Chapter II Neurochemical organization of the primate visual cortex

This chapter discusses the neurochemical organization of the primate visual cortex. Morphology is the primary determinant of the cell type in the cerebral cortex and is the principal basis for distinguishing fundamental classes of neocortical neurons. Connectivity, intrinsic biophysical membrane properties, and neurochemical features are also some of the distinguishing characteristics of the cell type. Visual information processing in the neocortex involves both localized functional specializations and distributed processing that simultaneously involves multiple regions. Information processing in the monkey visual system is distributed along well defined sets of connections linking the primary to secondary visual cortex, and from there to higher level association cortical areas located in the occipital, parietal, and temporal lobes. Primate visual cortex is composed of two fundamental classes of neurons: those that bear dendritic spines (spiny neurons), and those that are completely or mostly aspiny. Pyramidal cells are the major output neuron type of the cerebral cortex, with most of them supplying a principal axon that leaves the immediate cortical area to terminate in other cortical or subcortical regions.