to muscle spindles and often over the capsule walls (c), but they were never seen among intrafusal muscle fibres. They were most often associated with blood vessels (*). Scale bars = 25 µm.