H2020Индивидуална стипендия2021–2023

iMAC · Synaptic input mapping during cortical map plasticity

„Хоризонт 2020“ — Действия „Мария Склодовска-Кюри“

Период: 2021-04-15 → 2023-04-14
Финансиране от ЕС: 191 149 €
Участници: 1
Схема: MSCA-IF

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Накратко на български

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Този кратък обзор е генериран от изкуствен интелект

Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.

Резултати накратко

Synaptic input mapping during cortical map plasticity

For an individual to form a coherent sensory percept and subsequently exert a relevant behavioral response, various streams of sensory information need to be integrated. The brain’s neocortical neuronal circuits play a crucial role in this process. However, it is still enigmatic how the various information streams are assimilated and represented by individual neurons, let alone by synapses. Primary sensory cortices receive feedforward sensory information from first-order thalamic nuclei and contextual or feedback information from higher-order thalamic nuclei and long-range corticocortical pathways. Therefore, the pyramidal neurons in the primary sensory cortex integrate mainly two types of excitatory synaptic inputs, one relayed through feedforward thalamocortical and local corticocortical afferents and another relayed through feedback inputs from distinct thalamocortical and long-range corticocortical circuits. The synaptic connectivity motifs of these inputs and how they rearrange over time remain unknown. Our main objective was to map higher-order thalamocortical feedback inputs onto cortical pyramidal neurons in vivo using an all-optical approach. The second aim was to characterize the plasticity of sensory-evoked feedback synaptic activity.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз

Цел на проекта

The rodent primary somatosensory cortex (S1) contains a malleable topographic map, in which cortical columns functionally represent individual facial whiskers. When all whiskers but two are trimmed, the cortical representations of the two spared whiskers partially fuse. This fusion is associated and possibly facilitated by an increase in NMDAR-mediated dendritic nonlinearities (plateau potentials) in L2/3 neurons, which are dependent on inputs from the higher-order posteromedial thalamic complex (POm). It has been shown that plateau potentials generated by these inputs can promote plasticity of sensory-related synaptic inputs. However, the spatiotemporal relationships between the plateau potential-generating POm and the sensory-related synaptic inputs on L2/3 neurons, and possible rearrangements therein during plasticity, are not understood. Recently developed genetically encoded glutamate indicators (GEGIs), which the fellow was involved in, have enabled the visualization of active excitatory inputs. Here, the fellow proposes a novel methodology (iMAC, Input Mapping of Active Connections), where she combines two state-of-the-art optogenetics and optophysiology tools. A presynaptic light-sensitive opsin will allow optical activation of ascending POm inputs, while a postsynaptic GEGI will allow the visualization, i.e. mapping of the activated synapses on L2/3 pyramidal neurons. First, the fellow will establish a proto-map of these higher-order thalamocortical excitatory inputs in an ex vivo preparation, followed by a proof of principle in vivo in the awake mouse. Second, the fellow will compare the POm-driven synaptic maps with those recruited by whisker sensory stimulation in vivo. Third, she will determine how these rearrange upon sensory deprivation.Altogether, this work will investigate the spatiotemporal relationships between POm and sensory-driven inputs onto L2/3 neurons and reveal possible rearrangements therein related to cortical map plasticity.

Оригинален текст от CORDIS (на английски).

Участници

UNIVERSITE DE GENEVE · GeneveКоординаторШвейцария