Topic: freely moving mice

Miniature head-mounted microscopes have enabled in vivo optical measurements of neural activity in freely moving animals, allowing neuroscientists to study the neural basis of behaviors that are difficult to recapitulate in head-fixed preparations like social interaction and navigation. Existing head-mounted microscopes for small animals are limited to small fields of view (< 1mm2), which limit the number of neurons that can be recorded simultaneously to at most several hundred. However, understanding how behavior is controlled by large neural populations across brain regions requires simul

Sensory discrimination tasks are valuable tools for investigating neuronal perception and learning mechanisms. While novel somatosensory discrimination tasks have been developed for electrophysiological or imaging studies in head-fixed mice, there remains a scarcity of tasks incorporating neurophysiological recordings within a more ecologically realistic setting involving freely moving animals. This study introduces a tactile discrimination task for freely moving mice, integrating electrophysiology and calcium imaging with cellular resolution. In this go/no-go paradigm, mice learn to discrimin

Neurons in sensory areas are tuned to various input features, and tuning properties reveal essential aspects of the computation performed by the neuronal population. In the post-subiculum (PoSub), neurons are modulated by the animal’s head-direction (HD), and most pyramidal neurons are fine tuned to a specific direction. Other cell types, especially fast-spiking neurons, are less specifically tuned but are generally still modulated by HD. By recording from ensembles of neurons in the PoSub in freely moving mice with linear silicon probes, making it possible to determine precise anatomical loca

Primary sensory cortical areas are characterized by low-level representations of sensory inputs, but whether these representations are stable over time or are continuously renewed is unclear. The head-direction (HD) signal is essential for the spatial navigation system, where it has previously been found that place representation is unstable over long periods of time. In the cortex, the HD signal is processed by the postsubiculum (PoSub). HD cells constitute a vast majority of PoSub principal neurons. Each HD cell fires towards a specific direction of the head of the animal in the horizontal p

Aims. Though electrophysiological methods allow recording neuronal activity from freely moving animals, the localization and type of cells recorded can only be deduced from indirect markers. Two-photon microscopy can provide exact localization and immediate identification of cell types. Our aim was to develop and test an imaging modality that is capable of deep-tissue long-term two-photon imaging while being light and compact for a mouse to carry while freely moving in its environment.Methods. All experimental procedures were approved by the French ethics committee (APAFiS #30959) and were con

Jointly designing computational signal extraction and optics allows scalability to larger fields-of-view, lighter and faster functional neuroimaging devices. Using this insight, we developed a modular, mesoscale light field (MesoLF) imaging hardware and software solution (Nature Methods 20(4), 2023) that allows recording from thousands of neurons within volumes of ⌀ 4 × 0.2 mm located at depths of up to 350 μm in the mouse cortex. MesoLF achieves an imaging rate of 18 volumes per second and an effective voxel rate of approximately 40 Megavoxels per second. By using our optical design and compu

In social species, signals from conspecifics can help interpret ambiguous sensory information crucial for survival, such as locating food sources or detecting predators. To investigate the influence of conspecific cues on goal-directed decision-making, we devised a two-alternative forced-choice task for pairs of freely moving mice positioned facing each other. Water-restricted mice were trained to discriminate between visual stimuli indicating the location of a water reward. To evaluate their reliance on conspecific cues under conditions of uncertainty, we positioned the reward on the same sid

The kinematics of straight-trajectory forward locomotion has been extensively studied, but the motor strategies used for changing direction have been rarely investigated. We recently found in the mouse that the stimulation of V2a reticulospinal neurons in the gigantocellular nucleus (V2aGRN) leads to locomotor turning. Nevertheless, the complete body movements associated with this induced behavior, and their relevance in the context of spontaneous locomotion, remain underexplored. We address this here, by characterizing and comparing, with 3D motion capture at high spatial and temporal resolut

Manipulating neuronal activity in the central nervous system through electrical stimulation is crucial for the clinical treatment of neurological disorders and for basic neuroscience research. Traditional electrode implantations might carry the risk of complications, infection, and damage caused by micromovements during daily activities. Recently, accumulating research has been focusing on developing neuromodulation technologies with less invasiveness. Multiple magnetoelectric stimulation approaches based on magnetoelectrical nanoparticles have been developed in the last decade. However, the r