Endogenous NGF and nerve impulses regulate the collateral sprouting of sensory axons in the skin of the adult rat

We have investigated the co-involvement of endogenous NGF and impulses in the collateral sprouting of cutaneous sensory nerves in adult rats, specifically the A delta-axons involved in mechanonociception and the C-fibers that mediate heat nociception. Their collateral sprouting was measured by the progressive expansion, respectively, of the behaviorally defined "pinch" and "heat" fields into surrounding denervated skin (the light-touch A …