Redox Sensitive Calcium Stores Underlie Enhanced After Hyperpolarization of Aged Neurons: Role for Ryanodine Receptor Mediated Calcium Signaling

• DOI: 10.1152/jn.00577.2010
• Publication Date: 2010-09-09T02:21:02Z
• Authors: Karthik Bodhinathan; Ashok Kumar; Thomas C. Foster
• Keywords: Thapsigargin; Dithiothreitol; Hyperpolarization; Iberiotoxin

A decrease in the excitability of CA1 pyramidal neurons contributes to age related hippocampal function and memory decline. Decreased neuronal aged can be observed as an increase Ca(2+)- activated K(+)- mediated post burst afterhyperpolarization (AHP). In this study, we demonstrate that slow component AHP (sAHP) (aged-sAHP) is decreased ∼50% by application reducing agent dithiothreitol (DTT). The DTT-mediated sAHP was specific, such it (20-25 mo), but not young (6-9 mo) F344 rats. effect DTT on aged-sAHP blocked following depletion intracellular Ca(2+) stores (ICS) thapsigargin or blockade ryanodine receptors (RyRs) ryanodine, suggesting age-related due release from ICS through redox sensitive RyRs. inhibition L-type voltage gated channels (L-type VGCC), Ser/Thr kinases, large conductance BK potassium channels. results add support idea a shift state dysregulation during aging.