Conduction failure of action potentials in sensory sural nerves of undernourished rats

In order to determine possible functional and morphometrical alterations produced by perinatal undernourishment on peripheral nerves, sensory sural nerves from control and undernourished rats of 30 and 90 postnatal days of age were dissected and divided in two segments, one for recording the compound action potential (CAP) and the other for histological examination. Nerves from undernourished animals showed maximal CAP responses of smaller amplitude and area, larger trial-to-trial variability in area, and a significant reduction in axonal myelin sheath thickness than nerves from control animals. It is suggested that perinatal undernourishment produces changes in axonal myelin sheath structure, resulting in severe alterations in the generation and propagation of action potentials (block and/or intermittent conduction) in sensory afferent fibers in the rat.