Succinic dehydrogenase(SDH), acid phosphatase(ACP), adenosine triphosphatase(ATPase) and alkaline phosphatase(AKP) in sciatic nerve were stained with histochemistry to research the peripheral nerve changes and its pathogenesis associated with riboflavin deficiency in chicken. The results showed that the SDH activity decreased in Schwann cells and axons, but the ACP increased obviously, both the ATPase and AKP in Schwann cell membrane decreased. The changes of activity in SDH, ATPase and AKP were observed fo...