these observations suggested that ( i ) some ntfs may be present in normal nerves and others may be synthesized or accumulated in response to nerve injury , ( ii ) sensory , sympathetic , and spinal cord ntfs are separate agents and immunochemically distinct from nerve growth factor , ( iii ) ntfs predominantly originate from nerve stumps rather than from surrounding fluid , and ( iv ) proximal and distal nerve stumps accumulate and release ntfs at similar rates .
C0027752
nerve growth
C0027754
ntfs