Lecture 11 – Van der Zee 7,8
Chapter 23 (14-817 (not the part about LTD); principles discuss here are similar for
cortex as hippocampus)
Chapter 24 (827-828, 847-852 (unti l hippocampal functi ons beyond spati al memory)
Chapter 25 (874-879, 886-887 related to fi gure 25.17)
Principles of place and grid cells provide us a glimpse of how the brain works.
John O’Keefe discovered in 1971 place cells in the hippocampus.
May-Britt Moser and Edvard I. Moser discovered in 2005 grid cells in the entorhinal cortex.
Place cells
The hippocampus is directly linked to the entorhinal cortex.
O’Keefe discovered by altering surrounding environment, that the animals wasn’t simply responding
to sensory cues. Rather, the neurons were responding to a more sophisticated sense of location.
A neuron starts firing when you are at a specific place:
For older rats it is harder to construct a spatial map
than it is for younger rats, as shown above.
However, some place cells follow local cues, some distal cues, and some are ambiguous. Confusion of
an animal about its location in an environment seen in behaviour is reflected in the behaviour of
place cells —> the confidence of where the animal is, is related to the firing of the place cells, the
more confident, the more similar is the firing of the place cells.
In 3D the field of the place cells are also in 3D; the same principles applies as found in 2D.
Grid cells
Moser and Moser thought that maybe hippocampal place cells are instructed by place cells
elsewhere.
Grid cells, together with other cells in the entorhinal cortex that recognize the direction of the head
of the animal and the border of the room, form networks with the place cells in the hippocampus.
This circuitry constitutes a comprehensive positioning system, an inner GPS in the brain. The
positioning system in the human brain appears to have similar components as those of the rat brain.
One place cell gets input from circa 100 grid cells.
A single grid cell fires when a rat crosses certain points on the floor; it turns out that these points
form a hexagonal grid, like a honeycomb. A hexagonal pattern gives the highest possible spatial
Chapter 23 (14-817 (not the part about LTD); principles discuss here are similar for
cortex as hippocampus)
Chapter 24 (827-828, 847-852 (unti l hippocampal functi ons beyond spati al memory)
Chapter 25 (874-879, 886-887 related to fi gure 25.17)
Principles of place and grid cells provide us a glimpse of how the brain works.
John O’Keefe discovered in 1971 place cells in the hippocampus.
May-Britt Moser and Edvard I. Moser discovered in 2005 grid cells in the entorhinal cortex.
Place cells
The hippocampus is directly linked to the entorhinal cortex.
O’Keefe discovered by altering surrounding environment, that the animals wasn’t simply responding
to sensory cues. Rather, the neurons were responding to a more sophisticated sense of location.
A neuron starts firing when you are at a specific place:
For older rats it is harder to construct a spatial map
than it is for younger rats, as shown above.
However, some place cells follow local cues, some distal cues, and some are ambiguous. Confusion of
an animal about its location in an environment seen in behaviour is reflected in the behaviour of
place cells —> the confidence of where the animal is, is related to the firing of the place cells, the
more confident, the more similar is the firing of the place cells.
In 3D the field of the place cells are also in 3D; the same principles applies as found in 2D.
Grid cells
Moser and Moser thought that maybe hippocampal place cells are instructed by place cells
elsewhere.
Grid cells, together with other cells in the entorhinal cortex that recognize the direction of the head
of the animal and the border of the room, form networks with the place cells in the hippocampus.
This circuitry constitutes a comprehensive positioning system, an inner GPS in the brain. The
positioning system in the human brain appears to have similar components as those of the rat brain.
One place cell gets input from circa 100 grid cells.
A single grid cell fires when a rat crosses certain points on the floor; it turns out that these points
form a hexagonal grid, like a honeycomb. A hexagonal pattern gives the highest possible spatial
