title: Imbalanced K+ and Ca2+ subthreshold interactions contribute to increased hypothalamic presympathetic neuronal excitability in hypertensive rats.
abstract: Despite the importance of brain-mediated sympathetic activation in the morbidity and mortality of patients with high blood pressure, the precise cellular mechanisms involved remain largely unknown. We show that an imbalanced interaction between two opposing currents mediated by potassium (I(A)) and calcium (I(T)) channels occurs in sympathetic-related hypothalamic neurons in hypertensive rats. We show that this imbalance contributes to enhanced membrane excitability and firing activity in this neuronal population. Knowledge of how these opposing ion channels interact in normal and disease states increases our understanding of underlying brain mechanisms contributing to the high blood pressure condition.
authors.affiliation: Department of Physiology, Medical College of Georgia, Augusta, GA 30912, USA.
authors.forename: P M
authors.initials: PM
authors.lastname: Sonner
authors.forename: S
authors.initials: S
authors.lastname: Lee
authors.forename: P D
authors.initials: PD
authors.lastname: Ryu
authors.forename: S Y
authors.initials: SY
authors.lastname: Lee
authors.forename: J E
authors.initials: JE
authors.lastname: Stern
mesh_terms: D015761:4-Aminopyridine / Q000494:pharmacology; D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology; D020747:Calcium Channels, T-Type / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology; D003712:Dendrites / Q000378:metabolism; D055724:Electrophysiological Phenomena / Q000187:drug effects / Q000502:physiology; D015870:Gene Expression / Q000235:genetics; D006978:Hypertension, Renovascular / Q000378:metabolism / Q000503:physiopathology*; D007031:Hypothalamus / Q000166:cytology / Q000503:physiopathology*; D008297:Male; D008526:Medulla Oblongata / Q000166:cytology / Q000502:physiology; D008564:Membrane Potentials / Q000502:physiology; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D009532:Nickel / Q000494:pharmacology; D010121:Oxytocin / Q000378:metabolism; D010286:Paraventricular Hypothalamic Nucleus / Q000166:cytology / Q000503:physiopathology; D018408:Patch-Clamp Techniques; D051381:Rats; D017208:Rats, Wistar; D051672:Shal Potassium Channels / Q000037:antagonists & inhibitors / Q000502:physiology*; D013564:Sympathetic Nervous System / Q000503:physiopathology*; D014667:Vasopressins / Q000378:metabolism
chemical_list: C500994:Cacna1g protein, rat; D002121:Calcium Channel Blockers; D020747:Calcium Channels, T-Type; D051672:Shal Potassium Channels; D014667:Vasopressins; D010121:Oxytocin; C022838:nickel chloride; D009532:Nickel; D015761:4-Aminopyridine