title: GluA1 phosphorylation alters evoked firing pattern in vivo.
abstract: AMPA and NMDA receptors convey fast synaptic transmission in the CNS. Their relative contribution to synaptic output and phosphorylation state regulate synaptic plasticity. The AMPA receptor subunit GluA1 is central in synaptic plasticity. Phosphorylation of GluA1 regulates channel properties and trafficking. The firing rate averaged over several hundred ms is used to monitor cellular input. However, plasticity requires the timing of spiking within a few ms; therefore, it is important to understand how phosphorylation governs these events. Here, we investigate whether the GluA1 phosphorylation (p-GluA1) alters the spiking patterns of CA1 cells in vivo. The antidepressant Tianeptine was used for inducing p-GluA1, which resulted in enhanced AMPA-evoked spiking. By comparing the spiking patterns of AMPA-evoked activity with matched firing rates, we show that the spike-trains after Tianeptine application show characteristic features, distinguishing from spike-trains triggered by strong AMPA stimulation. The interspike-interval distributions are different between the two groups, suggesting that neuronal output may differ when new inputs are activated compared to increasing the gain of previously activated receptors. Furthermore, we also show that NMDA evokes spiking with different patterns to AMPA spike-trains. These results support the role of the modulation of NMDAR/AMPAR ratio and p-GluA1 in plasticity and temporal coding.
authors.affiliation: Bay Zoltán Foundation for Applied Research, BAYGEN, Közép Fasor 41, Szeged 6727, Hungary.
authors.forename: Balázs
authors.initials: B
authors.lastname: Barkóczi
authors.forename: Gábor
authors.initials: G
authors.lastname: Juhász
authors.forename: Robert G
authors.initials: RG
authors.lastname: Averkin
authors.forename: Imre
authors.initials: I
authors.lastname: Vörös
authors.forename: Petra
authors.initials: P
authors.lastname: Vertes
authors.forename: Botond
authors.initials: B
authors.lastname: Penke
authors.forename: Viktor
authors.initials: V
authors.lastname: Szegedi
mesh_terms: D000818:Animals; D004558:Electric Stimulation; D006624:Hippocampus / Q000378:metabolism* / Q000502:physiology; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology; D008297:Male; D009473:Neuronal Plasticity / Q000502:physiology; D009474:Neurons / Q000378:metabolism / Q000502:physiology*; D010766:Phosphorylation; D051381:Rats; D017208:Rats, Wistar; D018091:Receptors, AMPA / Q000378:metabolism*; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology; D013841:Thiazepines / Q000494:pharmacology; D013997:Time Factors
chemical_list: D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; D013841:Thiazepines; C050504:tianeptine