A method for the demonstration of adrenergic nerve fibres in peripheral nerves

Summary The adrenergic nerve fibres running from the ganglia to the innervated tissues usually have too low a content of noradrenaline to be clearly visualized with the histochemical fluorescence method of Falck and Hillarp. They can easily be demonstrated, however, as early as 24 hours after axotomy (crushing or constriction of the nerves) due to the rapid accumulation of what is probably noradrenaline taking place proximally to the lesion. The fibres can be visualized even more clearly if axotomy is combined with the administration of l-dopa and with monoamine oxidase inhibition. In this way the presence, distribution and direction of adrenergic fibres can be directly studied in peripheral nerves.For generous supplies of drugs we are indepted to Swedish Ciba, Stockholm (reserpine) and Swedish Pfizer, Stockholm (nialamide). The investigation has been supported by research grants from the United States Public Health Service (NB 02854-04), the Swedish Medical Research Council, and Knut and Alice Wallenbergs Foundation.