Specificity in the Interaction of HVA Ca2+ Channel Types With Ca2+-Dependent AHPs and Firing Behavior in Neocortical Pyramidal Neurons

Juan Carlos Pineda , Robert S. Waters , and Robert C. Foehring Department of Anatomy and Neurobiology, University of Tennessee, Memphis, Tennessee 38163 Pineda, Juan Carlos, Roberts S. Waters, and Robert C. Foehring. Specificity in the interaction of HVA Ca 2+ channel types with Ca 2+ -dependent AHP...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Journal of neurophysiology 1998-05, Vol.79 (5), p.2522
Hauptverfasser: Pineda, Juan Carlos, Waters, Robert S, Foehring, Robert C
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:Juan Carlos Pineda , Robert S. Waters , and Robert C. Foehring Department of Anatomy and Neurobiology, University of Tennessee, Memphis, Tennessee 38163 Pineda, Juan Carlos, Roberts S. Waters, and Robert C. Foehring. Specificity in the interaction of HVA Ca 2+ channel types with Ca 2+ -dependent AHPs and firing behavior in neocortical pyramidal neurons. J. Neurophysiol. 79: 2522-2534, 1998. Intracellular recordings and organic and inorganic Ca 2+ channel blockers were used in a neocortical brain slice preparation to test whether high-voltage-activated (HVA) Ca 2+ channels are differentially coupled to Ca 2+ -dependent afterhyperpolarizations (AHPs) in sensorimotor neocortical pyramidal neurons. For the most part, spike repolarization was not Ca 2+ dependent in these cells, although the final phase of repolarization (after the fast AHP) was sensitive to block of N-type current. Between 30 and 60% of the medium afterhyperpolarization (mAHP) and between ~80 and 90% of the slow AHP (sAHP) were Ca 2+ dependent. Based on the effects of specific organic Ca 2+ channel blockers (dihydropyridines, -conotoxin GVIA, -agatoxin IVA, and -conotoxin MVIIC), the sAHP is coupled to N-, P-, and Q-type currents. P-type currents were coupled to the mAHP. L-type current was not involved in the generation of either AHP but (with other HVA currents) contributes to the inward currents that regulate interspike intervals during repetitive firing. These data suggest different functional consequences for modulation of Ca 2+ current subtypes.
ISSN:0022-3077
1522-1598
DOI:10.1152/jn.1998.79.5.2522