Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

Some interneurons of the hippocampus exhibit NMDA receptor-independent long-term potentiation (LTP) that is induced by presynaptic glutamate release when the postsynaptic membrane potential is hyperpolarized. This "anti-Hebbian" form of LTP is prevented by postsynaptic depolarization or by blocking AMPA and kainate receptors. Although both AMPA and kainate receptors are expressed in hippocampal interneurons, their relative roles in anti-Hebbian LTP are not known. Because interneuron diversity potentially conceals simple rules underlying different forms of plasticity, we focus on glutamatergic synapses onto a subset of interneurons with dendrites in stratum oriens and a main ascending axon that projects to stratum lacunosum moleculare, the oriens-lacunosum moleculare (O-LM) cells. We show that anti-Hebbian LTP in O-LM interneurons has consistent induction and expression properties, and is prevented by selective inhibition of AMPA receptors. The majority of the ionotropic glutamatergic synaptic current in these cells is mediated by inwardly rectifying Ca(2+)-permeable AMPA receptors. Although GluR5-containing kainate receptors contribute to synaptic currents at high stimulus frequency, they are not required for LTP induction. Glutamatergic synapses on O-LM cells thus behave in a homogeneous manner and exhibit LTP dependent on Ca(2+)-permeable AMPA receptors.

Original publication

DOI

10.1523/JNEUROSCI.3251-08.2009

Type

Journal article

Journal

J Neurosci

Publication Date

28/01/2009

Volume

29

Pages

939 - 950

Keywords

Anesthetics, Local, Animals, Biophysics, Electric Stimulation, Excitatory Amino Acid Antagonists, Excitatory Postsynaptic Potentials, GABA Antagonists, Hippocampus, In Vitro Techniques, Interneurons, Long-Term Potentiation, Lysine, Male, Neural Inhibition, Patch-Clamp Techniques, Phosphinic Acids, Picrotoxin, Propanolamines, Rats, Rats, Sprague-Dawley, Receptors, AMPA, Receptors, Kainic Acid, Tetrodotoxin