title: Mg2+ dependence of membrane resistance increases evoked by NMDA in hippocampal neurones.
abstract: The response of granule cells and CA1 pyramidal neurones to NMDA was studied in the presence and absence of Mg2+ using an in vitro slice preparation. In the absence of Mg2+ the depolarizing response of hippocampal neurones to NMDA is accompanied by a decrease in input resistance. In the presence of Mg2+ ions, however, the response to NMDA is always associated with an apparent increase in input resistance. These results indicate that the action of NMDA is by a classical mechanism of conductance increase and are in agreement with the suggestion that the apparent increase in input resistance associated with NMDA depolarizations is the result of voltage-dependent channel block by Mg2+ of the NMDA evoked current.
mesh_terms: D000818:Animals; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology; D005071:Evoked Potentials / Q000187:drug effects; D006624:Hippocampus / Q000502:physiology*; D066298:In Vitro Techniques; D008274:Magnesium / Q000494:pharmacology*; D008564:Membrane Potentials / Q000187:drug effects; D016202:N-Methylaspartate; D009467:Neuromuscular Depolarizing Agents / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D010069:Oxadiazoles / Q000494:pharmacology; D011712:Pyramidal Tracts / Q000187:drug effects / Q000502:physiology; D016318:Quisqualic Acid; D051381:Rats
chemical_list: D009467:Neuromuscular Depolarizing Agents; D010069:Oxadiazoles; D001224:Aspartic Acid; D016202:N-Methylaspartate; D016318:Quisqualic Acid; D008274:Magnesium