The cerebral cortex is the largest of the brain regions, and is divided into two hemispheres, and is in charge of higher cognitive function such as decision making, thoughts and behavior. The cerebral cortex is folded to provide a larger surface area and the ridges of the folds are called gyrus and the groves are called sulcus.
Primary function of the cerebral cortex is to handle information, processing sensory input from other regions of the central nervous system and controlling voluntary motor output. The cerebral cortex acts as a relay station where it selects and sorts information and sends it back to thalamus subcortical regions where the response is happening in the form of behavior and movement.
The main neuronal cell type in the cerebral cortex are glutamatergic pyramidal neurons and inhibitory (mainly GABA-ergic) interneurons. These cells are organized in six cellular layers, in the gray matter, based on cell densities, morphology electrophysiological properties and connections. The cerebral cortex receives its main excitatory input from the thalamus. The white matter, approximately 40% of the cerebral cortex, contains the myelinated input axons originating from subcortical structures and myelinated axons originating from cortical pyramidal neurons projecting to subcortical areas of the brain.