Diabetes mellitus-induced hyperglycemia is associated with a number of pathologies such as retinopathy, nephropathy, delayed wound healing, and diabetic peripheral neuropathy (DPN). Approximately 50% of patients with diabetes mellitus will develop DPN, which is characterized by disrupted sensory and/or motor functioning, with treatment limited to pain management. Zebrafish (Danio rerio) are an emerging animal model used to study a number of metabolic disorders, including diabetes. Diabetic retinopathy, nephropathy, and delayed wound healing have all been demonstrated in zebrafish. Recently, our laboratory has demonstrated that following the ablation of the insulin-producing β-cells of the pancreas (and subsequent hyperglycemia), the peripheral nerves begin to show signs of dysregulation. In this study, we take a different approach, taking advantage of the transdermal absorption abilities of zebrafish larvae to extend the period of hyperglycemia. Following 5 days of 60 mM d-glucose treatment, we observed motor axon defasciculation, disturbances in perineurial glia sheath formation, decreased myelination of motor axons, and sensory neuron mislocalization. This study extends our understanding of the structural changes of the peripheral nerve following induction of hyperglycemia and does so in an animal model capable of potential DPN drug discovery in the future.NEW & NOTEWORTHY Zebrafish are emerging as a robust model system for the study of diabetic complications such as retinopathy, nephropathy, and impaired wound healing. We present a novel model of diabetic peripheral neuropathy in zebrafish in which the integrity of the peripheral nerve is dysregulated following the induction of hyperglycemia. By using this model, future studies can focus on elucidating the underlying molecular mechanisms currently unknown.
Keywords: hyperglycemia; motor nerve; myelination; perineurial glia; perineurium; sensory neurons.