[Neuronal organization of the plexus myentericus (Auerbach) in the small intestine of the pig. IV. Type IV-Neurons].

In extension of Dogiel's neuron-typification there is demonstrated a 4th neuron-population (type IV-cells) of the nervous system of the intestinal wall. The elements of this population are mainly characterized as follows: 1. They are polar (up to radiate) multidendritic uniaxonal neurons with extremely marginal nuclei. 2. The type IV-neurons are organized in modified aggregates topographically related to the communicating branches between the plexus myentericus (Auerbach) and the plexus submucosus externus (Schabadasch). 3. The neurits of type IV-cells run through the communicating branches to the plexus Schabadasch, thus forming typespecific vertical routes within the nervous system of the intestinal wall. The morphological findings are discussed in relation to the most recent electrophysiological, immunohistochemical and autoradiographic results of other authors.