[The cytoarchitecture of the rat globus pallidus]

The globus pallidus of the adult rat was investigated by means of the Golgi-rapid-impregnation technique. The cellular population of the globus pallidus is composed of 4 morphologically different neuron types: 1. Large-sized, spindle-shaped neurons; 2. Large-sized, polygonal neurons; 3. Small spindle-shaped neurons; 4. Small spine-bearing neurons. The large spindle-shaped neurons and the large polygonal neurons are considered to be efferent pallidal neurons; the small spindle-shaped neurons and the small spiny neurons are suggested to be pallidal interneurons. It is possible to adapt the neuron classification presented here to recent imaginations concerning the role of the globus pallidus within the extrapyramidal system.