Dynamics of Δ<i>E</i><sub>K</sub><sup>+</sup> \\with varying stimulus orientation.

<p>(a) Top: Example Δ<i>E</i><sub>K</sub><sup>+</sup> traces over time for a stimulus presented at the target orientation, arbitrary set at 0°. Solid lines show the evolution of Δ<i>E</i><sub>K</sub><sup>+</sup> of each dendritic segment along the dendrite (different colors), with the central dendritic segment, receiving similarly tuned synapses, being the reference point (distance = 0 μm, light orange). Dotted green line shows Δ<i>E</i><sub>K</sub><sup>+</sup> over time of a dendrite receiving exclusively diversely tuned input. After synaptic activation, the peak Δ<i>E</i><sub>K</sub><sup>+</sup> is reached within 150–200 ms. As also shown in <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.3002935#pbio.3002935.g001" target="_blank">Fig 1</a>, the largest shift in <i>E</i><sub>K</sub><sup>+</sup> is seen for the segment receiving similarly tuned synapses. Neighboring segments, receiving diversely tuned synapses, display a gradually decreasing shift, and for dendritic segments in distance, >40 μm, the Δ<i>E</i><sub>K</sub><sup>+</sup> is similar to the one expected from a dendrite receiving exclusively diversely tuned synapses (dotted green line). Middle, bottom: Δ<i>E</i><sub>K</sub><sup>+</sup> as function of stimulus orientation (22.5° and 45°, respectively). For a stimulus orientation far from target orientation, the shift in the <i>E</i><sub>K</sub><sup>+</sup> becomes smaller and similar to the diverse input tuning regime, as per <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.3002935#pbio.3002935.g001" target="_blank">Fig 1G and 1H</a>. Overall, for the diversely tuned segments the smooth Δ<i>E</i><sub>K</sub><sup>+</sup> is as a result well-mixed and uniform [K<sup>+</sup>]<sub>o</sub> throughout the outer cylinder. For the similarly tuned segment, an initial drop before stabilizing in Δ<i>E</i><sub>K</sub><sup>+</sup> is due to the concentration gradients with its adjacent segments, still maintaining higher Δ<i>E</i><sub>K</sub><sup>+</sup> levels when compared to diversely tuned segments. (b) Same data as above, for Δ[K<sup>+</sup>]<sub>o</sub>. Δ[K<sup>+</sup>]<sub>o</sub> lies within the interval [1:5 mM], as per <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.3002935#pbio.3002935.g001" target="_blank">Fig 1</a>, and follows the similar trend to the Δ<i>E</i><sub>K</sub><sup>+</sup>. For all plots, bottom rows indicate the activation timings of individual synapses.</p> <p>(PDF)</p>