RT Journal Article
SR Electronic
T1 Long-Term Enhancement of Neuronal Excitability and Temporal Fidelity Mediated by Metabotropic Glutamate Receptor Subtype 5
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 10238
OP 10248
DO 10.1523/JNEUROSCI.23-32-10238.2003
VO 23
IS 32
A1 Valérie Sourdet
A1 Michaël Russier
A1 Gaël Daoudal
A1 Norbert Ankri
A1 Dominique Debanne
YR 2003
UL http://www.jneurosci.org/content/23/32/10238.abstract
AB The cellular substrate for memory is generally attributed to long-lasting changes in synaptic strength. We report here that synaptic or pharmacological activation of the metabotropic glutamate receptor subtype 5 (mGluR5) induces long-term potentiation of intrinsic excitability (LTP-IE) in layer V pyramidal neurons. mGluR5-dependent LTP-IE was associated with a persistent reduction of the afterhyperpolarization (AHP) outward current (IAHP), resulting in the potentiation of EPSP-spike coupling. Apamin occluded induction of LTP-IE, indicating that downregulation of small conductance calcium-dependent potassium (SK) channels mediates this process. In addition to the improved reliability of the input-output function, LTP-IE led to increased temporal precision. The induced reduction of IAHP accelerated the rate of membrane depolarization preceding each action potential and subsequently decreased the jitter of the neuronal discharge. We conclude that mGluR5-dependent LTP-IE not only promotes the spread of excitation in the cortical network but also persistently enhances the temporal fidelity of the neuronal message.