The entorhinal cortex is in the medial temporal lobe, on the inner underside of each temporal lobe: it is the front (rostral) part of the parahippocampal gyrus, next to the hippocampus, roughly Brodmann areas 28 and 34. [1][2]
The 3D brain needs JavaScript. The text below still says where the entorhinal cortex is and what it does.
Opens cut by a front (coronal) slice through the parahippocampal gyrus, which holds the entorhinal cortex. Drag to turn, pinch or scroll to zoom, tap any part to name it; .
Lit: the whole parahippocampal gyrus, on both sides. The area is part of this gyrus; its exact border is not drawn. The entorhinal cortex is a portion of the rostral (front) parahippocampal gyrus. The model draws the parahippocampal gyrus as one shape, so the whole gyrus is lit. [1][3][4]
Takes part in: memory, navigation — see every part of each lit together.
Where it is
It is an area of the allocortex in the medial temporal lobe. [1]
It is a portion of the rostral (front) parahippocampal gyrus. [1]
The front part of the parahippocampal gyrus includes the entorhinal and perirhinal cortices. [3]
Brodmann area 28 lies on the medial aspect of the temporal lobe, adjacent to the hippocampus; together with area 34 it makes up approximately the entorhinal cortex. [2]
It is usually divided into medial and lateral regions, and it has no cell bodies where layer IV should be: a cell-free band called the lamina dissecans. [1]
What it does
It is the main interface between the hippocampus and the neocortex, and a widespread network hub for memory, navigation and the perception of time. [1]
With the hippocampus it plays an important role in declarative memories (autobiographical, episodic and semantic), in particular spatial memories, including forming, consolidating and optimising them in sleep. [1]
Grid cells: in rats, neurons of the medial entorhinal cortex fire at many places arranged in a hexagonal pattern, a map of the surroundings discovered in 2005 and part of the 2014 Nobel Prize to John O’Keefe, May-Britt Moser and Edvard Moser; grid-like signals were later seen in humans with fMRI while they navigated a virtual space. [1]
The rat medial entorhinal cortex also holds speed cells, whose firing rate tracks how fast the animal moves. [1]
Connections
Its layer II projects mainly to the dentate gyrus and region CA3 of the hippocampus, its layer III mainly to region CA1 and the subiculum. [1]
Those layers take in input from other cortical areas, especially the perirhinal and parahippocampal cortices and the prefrontal cortex, so it receives highly processed input from every sense. [1]
Its deep layers, especially layer V, receive one of the three main outputs of the hippocampus. [1]
The olfactory tract carries smell signals to targets including the piriform cortex, the amygdala and the entorhinal cortex. [5]
Other names
Entorhinal cortex, EC. Brodmann area 28 is the “area entorhinalis” and area 34 the “area entorhinalis dorsalis”. [1]
In humans, Brodmann areas 28 and 34 together make up approximately the entorhinal cortex. [2]
Size
The model has no shape for the entorhinal cortex itself, so it is not measured here. The whole left parahippocampal gyrus that holds it measures about 49 mm front to back, 22 mm top to bottom and 21 mm side to side on this model (the box it fits in, not its volume). [4]
Facts describe anatomy and normal function only. The 3D model is the adult male BodyParts3D brain (credits and licence); real brains vary in size and shape, so its measurements describe one model, not anyone’s brain.