Structure: < Click on image >

Types of Cerebral Cortex, Cell Stains. Four radial sections through different cortical areas have been stained to reveal cell bodies. Different patterns of cell body lamination and densities (cytoarchitecture) identify different regions. (A) Neocortex of the occipital lobe. Neocortex is phylogenetically the newest type of cortex, and is characterized by the presence of six cell layers at least at some point in development. Note the primary visual cortex (a) to the left of the line. It stands out from the adjacent neocortex (b--secondary or association visual cortex) in part because layer 4, the layer that receives thalamic input, is subdivided in primary visual cortex. (B) Another example of sensory (somatosensory) neocortex. Can you convince yourself that there are six layers? (C) and (D) both show examples of "older" cortical types, and transitional types between those and neocortex. (C) The complex hippocampal formation (a), is seen to the right of the line. It is an example of archicortex, which has three layers. Between the archicortex (a) and the neocortex (b) is a transitional cortical region with a variety of cell clumps that at this level forms the entorhinal cortex of the parahippocampal gyrus (see Limbic System chapter). (D) The piriform cortex (a), another older type of cortex (paleocortex--also 3-layered), is adjacent to the amygdala. There is a transitional region between it and the neocortex (b).

Quizzes (these require Java Web Start):

Software (C) 1997 <---> Images (C) 2000