“…After peripheral nerve (PN) lesions, synthesis of NGF, BDNF, NT-4, and GDNF increases (Meyer et al, 1992;Funakoshi et al, 1993;Trupp et al, 1995;Naveilhan et al, 1997;Bar et al, 1998;Hoke et al, 2000Hoke et al, , 2002Dethleffsen et al, 2002). Because NGF and GDNF stimulate axonal growth from DRG neurons in vitro and in vivo (Edström et al, 1996;Naveilhan et al, 1997;Leclere et al, 1998;Gavazzi et al, 1999;Ramer et al, 2000;Fine et al, 2002), their upregulation in lesioned peripheral nerves might be expected to promote axonal regeneration.…”