structured_inhibition_spatial_network_model

Functional aspects of interneuron morphology in the subiculum

Interneurons in the subiculum have a polar axonal cloud instead of a circular as found in other brain regions. Additionally, pyramidal neurons in the subiculum lack recurrent connections, but they connect via recurrent inhibition. Therefore, inhibition plays a major role in this circuitry and we pose the question, which function the extraordinary axon morphology serves in this setting.

Model

1. Distribute excitatory somata in space.
2. Distribute inhibitory somata in space.
3. Choose an axonal shape (polar or circular).
4. Connect excitatory neurons which are contained the same interneuron axonal cloud.

Analysis

1. Compare first and second order connectivity

Two neurons directly connected neuron inhibit each other, because they project to the same interneuron (as a circuit motif E<->I<->E). Therefore, second order neighbors are effectively excitatory (via disinhibition). We therefore extracted the distance dependent first and second order connectivity to compare them for polar and circular axonal shapes.