All animals received C3 dorsal column wire knife lesions and BMSC grafts mixed with NT-3 protein. Lentivirus for expression of NT-3 or GFP were injected at the same time rostral to the lesion site. Rolipram and mesopram infusions (2.6 mg/kg/day) were started 1 week prior to C3 lesions, pumps were exchanged at the time lesions were made, and infusions continued for one additional week. Conditioning lesions were done 1 week prior to C3 dorsal column lesions (preconditioning) or 1 or 7 days after C3 lesions (post-conditioning). Injections of cAMP or PBS into L4, 5 DRGs was done 1 day after C3 lesions.