Anatomy of the temporal lobe: From macro to micro

Abstract

The temporal cortex encompasses a large number of different areas ranging from the six-layered isocortex to the allocortex. The areas support auditory, visual, and language processing, as well as emotions and memory. The primary auditory cortex is found at the Heschl gyri, which develop early in ontogeny with the Sylvian fissure, a deep and characteristic fissure that separates the temporal lobe from the parietal and frontal lobes. Gyri and sulci as well as brain areas vary between brains and between hemispheres, partly linked to the functional organization of language and lateralization. Interindividual variability in anatomy makes a direct comparison between different brains in structure-functional analysis often challenging, but can be addressed by applying cytoarchitectonic probability maps of the Julich-Brain atlas. We review the macroanatomy of the temporal lobe, its variability and asymmetry at the macro- and the microlevel, discuss the relationship to brain areas and their microstructure, and emphasize the advantage of a multimodal approach to address temporal lobe organization. We review recent data on combined cytoarchitectonic and molecular architectonic studies of temporal areas, and provide links to their function.

Keywords: Amygdala; Auditory; Cytoarchitecture; Hippocampus; Julich-Brain atlas; Macroanatomy; Receptor; Temporal cortices; Variability.