Figure 8.

Short-term changes in spike probability for neurons that are not monosynaptically connected. A, In a simulated circuit, we generated a spurious connection between two neurons (Post₁ and Post₂) receiving common excitatory drive from a single presynaptic neuron (Pre) with different delays (orange cross-correlogram). B, Scatter plots show normalized spike transmission probabilities from different sets of simulations where the true connections to the postsynaptic neurons have different types of STP (both depressing, both facilitating, and one depressing; one facilitating). Lines with same colors as scatter plots show the estimated spike probability from the TM-GLM. Here, the data and model fits are averaged across 150 rounds of simulations (50 for each combination) and are normalized to have a spiking probability of 1 for the longest ISIs. C, We then fit spike transmission probability for 38 pairs of neurons from the MEA recording where there was no clear monosynaptic connection (putative non-connections). Observed (left) spike transmission probabilities show relatively little variation as a function of one neuron's ISIs, but the TM-GLM (right) does describe what variation there is. Insets show example cross-correlograms from two of these putative non-connections.