Membrane And Cellular Biophysics And BiochemistryHyperpolarization-activated (Ih) current in mouse vestibular primary neuronsChabbert, ChristianCA; Chambard, Jean-Marie; Valmier, Jean; Sans, Alain; Desmadryl, GillesAuthor Information INSERM U432, UM2 cp 089, place E. Bataillon, 34095 Montpellier, Cedex 5, France CACorresponding Author Received 30 May 2001; accepted 27 June 2001 Neuroreport: August 28, 2001 - Volume 12 - Issue 12 - p 2701-2704 Buy Abstract The presence of a hyperpolarization-activated inward current (Ih) was investigated in mouse vestibular primary neurons using the whole-cell patch-clamp technique. In current-clamp configuration, injection of hyperpolarizing currents induced variations of membrane voltage with prominent time-dependent rectification increasing with current amplitudes. This effect was abolished by 2 mM Cs+ or 100 μM ZD7288. In voltage-clamp configuration, hyperpolarization pulses from −60 mV to −140 mV triggered a slow activating and non inactivating inward current that was sensitive to the two blockers, but insensitive to 5 mM Ba2+. Changing Na+ and K+ concentrations demonstrated that Ih current is carried by both these monovalent cations. This is the first demonstration of a Ih current in vestibular primary neurons. © 2001 Lippincott Williams & Wilkins, Inc.