Topic: 2-photon imaging

Recent studies have proposed that neural circuits generate a task manifold: i.e., a subset of the neural state-space to which neural activity is confined as an animal performs a task. Thus, discovering and characterising these manifolds from experimental data can shed light on the neural computations unfolding within the brain during behavioural tasks. In parallel, neuroscience has seen a recent surge of interest into fitting dynamical systems to experimental data with the goal of reverse-engineering neural circuits. Yet, common neural manifolds frameworks often do not take into account that n

Binocular rivalry, a phenomenon in which perception switches between stimuli that are presented to different eyes, is commonly employed to study consciousness-related effects in humans and non-human primates. As mice are becoming increasingly popular as model organisms to study visual perception, recent studies have started to investigate the neuronal underpinnings of mouse binocular vision. However, to our knowledge, no systematic investigation of whether mice experience binocular rivalry-like perception when presented with binocularly conflicting stimuli exists. Here, we recorded neuronal ac

Neural circuits are reconfigured to tune behaviour to the prevailing conditions. For instance, resting Xenopus laevis tadpoles start swimming when appropriately stimulated, but halt if the same stimulation is applied during ongoing locomotion. These opposite responses can be explained by a reconfiguration of the sensorimotor circuit, so that the same sensory pathway can exert either an excitatory or inhibitory effect on locomotion, depending on the current motor state. This form of neuronal network reconfiguration could be shared by different neuronal networks and across different species.Prev

Orexin neurons originate in the lateral hypothalamus, receive many inputs, and project throughout the brain. This puts them in an ideal position to integrate large amounts of information and signal them toward desired targets. We hypothesized that arousal, which impacts a variety of internal states and behaviours, could be one of these signals that orexin neurons transmit. To test this, we investigated the causal and correlative links between orexin neurons and pupil size, which is often taken as a readout of arousal. Optogenetic stimulation, 2-photon imaging, photometry, ablation, and pharmac

Semantic memory and abstraction of knowledge from experience are thought to involve communication between the hippocampus and neocortex. The hippocampus encodes novel episodes using sparse and orthogonal neural representations, which form and stabilize within ~10 minutes in a novel environment. Recent studies have shown that several neocortical areas, including the retrosplenial cortex (RSC), primary somatosensory cortex (S1), and primary visual cortex (V1) contain sparse neural coding correlated to spatial location in one-dimensional environments. This spatial coding depends on an intact hipp

While the hippocampus is known to encode physical position through place cells, substantial evidence indicates that hippocampal neurons also respond to a variety of other non-spatial sensory information. We explore the hypothesis that these representations emerge through generic computations implemented by the hippocampus that actively learn from the statistical structure of experience. Theoretical work has shown that place cell coding arises as a special case during spatial exploration in networks trained to learn sparse, compressed representations, due to the local correlations present in th

High-fat diet (HFD) and obesity are associated with cognitive dysfunction, depression, and increased anxiety, impacting emotional and social behavior. Additionally, HFD affects the immune system, leading to low-level chronic inflammation involving microglia, the brain’s resident immune cells. Inhibiting microglia alters social behavior, and improves HFD-induced metabolic effects. Hence, this raises the question of whether microglial cells mediate HFD-dependent changes in behavioral outcomes.To investigate the effect of HFD-driven microglial activation on neuronal function, HFD adult CX3CR1GFP/

Novelty is an attribute of a stimulus that lacks a pre-existing representation and novelty detection involves a series of interrelated processes, each playing a unique role. Different medial temporal lobe structures including the hippocampus have been highly implicated to play a major role in novelty detection. In this project, we aim to understand how CA1 of the hippocampus encodes novelty and familiarity signals induced by unimodal and multimodal sensory stimuli and what are the processes that mediate the transition between novelty and familiarity. We plan to use a multisensory cue delivery

Recent studies showed that flexible, ultra-thin, polyimide electrodes implanted in mouse V1 elicit chronically stable intracortical microstimulation (ICM) with low activation threshold and high biocompatibility, demonstrating their promising use as prosthetics for visual restoration. However, these works did not explore the full repertoire of parameters that can shape the ICM. Besides, to achieve precise spatial encoding of the visual field, it is necessary to identify the stimulation conditions that lead to localized neuronal activation around the stimulation site(s). We have developed a pipe

A key goal underlying the FAIR principles is to enhance reusability of research data. Yet in the field of animal neurophysiology this is challenging due to a high degree of heterogeneity and complexity in the experimental instruments, techniques and analytic tools used. Consequently, this diversity leads to different approaches to data organisation, a wide range of file formats and countless variations of lab-specific metadata that can be difficult to interpret, ultimately preventing efficient data reuse. Here we propose a workflow for standardising and sharing datasets from different electrop

Astrocytes play a fundamental role in numerous neural processes. In this study, we present preliminary data from ex vivo human cortical astrocytes obtained from Temporal lobe resections for epilepsy treatment and examined using whole cell patch clamp and 2-photon imaging techniques. Calcium (Ca2+) imaging reveals that these astrocytes exhibit a high frequency of Ca2+ transients in their fine processes compared to whole-cell responses, a finding consistent with astrocyte activity recorded in rodents. While the morphology of human astrocytes bore similarities to their rodent counterparts, they d