Ca2+-activated KCa3.1 potassium channels contribute to the slow afterhyperpolarization in L5 neocortical pyramidal neurons
| Autor: | Pavel M. Balaban, M. V. Roshchin, V. N. Ierusalimsky, E. S. Nikitin |
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| Rok vydání: | 2020 |
| Předmět: |
Male
0301 basic medicine Patch-Clamp Techniques lcsh:Medicine Action Potentials Neocortex Gating Ion channels in the nervous system Article 03 medical and health sciences 0302 clinical medicine Intrinsic excitability Cellular neuroscience medicine Animals Patch clamp Rats Wistar lcsh:Science CA1 Region Hippocampal Ions Microscopy Confocal Multidisciplinary Chemistry Pyramidal Cells lcsh:R Afterhyperpolarization Intermediate-Conductance Calcium-Activated Potassium Channels Axons Potassium channel Rats Perfusion Electrophysiology 030104 developmental biology medicine.anatomical_structure Microscopy Fluorescence Slow afterhyperpolarization lcsh:Q Calcium Female Neuroscience 030217 neurology & neurosurgery |
| Zdroj: | Scientific Reports Scientific Reports, Vol 10, Iss 1, Pp 1-10 (2020) |
| ISSN: | 2045-2322 |
| Popis: | Layer 5 neocortical pyramidal neurons are known to display slow Ca2+-dependent afterhyperpolarization (sAHP) after bursts of spikes, which is similar to the sAHP in CA1 hippocampal cells. However, the mechanisms of sAHP in the neocortex remain poorly understood. Here, we identified the Ca2+-gated potassium KCa3.1 channels as contributors to sAHP in ER81-positive neocortical pyramidal neurons. Moreover, our experiments strongly suggest that the relationship between sAHP and KCa3.1 channels in a feedback mechanism underlies the adaptation of the spiking frequency of layer 5 pyramidal neurons. We demonstrated the relationship between KCa3.1 channels and sAHP using several parallel methods: electrophysiology, pharmacology, immunohistochemistry, and photoactivatable probes. Our experiments demonstrated that ER81 immunofluorescence in layer 5 co-localized with KCa3.1 immunofluorescence in the soma. Targeted Ca2+ uncaging confirmed two major features of KCa3.1 channels: preferential somatodendritic localization and Ca2+-driven gating. In addition, both the sAHP and the slow Ca2+-induced hyperpolarizing current were sensitive to TRAM-34, a selective blocker of KCa3.1 channels. |
| Databáze: | OpenAIRE |
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