Since we introduced cultured dorsal root ganglia (DRG) neurons from streptozotocin (STZ)-induced diabetic mice as "an in vitro model to study diabetic neuropathy" (Sotelo et al., 1991), more than 30 papers have been devoted to the study of diabetic neuropathy with culture systems of neurons and Schwann cells derived from adult animals. So far, methods for dissociated cell culture of peripheral neurons (mainly DRG neurons) and Schwann cells, and for explant culture of peripheral ganglia and retinas have been applied to diabetic animals or patients. In addition to these diabetic cells, adult animal neurons and Schwann cells cultured under high glucose conditions and adult animal neurons exposed to diabetic serum have been utilized. The findings from these culture models clearly show that the exposure of mature neurons and Schwann cells to hyperglycemic conditions in vivo or in vitro can alter their biophysical and biochemical properties (e.g., cell viability, neurite outgrowth activity, polyol metabolism and electrophysiological features). Therefore, the cultured neurons and Schwann cells can be useful tools for investigating the precise mechanisms leading to diabetic neuropathy and the efficacy of therapeutic agents for the prevention and treatment of that condition.