Parallel Computational Subunits in Dentate Granule Cells Generate Multiple Place Fields
Figure 7
Spatial firing patterns with different number of dendritic subunits.
(A) The number of dendritic place fields increases with the number of subunits although the probability of learning were kept constant. (B) The correlation between the somatic activity (as) and the maximal input (U*) decreases if the number of dendritic subunits increases. Open circles: correlation in the absence of dendritic spikes. Error bars on A and B show the standard deviation of 50 trials in 5 different environment. (C–D) Spatial firing patterns with N = 4 (C) and N = 100 (D) dendritic subunits. Upper and middle row is the same as on Figure 6. Lower row: scatter plot showing the joint distribution of the somatic activation as and the maximal dendritic input U*. Threshold for synaptic plasticity in the branches (horizontal line) and somatic firing (vertical line) are indicated. The correlation between the two variables is shown above the panels. If the neuron has a small number of dendritic subunits than the number of dendritic fields is small (A, C) but they propagate efficiently to the soma. Conversely, a neuron with a large number of dendritic subunits might have numerous dendritic fields, but the individual dendritic spikes have a little impact on the somatic activation.