Magnesium removal induces paroxysmal neuronal firing and NMDA receptor-mediated neuronal degeneration in cortical cultures

Neurosci Lett. 1990 Jul 31;115(2-3):313-7. doi: 10.1016/0304-3940(90)90474-n.


Removal of extracellular Mg2+ triggered the onset of repetitive excitatory discharges in cultured murine cortical neurons, detected by recording with patch electrodes in the whole cell configuration. The discharges were suppressed by 100 microM D-2-amino-5-phosphonovalerate. Over the next 24-72 h substantial numbers of neurons, but not glia, degenerated, releasing lactate dehydrogenase to the bathing medium. The neuronal death induced by removal of extracellular Mg2+ could be attenuated by either 3 microM tetrodotoxin or 50 microM dextrorphan, and thus likely reflects excessive activation of N-methyl-D-aspartate receptors triggered by excitatory discharges. This Mg2+ removal model may be a useful model in which to study certain aspects of epileptic neocortical injury.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • 2-Amino-5-phosphonovalerate / pharmacology
  • Action Potentials
  • Animals
  • Cells, Cultured
  • Cerebral Cortex / metabolism
  • Cerebral Cortex / physiology*
  • Magnesium / physiology*
  • Mice
  • Receptors, N-Methyl-D-Aspartate / drug effects
  • Receptors, N-Methyl-D-Aspartate / physiology*


  • Receptors, N-Methyl-D-Aspartate
  • 2-Amino-5-phosphonovalerate
  • Magnesium