Anti-Hebbian long-term potentiation in the hippocampal feedback inhibitory circuit.
Long-term potentiation (LTP), which approximates Hebb's postulate of associative learning, typically requires depolarization-dependent glutamate receptors of the NMDA (N-methyl-D-aspartate) subtype. However, in some neurons, LTP depends instead on calcium-permeable AMPA-type receptors. This is paradoxical because intracellular polyamines block such receptors during depolarization. We report that LTP at synapses on hippocampal interneurons mediating feedback inhibition is "anti-Hebbian":Itis induced by presynaptic activity but prevented by postsynaptic depolarization. Anti-Hebbian LTP may occur in interneurons that are silent during periods of intense pyramidal cell firing, such as sharp waves, and lead to their altered activation during theta activity.
Lamsa
Karri P
KP
Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK.
Heeroma
Joost H
JH
Somogyi
Peter
P
Rusakov
Dmitri A
DA
Kullmann
Dimitri M
DM
D000818:Animals; D004558:Electric Stimulation; D019706:Excitatory Postsynaptic Potentials; D006624:Hippocampus / Q000166:cytology / Q000502:physiology*; D007395:Interneurons / Q000502:physiology*; D017774:Long-Term Potentiation; D008297:Male; D008564:Membrane Potentials; D009433:Neural Inhibition / Q000502:physiology*; D018408:Patch-Clamp Techniques; D017966:Pyramidal Cells / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018091:Receptors, AMPA / Q000502:physiology; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology; D013096:Spermine / Q000031:analogs & derivatives / Q000494:pharmacology; D013569:Synapses / Q000502:physiology*
D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; D013096:Spermine