title: Effect of hypertonic saline on rat hypothalamic paraventricular nucleus magnocellular neurons in vitro.
abstract: The effect of hypertonic saline on rat hypothalamic paraventricular nucleus (PVN) magnocellular neurons was examined using a whole-cell patch-clamp technique. Under a current-clamp, 58/68 of magnocellular neurons were depolarized by hypertonic stimulation. Under a voltage-clamp, hypertonic saline produced an inward current via increased non-selective cationic conductance and shifting of the reversal potential to more positive values. Furthermore, hypertonic saline even without a change in osmolality increased spontaneous excitatory postsynaptic currents (sEPSCs). A bath application of CNQX almost completely blocked EPSCs. Extracellular application of gadolinium blocked the hypertonic saline- and mannitol-induced response. These results suggest that PVN magnocellular neurons are responsive to osmolality and Na+ concentrations. Hypertonic saline excited PVN magnocellular neurons via osmo-reception, Na+ -detection, and excitatory glutamatergic synaptic input.
authors.affiliation: Department of Physiology, Miyazaki Medical College, 5200 Kihara, Kiyotake-cho, Miyazaki-gun, Miyazaki 889-1692, Japan.
authors.forename: De-Lai
authors.initials: DL
authors.lastname: Qiu
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Shirasaka
authors.forename: Chun-Ping
authors.initials: CP
authors.lastname: Chu
authors.forename: Shoichi
authors.initials: S
authors.lastname: Watanabe
authors.forename: Nan-Shou
authors.initials: NS
authors.lastname: Yu
authors.forename: Takahiko
authors.initials: T
authors.lastname: Katoh
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kannan
mesh_terms: D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D000200:Action Potentials / Q000187:drug effects / Q000502:physiology*; D000344:Afferent Pathways / Q000187:drug effects / Q000502:physiology; D000818:Animals; D000831:Animals, Newborn; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D045604:Extracellular Fluid / Q000187:drug effects / Q000378:metabolism; D005682:Gadolinium / Q000494:pharmacology; D018698:Glutamic Acid / Q000378:metabolism; D066298:In Vitro Techniques; D008353:Mannitol / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D009994:Osmolar Concentration; D010286:Paraventricular Hypothalamic Nucleus / Q000187:drug effects / Q000502:physiology*; D018408:Patch-Clamp Techniques; D051381:Rats; D017208:Rats, Wistar; D012462:Saline Solution, Hypertonic / Q000494:pharmacology*; D012964:Sodium / Q000378:metabolism; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology; D014882:Water-Electrolyte Balance / Q000187:drug effects / Q000502:physiology*
chemical_list: D018691:Excitatory Amino Acid Antagonists; D012462:Saline Solution, Hypertonic; D018698:Glutamic Acid; D008353:Mannitol; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D012964:Sodium; D005682:Gadolinium