title: Acidic pH modulation of Na+ channels in trigeminal mesencephalic nucleus neurons.
abstract: Cell bodies of trigeminal mesencephalic nucleus (Vmes) neurons are located within the central nervous system, and therefore, peripheral as well as central acidosis can modulate the excitability of Vmes neurons. Here, we report the effect of acidic pH on voltage-gated Na channels in acutely isolated rat Vmes neurons using a conventional whole-cell patch clamp technique. Acidic pH (pH 6.0) slightly but significantly shifted both the activation and steady-state fast inactivation relationships toward depolarized potentials. However, acidic pH (pH 6.0) had a minor effect on the inactivation kinetics of voltage-gated Na channels. Less sensitivity of voltage-gated Na channels to acidic pH may allow Vmes neurons to transduce the precise proprioceptive information even under acidic pH conditions.
authors.affiliation: aDepartment of Pharmacology, School of Dentistry bBrain Science and Engineering Institute, Kyungpook National University, Daegu, Republic of Korea.
authors.forename: In-Sik
authors.initials: IS
authors.lastname: Kang
authors.forename: Jin-Hwa
authors.initials: JH
authors.lastname: Cho
authors.forename: In-Sun
authors.initials: IS
authors.lastname: Choi
authors.forename: Do-Yeon
authors.initials: DY
authors.lastname: Kim
authors.forename: Il-Sung
authors.initials: IS
authors.lastname: Jang
mesh_terms: D000143:Acids; D000818:Animals; D000831:Animals, Newborn; D001703:Biophysics; D019256:Cadmium Chloride / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002478:Cells, Cultured; D004558:Electric Stimulation; D006863:Hydrogen-Ion Concentration; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D018408:Patch-Clamp Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley; D026941:Sodium Channel Blockers / Q000494:pharmacology; D015222:Sodium Channels / Q000378:metabolism / Q000502:physiology*; D013779:Tetrodotoxin / Q000494:pharmacology; D066266:Trigeminal Motor Nucleus / Q000166:cytology*
chemical_list: D000143:Acids; D002121:Calcium Channel Blockers; D026941:Sodium Channel Blockers; D015222:Sodium Channels; D013779:Tetrodotoxin; D019256:Cadmium Chloride