Zinc reduces dentate granule cell hyperexcitability in epileptic humans.
The hippocampi of epileptic patients with medial temporal lobe epilepsy exhibit a characteristic pattern of anatomical changes including cell loss and sprouting of the granule cell axons, the mossy fibers, into the inner molecular layer of the dentate. In addition to glutamate, mossy fibers release Zn2+. In the present study we investigated the action of Zn2+ on excitatory synaptic potentials in the dentate granule cells of patients with medial temporal lobe epilepsy. We show here that Zn2+ limits the duration of excitatory responses in these cells, probably by blocking the N-methyl-D-aspartate (NMDA) receptors. Zinc may, therefore, play an important role in limiting epileptiform activity in this issue.
Williamson
A
A
Section of Neurosurgery, Yale University School of Medicine, New Haven, CT 06520, USA.
Spencer
D
D
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D018891:Dentate Gyrus / Q000187:drug effects* / Q000473:pathology; D004833:Epilepsy, Temporal Lobe / Q000188:drug therapy* / Q000473:pathology; D005071:Evoked Potentials / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D009474:Neurons / Q000187:drug effects*; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors; D012598:Sclerosis; D009435:Synaptic Transmission / Q000187:drug effects*; D015032:Zinc / Q000627:therapeutic use*
D016194:Receptors, N-Methyl-D-Aspartate; D015763:2-Amino-5-phosphonovalerate; D015032:Zinc