• The most superficial layer is referred to as the molecular layer or stratum moleculare. It lies closest to the hippocampal fissure. Because of the connectional inputs from the entorhinal cortex, this layer is often subdivided in three: the outer, middle and inner part.
• The granule cell layer or stratum granulosum forms the principle cell layer of the DG. Typically, it is divided in three sections. Adjacent to CA1 lies the section called enclosed blade (or suprapyramidal blade/limb). The opposite section is called free/exposed blade (or infrapyramidal blade/limb). The section where the two blades connect is called the crest.
• The polymorphic layer or stratum multiforme is sometimes referred to as CA4 (suggested by Lorente de No, 1934), but in a calbindin staining the polymorphic layer and proximal part of CA3 can easily be distinguished. The polymorphic layer is often referred to as hilus.

In-between the granule cell layer and the polymorphic layer lies a narrow strip of cells that is termed the subgranular zone. The cells in the subgranular zone are linked to adult neurogenesis. See: Steven A Goldman & Zhuoxun Chen, 2011