A method of HRP bathing of transected peripheral nerves using a rubber bag.--Its technique and advantage

The horseradish peroxidase (HRP) bathing method of transected peripheral nerves using a small rubber bag is described and its advantage for labeling neurons is evaluated. In order to apply the HRP to the peripheral nerves, a small rubber bag of appropriate size for the nerves to be bathed was made and was filled with a solution of 20% HRP. The proximal stump of the transected nerve was then inserted into the rubber bag. Nerve cell bodies, retrogradely labeled by this method, were observed to be intense. HRP diffusion to the surrounding tissues was considered negligible at the bathing region. The method presented in this paper is useful adjacent to methods previously reported for HRP application to the peripheral nerves. To illustrate this method, the results of the HRP bathing of either the chorda tympani or the intermediofacial nerve in cats were described.