Spermine depresses NMDA, K/AMPA and GABAA-mediated synaptic transmission in the rat hippocampal slice preparation.
The effects of spermine, an endogenous polyamine, were examined in area CA1 of the rat hippocampal slice preparation. Spermine, at low millimolar concentrations, rapidly and potently depressed NMDA and K/AMPA-mediated population EPSPs, and GABA-mediated monosynaptic population IPSPs. These effects contrast with its well-known potentiation of NMDA currents at lower concentrations. Our results raise the possibility that the large intracellular stores of spermine that are released after various neural insults could act as an endogenous neuroprotective mechanism by limiting excessive calcium entry.
DiScenna
P G
PG
Neurobiology Department, Northeastern Ohio Universities College of Medicine, Rootstown 44272.
Ferchmin
P A
PA
Eterovic
V A
VA
Teyler
T J
TJ
D000818:Animals; D015220:Calcium Channels / Q000187:drug effects; D005071:Evoked Potentials / Q000187:drug effects; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology*; D058787:GABA-A Receptor Antagonists; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D051381:Rats; D018091:Receptors, AMPA / Q000037:antagonists & inhibitors; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors; D013096:Spermine / Q000494:pharmacology*; D013569:Synapses / Q000187:drug effects / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects*
D015220:Calcium Channels; D018691:Excitatory Amino Acid Antagonists; D058787:GABA-A Receptor Antagonists; D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; D013096:Spermine