title: Effects of cyclic nucleotide-gated channels in vestibular nuclear neurons.
abstract: This study was designed to investigate the effects an 8-Br-cGMP on the neuronal activity of rat vestibular nuclear cells. Sprague-Dawley rats aged 14 to 16 days were decapitated under ether anesthesia. After treatment with pronase and thermolysin, the dissociated vestibular nuclear cells were transferred into a chamber on an inverted microscope. Spontaneous action potentials and potassium currents were recorded by standard patch-clamp techniques under current and voltage-clamp modes. Twelve vestibular nuclear cells revealed excitatory responses to 1-5 µM of 8-Br-cGMP, and 3 neurons did not respond to 8-Br-cGMP. Whole potassium currents of vestibular nuclear cells were decreased by 8-Br-cGMP (n=12). After calcium-dependent potassium currents were blocked by tetraethylammonium, the potassium currents were not decreased by 8-Br-cGMP. These experimental results suggest that 8-Br-cGMP changes the neuronal activity of vestibular nuclear cells by blocking the calcium-dependent potassium currents that underlie the afterhyperpolarization.
authors.affiliation: Department of Emergency Medicine, Chonnam National University Medical School, Gwangju, Korea.
authors.forename: Tag
authors.initials: T
authors.lastname: Heo
authors.forename: Sujeong
authors.initials: S
authors.lastname: Jang
authors.forename: Han-Seong
authors.initials: HS
authors.lastname: Jeong
authors.forename: Jong-Seong
authors.initials: JS
authors.lastname: Park