pH-dependent modulation of N-methyl-D-aspartate receptor-mediated synaptic currents by histamine in rat hippocampus in vitro.
Modulation of excitatory postsynaptic currents by histamine was examined using whole cell recording methods in the CA1 region of slices of rat hippocampus. Histamine affected the N-methyl-D-aspartate (NMDA) component of the synaptic current in a pH-dependent manner: at lowered pH (7.2) it enhanced the NMDA-mediated synaptic currents while at raised pH (7.6) it reduced them. At a pH of 7.4 there was no significant action of histamine. Histamine failed to alter the non-NMDA component of the synaptic current. These results indicate that histamine acts at a postsynaptic site to modulate NMDA mediated synaptic currents in a pH dependent manner. This mechanism may have important implications for the pathophysiology of shifts in extracellular pH.
Saybasili
H
H
Physiologisches Institut II, Heinrich-Heine-Universität, Düsseldorf, Germany.
Stevens
D R
DR
Haas
H L
HL
D000818:Animals; D000831:Animals, Newborn; D005071:Evoked Potentials / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects*; D006632:Histamine / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D017729:Presynaptic Terminals / Q000187:drug effects*; D051381:Rats; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects*
D016194:Receptors, N-Methyl-D-Aspartate; D006632:Histamine