Local changes in potassium ions regulate input integration in active dendrites.
During neuronal activity, the extracellular concentration of potassium ions ([K+]o) increases substantially above resting levels, yet it remains unclear what role these [K+]o changes play in the dendritic integration of synaptic inputs. We here used mathematical formulations and biophysical modeling...
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Main Authors: | , , , , , |
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Format: | Article |
Language: | English |
Published: |
Public Library of Science (PLoS)
2024-12-01
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Series: | PLoS Biology |
Online Access: | https://doi.org/10.1371/journal.pbio.3002935 |
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Summary: | During neuronal activity, the extracellular concentration of potassium ions ([K+]o) increases substantially above resting levels, yet it remains unclear what role these [K+]o changes play in the dendritic integration of synaptic inputs. We here used mathematical formulations and biophysical modeling to explore the role of synaptic activity-dependent K+ changes in dendritic segments of a visual cortex pyramidal neuron, receiving inputs tuned to stimulus orientation. We found that the spatial arrangement of inputs dictates the magnitude of [K+]o changes in the dendrites: Dendritic segments receiving similarly tuned inputs can attain substantially higher [K+]o increases than segments receiving diversely tuned inputs. These [K+]o elevations in turn increase dendritic excitability, leading to more robust and prolonged dendritic spikes. Ultimately, these local effects amplify the gain of neuronal input-output transformations, causing higher orientation-tuned somatic firing rates without compromising orientation selectivity. Our results suggest that local, activity-dependent [K+]o changes in dendrites may act as a "volume knob" that determines the impact of synaptic inputs on feature-tuned neuronal firing. |
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ISSN: | 1544-9173 1545-7885 |