Long-Standing Motor and Sensory Recovery following Acute Fibrin Sealant Based Neonatal Sciatic Nerve Repair

Figure 10

Representative ultrastructure micrographs showing synapses opposed to α-motoneurons, following P2 sciatic nerve transection and repair. (a) Terminal intermingled with an astrocyte projection (glial cell), following axotomy without repair. (b, c) Observe a close to normal synaptic apposition in neurorrhaphy groups, AX+FS and AX+CFS, respectively. (d) Contralateral side. Scale bar = 500 nm. (e) Quantitative ultrastructural analysis of synaptic covering. (f) Detailed quantitative analysis of F, S, and C terminals. (g) Synaptic covering with normalized number of boutons per 100 μm of motoneuron membrane. Observe a reduction in synaptic covering following axotomy alone, 4 weeks after lesion. (h, i, j, k) Distribution of gap length between clusters of terminals apposing to motoneuron membrane in all groups analyzed. Observe that normal neurons (k) present presynaptic terminals close to each other, not exceeding 1.4 μm gap. Nerve lesion without repair results in longer gaps between terminals (h) and nerve coaptation reduced such distances (i, j; red rectangles). AX: axotomy; AX+FS: axotomy followed by neurorrhaphy with fibrin sealant derived from snake venom; AX+CFS: axotomy followed by neurorrhaphy with commercial fibrin sealant. Mean SE.

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