Dramatically Amplified Thoracic Sympathetic Postganglionic Excitability and Integrative Capacity Revealed with Whole-Cell Patch-Clamp Recordings
| Autor: | Yaqing Li, Alan J. Sokoloff, Astrid A. Prinz, Shawn Hochman, Kun Tian, Mi Hyun Choi, Meredith Lucy Galvin, Michael L. McKinnon |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Male
Sympathetic nervous system Patch-Clamp Techniques Sympathetic Nervous System Models Neurological Membrane Potentials Mice 03 medical and health sciences Sympathetic Fibers Postganglionic 0302 clinical medicine medicine Animals Patch clamp 030304 developmental biology 0303 health sciences Erratum/Corrigendum Chemistry General Neuroscience Time constant General Medicine Paravertebral ganglia Mice Inbred C57BL Electrophysiology Microelectrode medicine.anatomical_structure Female Whole cell Neuroscience 030217 neurology & neurosurgery Vasomotor tone |
| Zdroj: | eneuro. 6:ENEURO.0433-18.2019 |
| ISSN: | 2373-2822 |
| DOI: | 10.1523/eneuro.0433-18.2019 |
| Popis: | Thoracic paravertebral sympathetic postganglionic neurons (tSPNs) comprise the final integrative output of the distributed sympathetic nervous system controlling vascular and thermoregulatory systems. Considered a non-integrating relay, what little is known of tSPN intrinsic excitability has been determined by sharp microelectrodes with presumed impalement injury. We thus undertook the first electrophysiological characterization of tSPN cellular properties using whole-cell recordings and coupled results with a conductance-based model to explore the principles governing their excitability in adult mice of both sexes. Recorded membrane resistance and time constant values were an order of magnitude greater than values previously obtained, leading to a demonstrable capacity for synaptic integration in driving recruitment. Variation in membrane resistivity was the primary determinant controlling cell excitability with vastly lower currents required for tSPN recruitment. Unlike previous microelectrode recordings in mouse which observed inability to sustain firing, all tSPNs were capable of repetitive firing. Computational modeling demonstrated that observed differences are explained by introduction of a microelectrode impalement injury conductance. Overall, tSPNs largely linearly encoded injected current magnitudes over a broad frequency range with distinct subpopulations differentiable based on repetitive firing signatures. Thus, whole-cell recordings reveal tSPNs have more dramatically amplified excitability than previously thought, with greater intrinsic capacity for synaptic integration and with the ability for maintained firing to support sustained actions on vasomotor tone and thermoregulatory function. Rather than acting as a relay, these studies support a more responsive role and possible intrinsic capacity for tSPNs to drive sympathetic autonomic function. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|