CoursesHistologyBody systemsNervous systemCerebral cortex

Cerebral cortex

Learning objectives

After completing this study unit you will be able to:

Understand the structure of the cerebral cortex and name the layers of the isocortex.
Explain the types of nerve cells found in the cerebral cortex.

Browse atlas

The cerebral cortex comprises the outer layer of the cerebrum and is mainly made up of gray matter. This region of the brain is responsible for numerous higher cognitive functions, including memory, attention, perception and consciousness. The cerebral cortex consists of the evolutionary older allocortex and the younger isocortex, which represents the majority of the cortex. The allocortex consists of 3 - 4 layers and the isocortex consists of 6 layers.

Each of the six layers (horizontal laminae) of the isocortex has a unique cell population and function. The layers are, from superficial to deep, the molecular layer, the external granular layer, the external pyramidal layer, the internal granular layer, the internal pyramidal layer and the multiform layer. This classification is based primarily on the cellular structures and density of nerve cells.

Neurons are the dominant cells in the cortex and can be divided into two main types, pyramidal cells and nonpyramidal cells (interneurons). While pyramidal cells are primarily excitatory and use glutamate as a neurotransmitter, most nonpyramidal cells are inhibitory and release GABA. These neurons are interconnected and form a complex network of synapses through which information is processed and transmitted.