Download Neuronal correlates of spatial memory

Neuronal correlates of spatial
memory
How do we remember where we
are?
How can I find my way back to my car?
The hippocampus and spatial memory
Higher grey matter density correlates
with time as a taxi driver
Maguire et al, 2000
Hippocampus
Formed of neurons
Neurons communicate via synapses : sending small electrical pulses
We can record the activity of single neurons in the hippocampus
Place cells
All place cells taken together form a cognitive map of the environment
O’Keefe and Nadel 1978,Moser et al, 2008
In human
Taxi video game
Some cells only fire at a given location in the virtual environment
 Human place cells
Ekstrom et al, 2003
What determines the place field of a
place cell?
Stretchy place fields
Place fields appear to
respond at fixed
distances from walls,
with nearer walls
more important than
further ones.
Boundary place fields
Place fields appear to
respond to a boundary
in a given orientation
in the environment.
Barry et al, 2006
In human
Doeller et al, 2008
Path integration
Animals are able to find their way back even in total darkness
How does the brain compute the straight way back?
Head direction cells
Head direction cells give information about the direction the animal
is facing
Taube et al, 1990
Grid cells
All grid cells taken together allow the animal to compute path
integration
Hafting et al, 2005
In human
Enthorhinal cortex
Doeller et al, 2010
How will I get back then?
-Distant boundaries: Place cells
-Compute the straight way back:
-Head direction cells
-Grid cells
-Reconstruct the place where the car should be: Visual imagery