Figure 5.

The Oblique Integration Test evaluated nonlinear dendritic integration of asynchronous and synchronous synaptic inputs in the oblique dendrites of the tested models. (a) The mean threshold for dendritic spike initiation, the proximal threshold for dendritic spike initiation, and the distal threshold for dendritic spike initiation, and the amplitude at the threshold measured at the soma with a dendritic spike present. (b) The increase in the somatic voltage upon a dendritic spike can be characterized by the time in which the maximum amplitude is reached (time to peak). All models had this value significantly lower than experimental data. (c) The mean threshold nonlinearity associated with a dendritic spike, suprathreshold nonlinearity and the degree of nonlinearity for asynchronous input patterns calculated for each tested model. (d) The peak temporal derivative of somatic voltage response at the threshold for dendritic spike initiation. (e) Averaged input – output curves for synchronous inputs of all tested models. A sharp increase in the curve indicates a dendritic spike. Dashed line represents linear summation. (f) Plot of dV/dt versus number of inputs. Arrows indicate the number of synchronous inputs required to induce a dendritic spike. Note a sharp increase in the somatic voltage during the dendritic spike initiation. All experimental values with the double standard deviations were obtained from the paper of Losonczy and Magee³¹.