Cortical area · one in each half of the brain
Entorhinal cortex
Also called EC, Brodmann area 28
The hippocampus's front door, and home of the brain's built-in grid map.
The entorhinal cortex is the main gateway between the hippocampus and the rest of the cortex. Most information the hippocampus learns arrives through it, and memories head back out through it too. It contains grid cells, which fire in a repeating triangle pattern as you move, forming a built-in coordinate system. It is also one of the very first places harmed in Alzheimer's disease.
Where it is
Deep inside, at the front of the inner temporal lobe, on the front part of the parahippocampal gyrus, right next to the front of the hippocampus.
What it does
Gateway to the hippocampus
It gathers input from all over the cortex and sends it into the hippocampus through a pathway called the perforant path.
Grid cells
Its grid cells fire at evenly spaced spots as you move, like points on a triangular grid, telling you how far and which way you have gone.
Sense of direction
Other cells here track which way your head is facing and where the edges of a room are.
Storing memories long term
It helps pass memories from the hippocampus back out to the cortex for long-term keeping.
Think of it as graph paper that your brain lays over every place you walk through, plus the front door to your memory archive.
Works with
- HippocampusIts main partner. It feeds the hippocampus nearly everything it needs to build new memories.
- Dentate gyrusIts fibers reach the dentate gyrus first, the entry point of the hippocampus.
- SubiculumThe subiculum, the hippocampus's main exit, sends its output back to this area, closing the loop.
- Parahippocampal gyrusThis neighbor sends it information about scenes and places.
- Olfactory nerve & bulb (I)Smell signals reach it with very few stops, which may be one reason smells can trigger vivid memories.
When it goes wrong
Alzheimer's disease
Tangles of a protein called tau often build up here early, years before symptoms. That can disrupt the hippocampus's link with the rest of the cortex, making new memories hard to form.
Getting lost
Trouble finding your way, even in familiar places, can be an early sign of Alzheimer's disease, possibly because grid cells stop working properly.
For learning only, not medical advice. If you have a health concern, talk to a doctor.
Surprising facts
- Grid cells were discovered in rats in 2005 by Norwegian scientists May-Britt Moser and Edvard Moser. They shared the 2014 Nobel Prize with John O'Keefe, who had discovered "place cells" in the hippocampus.
- Brain scans suggest humans have grid-like signals too, even when just imagining walking through a place.
- The grid pattern is made of triangles, so together the firing spots form hexagons, like a honeycomb laid over the room.
By the numbers
Where the name comes from
From the Greek "entos" (inside) and "rhis, rhinos" (nose). It lies by the rhinal sulcus, a groove named after the nose that separates it from the brain's smell cortex.
Learn it in a lesson
- The hidden cortexInsula, cingulate and the inner surfaces. A short guided lesson in 3D.
- MemoryThe hippocampus and its circuit. A short guided lesson in 3D.
Quick quiz
3 questions. Your answers are saved and come back in your daily review.
Which of these is a job of the entorhinal cortex?
Show the answer
Gateway to the hippocampus. It gathers input from all over the cortex and sends it into the hippocampus through a pathway called the perforant path.
Gateway to the hippocampus. It gathers input from all over the cortex and sends it into the hippocampus through a pathway called the perforant path.
The entorhinal cortex is part of which larger structure?
Show the answer
Medial temporal cortex. It belongs to the medial temporal cortex.
Medial temporal cortex. It belongs to the medial temporal cortex.
Which part fits this description? "Like graph paper that your brain lays over every place you walk through, plus the front door to your memory archive."
Show the answer
Entorhinal cortex. It is the entorhinal cortex. The hippocampus's front door, and home of the brain's built-in grid map.
Entorhinal cortex. It is the entorhinal cortex. The hippocampus's front door, and home of the brain's built-in grid map.
These parts now come back in your daily review, just before you would forget them.
Practice it and its neighbors in 3DSources
- Explicit Memories: Episodic and Semantic Memories, OpenStax, Introduction to Behavioral Neuroscience
- Entorhinal cortex, Radiopaedia
- Alzheimer Disease, StatPearls, NCBI Bookshelf
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Explore the entorhinal cortex in 3D
Turn it around, zoom inside and see how it connects to the rest of the brain, then test yourself with quick quizzes.
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