title: Long-term potentiation in hippocampal oriens interneurons: postsynaptic induction, presynaptic expression and evaluation of candidate retrograde factors.
abstract: Several types of hippocampal interneurons exhibit a form of long-term potentiation (LTP) that depends on Ca(2+)-permeable AMPA receptors and group I metabotropic glutamate receptors. Several sources of evidence point to a presynaptic locus of LTP maintenance. The retrograde factor that triggers the expression of LTP remains unidentified. Here, we show that trains of action potentials in putative oriens-lacunosum-moleculare interneurons of the mouse CA1 region can induce long-lasting potentiation of stimulus-evoked excitatory postsynaptic currents that mimics LTP elicited by high-frequency afferent stimulation. We further report that blockers of nitric oxide production or TRPV1 receptors failed to prevent LTP induction. The present results add to the evidence that retrograde signalling underlies N-methyl-d-aspartate (NMDA) receptor-independent LTP in oriens interneurons, mediated by an unidentified factor.
authors.affiliation: UCL Institute of Neurology, University College London, , Queen Square, London WC1N 3BG, UK.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Nicholson
authors.forename: Dimitri M
authors.initials: DM
authors.lastname: Kullmann
mesh_terms: D000818:Animals; D001596:Benzylamines; D056547:CA1 Region, Hippocampal / Q000166:cytology / Q000502:physiology*; D002118:Calcium / Q000378:metabolism; D004224:Diterpenes; D004558:Electric Stimulation; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology*; D007395:Interneurons / Q000502:physiology*; D017774:Long-Term Potentiation / Q000502:physiology*; D051379:Mice; D018408:Patch-Clamp Techniques; D010721:Phosphinic Acids; D013569:Synapses / Q000378:metabolism / Q000502:physiology*
chemical_list: D001596:Benzylamines; D004224:Diterpenes; D010721:Phosphinic Acids; C468130:iodoresiniferatoxin; C083008:CGP 52432; D002118:Calcium
keywords: anti-Hebbian; interneurons; long-term potentiation