Cerebral Cortex

Detail from a vertical section of the is cortex with internal pyramidal layer  ( lamina pyramidalis interna or ganglionaris), layer V, and the internal granular layer (lamina granularis interna ), layer VI. The pyramidal cells reach a height of 120 μm and a width of 80 μm. The cell bodies 1 are stained brown in this preparation. Pyramidal cells send out long ascending dendrites 2 .A strong axon extends from the basal cytoplasm of the pyramidal cells. The axons of these Betz giant cells are part of the pyramidal tract .

1 Cell bodies of pyramidal cells

2 Dendrites

Stain: Bielschowsky -Gros silver impregnation; magnification: × 300

Cerebral Cortex

Section of the isocortex, primary motor cortex, area 4 (precentral gyrus, Brodmann’s area 4).  Pyramidal cells of the internal pyramidal cell layer (layer V) are stained using Golgi’s silver impregnation technique. The cell bodies and all cell processes of the nerve cells are stained.  Pyramidal cells are type 1 Golgi cells. Axons, which end in extracortical tissue, are one of their characteristic features. The cell bodies of the pyramidal cells have diameters between 10 and 70 μm. The largest pyramidal cells are the Betz giant cells and the Meynert cells. The pyramidal cell owes its name to the roughly triangular faces of its cell body. The basis of the pyramid usually points toward the medulla. The branching apical dendrites run from the tip of the pyramid to the cortical surface. There are also dendrites at the basal plasma membrane. These run pre dominantly in a horizontal direction. The axon exits the pyramidal cell at the basal axon hillock and extends toward the medulla. Apical and basal dendrites are densely covered with spikes. Collaterals split from the axon shortly after it exits the pyramidal cell at the axon hillock . The collaterals either ascend or run in horizontal direction.

Stain: Golgi silver impregnation; magnification: × 500

References

Kuehnel, W.(2003). Color Atlas of Cytology, Histology, and Microscopic Anatomy. 4^th edition . Institute of Anatomy Universitätzu Luebeck Luebeck, Germany . Thieme Stuttgar t · New York .