The 245 chemical synapses ( N s y n = 245 ) which were randomly dispersed across the basal dendrites received synchronous inputs. (F–J) Same as panels (A–E) but for active dendritic structures receiving synchronous inputs through dendro-dendritic gap junctions ( N j u n = 99 ). The four different model configurations shown are the default active model, and the active models where sodium channels, leak channels, or both sodium and leak channels were absent. While outward HCN currents (Figure 3B) are also expected to influence LFPs under chemical synaptic input, their impact was minimal due to the predominance of large inward synaptic currents (Figure 3A). Whereas leak channels played minimal roles in shaping extracellular potentials when inputs arrived through chemical synapses, they played a prominent role in defining extracellular potentials when inputs arrived through gap junctions.