Sensory-evoked LTP driven by dendritic plateau potentials in vivo

Frédéric Gambino, Stéphane Pagès, Vassilis Kehayas, Daniela Baptista, Roberta Tatti, Alan Carleton, Anthony Holtmaat
Nature. 2014-08-31; 515(7525): 116-119
DOI: 10.1038/nature13664

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1. Nature. 2014 Nov 6;515(7525):116-9. doi: 10.1038/nature13664. Epub 2014 Aug 31.

Sensory-evoked LTP driven by dendritic plateau potentials in vivo.

Gambino F(1), Pagès S(2), Kehayas V(3), Baptista D(4), Tatti R(3), Carleton A(4),
Holtmaat A(4).

Author information:
(1)1] Department of Basic Neurosciences and the Center for Neuroscience, CMU,
University of Geneva, 1 rue Michel Servet, 1211 Geneva, Switzerland [2] [3]
Institute for Interdisciplinary Neuroscience (IINS), UMR 5297 CNRS and University
of Bordeaux, 146 rue Léo-Saignat, 33077 Bordeaux, France.
(2)1] Department of Basic Neurosciences and the Center for Neuroscience, CMU,
University of Geneva, 1 rue Michel Servet, 1211 Geneva, Switzerland [2].
(3)1] Department of Basic Neurosciences and the Center for Neuroscience, CMU,
University of Geneva, 1 rue Michel Servet, 1211 Geneva, Switzerland [2] Lemanic
Neuroscience Doctoral School, 1 rue Michel Servet, 1211 Geneva, Switzerland.
(4)Department of Basic Neurosciences and the Center for Neuroscience, CMU,
University of Geneva, 1 rue Michel Servet, 1211 Geneva, Switzerland.

Long-term synaptic potentiation (LTP) is thought to be a key process in cortical
synaptic network plasticity and memory formation. Hebbian forms of LTP depend on
strong postsynaptic depolarization, which in many models is generated by action
potentials that propagate back from the soma into dendrites. However, local
dendritic depolarization has been shown to mediate these forms of LTP as well. As
pyramidal cells in supragranular layers of the somatosensory cortex spike
infrequently, it is unclear which of the two mechanisms prevails for those cells
in vivo. Using whole-cell recordings in the mouse somatosensory cortex in vivo,
we demonstrate that rhythmic sensory whisker stimulation efficiently induces
synaptic LTP in layer 2/3 (L2/3) pyramidal cells in the absence of somatic
spikes. The induction of LTP depended on the occurrence of NMDAR
(N-methyl-d-aspartate receptor)-mediated long-lasting depolarizations, which bear
similarities to dendritic plateau potentials. In addition, we show that whisker
stimuli recruit synaptic networks that originate from the posteromedial complex
of the thalamus (POm). Photostimulation of channelrhodopsin-2 expressing POm
neurons generated NMDAR-mediated plateau potentials, whereas the inhibition of
POm activity during rhythmic whisker stimulation suppressed the generation of
those potentials and prevented whisker-evoked LTP. Taken together, our data
provide evidence for sensory-driven synaptic LTP in vivo, in the absence of
somatic spiking. Instead, LTP is mediated by plateau potentials that are
generated through the cooperative activity of lemniscal and paralemniscal
synaptic circuitry.

DOI: 10.1038/nature13664
PMID: 25174710 [Indexed for MEDLINE]

Auteurs Bordeaux Neurocampus