Figure 1

Percent of total slowly conducting, broad spiking afferents. A: Examples of action potentials generated from a fast conducting, broad spiking afferent (“A”-fiber) and a slowly conducting, broad spiking afferent (“C”-fiber) during development. From the onset of the electrical stimulus (arrows), the initiation of the “A”-fiber action potential was approximately twice as fast as the “C”-fiber potential. B: The percentage of mechanically sensitive, but thermally insensitive “C”-fibers (CM) out of all C-fibers recorded were significantly reduced beginning at postnatal day 10 (P10). C: Conversely, the percentage of mechanically sensitive and heat sensitive (and sometimes cold/cooling responsive) “C”-fiber afferents (CPM) was significantly increased beginning at P10. *p value < 0.05, χ².