HEИндивидуална стипендия2024–2025

FBIimaging · Organization of long-range inputs in sensory cortex for top-down modulation of tactile perception

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

Период: 2024-01-01 → 2025-12-31
Финансиране от ЕС: 195 915 €
Участници: 2
Схема: HORIZON-TMA-MSCA-PF-EF

Линиите свързват координатора с партньорите.

Накратко на български

Връзките между различните зони на мозъка определят как възприемаме допира, например защо един и същ стимул се усеща различно според вниманието ни. Разбирането на тези процеси помага да се обяснят нарушенията в сетивната чувствителност и дефицитите на вниманието.

Този кратък обзор е генериран от изкуствен интелект

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

Резултати накратко

Organization of long-range inputs in sensory cortex for top-down modulation of tactile perception

Perception is the process through which the brain transforms sensory signals into meaningful experiences that guide behavior. In mammals, tactile perception is essential for interacting with the environment, navigation, and social behavior. Tactile signals are conveyed from peripheral receptors to the primary somatosensory cortex (S1), a key cortical region for processing touch. Importantly, perception is not a faithful copy of the external world: identical sensory stimuli can be perceived differently depending on the internal state of the brain. Internal brain states, such as attention, expectation, motivation, and behavioral context, are known to influence sensory processing and perceptual sensitivity. Disruptions in these state-dependent processes are associated with perceptual abnormalities, including attentional deficits and altered sensory sensitivity, which can lead to maladaptive behavior. At the cortical level, such modulation relies on long-range feedback projections from higher-order cortical and thalamic regions that convey contextual information and shape sensory processing. Despite clear anatomical evidence for these pathways, their dynamic organization during perception remained poorly understood. This project addressed this gap by characterizing feedback input to S1 during tactile perception and determining how it modulates cortical state and perceptual sensitivity. By combining detection tasks performed at perceptual threshold with wide-field axonal calcium imaging, the project revealed how long-range feedback dynamically shapes sensory processing in vivo and biases perceptual outcome.

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

Цел на проекта

The sensory cortex plays a crucial role in detecting and interpreting environmental stimuli. Tactile inputs from the peripheral organs are transmitted through the thalamus to the primary somatosensory cortex (S1), where they are integrated with long-range projections from higher-order brain regions, defined as feedback (top-down) inputs. Top-down control has been proposed to mediate contextual or attentional modulation of sensory processing. The host laboratory has shown that layer 5 pyramidal neurons (L5-PNs) in S1 exhibited dendritic regenerative potentials, so-called calcium spikes, when mice detect tactile stimuli, and their manipulation altered the mouses perception threshold. Interestingly, the L5-PNs distal-apical dendrites, where calcium spikes originate, are extensively innervated by axonal projections from higher-order cortical and thalamic areas. In light of this evidence, I hypothesize that long-range inputs to S1 modulate tactile detection via facilitating dendritic calcium spikes in L5-PNs. To test this hypothesis, I will determine the localization and timing of the long-range feedback inputs reaching the apical dendrites of S1 L5-PNs, which covary with the tactile detection sensitivity. Furthermore, I will test the context dependence of the long-range inputs. I will employ a whisker detection paradigm, where mice are trained to detect single whisker deflections to obtain water rewards. I will combine one-photon wide-field imaging and state-of-the-art genetic tools to visualize the glutamatergic inputs in distal dendrites or the axonal calcium activity in long-range projections. My study will provide new insights into the neuronal mechanisms underlying contextual modulation of perception by shedding light on the integrative properties of cortical pyramidal neuron dendrites.

Оригинален текст от CORDIS (на английски).

Участници

CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS · ParisКоординаторФранция
UNIVERSITE DE BORDEAUX · BordeauxФранция