Splitters

Some place cells in the hippocampus fire in a conditional way.   For example, a place cell might fire at the beginning of the maze, but only when the animal is on its way to a specific destination, as shown in the figure below.  We’ve referred to such cells as ‘splitters’  because their firing is unequally split between different traversals of the same location. The modulation of place cell activity by the anticipated destination of the rat may reflect a basic example of how the hippocampus participates in the representation of imagined experiences.

place cell splitter

Example of a place cell that fires when the rat runs to the left-most destination, but that shows little firing when the rat runs to the other three destinations. Red dots represent individual spikes of a place cell. The black lines are the traces of the animal's path. The left plot shows the firing of the neuron for the entire session. The middle plot shows this same activity, but separated based on the destination the rat choose. The right graph shows the difference in this place cell's firing for the four different destinations.