Persistent transcription- and translation-dependent long-term potentiation induced by mGluR1 in hippocampal interneurons.
Hippocampal interneurons synchronize the activity of large neuronal ensembles during memory consolidation. Although the latter process is manifested as increases in synaptic efficacy which require new protein synthesis in pyramidal neurons, it is unknown whether such enduring plasticity occurs in interneurons. Here, we uncover a long-term potentiation (LTP) of transmission at individual interneuron excitatory synapses which persists for at least 24 h, after repetitive activation of type-1 metabotropic glutamate receptors [mGluR1-mediated chemical late LTP (cL-LTP(mGluR1))]. cL-LTP(mGluR1) involves presynaptic and postsynaptic expression mechanisms and requires both transcription and translation via phosphoinositide 3-kinase/mammalian target of rapamycin and MAP kinase kinase-extracellular signal-regulated protein kinase signaling pathways. Moreover, cL-LTP(mGluR1) involves translational control at the level of initiation as it is prevented by hippuristanol, an inhibitor of eIF4A, and facilitated in mice lacking the cap-dependent translational repressor, 4E-BP. Our results reveal novel mechanisms of long-term synaptic plasticity that are transcription and translation-dependent in inhibitory interneurons, indicating that persistent synaptic modifications in interneuron circuits may contribute to hippocampal-dependent cognitive processes.
Ran
Israeli
I
Groupe de Recherche sur le Système Nerveux Central and Département de Physiologie, Université de Montréal, Montreal, Quebec H3C 3J7, Canada.
Laplante
Isabel
I
Bourgeois
Catherine
C
Pépin
Julie
J
Lacaille
Philippe
P
Costa-Mattioli
Mauro
M
Pelletier
Jerry
J
Sonenberg
Nahum
N
Lacaille
Jean-Claude
JC
D000818:Animals; D006624:Hippocampus / Q000502:physiology*; D007395:Interneurons / Q000502:physiology*; D017774:Long-Term Potentiation / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D014176:Protein Biosynthesis / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018094:Receptors, Metabotropic Glutamate / Q000235:genetics / Q000502:physiology*; D014158:Transcription, Genetic / Q000502:physiology*
D018094:Receptors, Metabotropic Glutamate; C104077:metabotropic glutamate receptor type 1