Topic: voltage imaging

In nature, diverse sensory signals fluctuate in time and in space. Odors, for example, are distorted by wind into narrow filaments. When multiple spatially distinct odor sources exist, these filaments interleave but do not intermix. Such odor landscapes pose complementary challenges to animals – such as the fruit fly – that depend on olfaction to find food or mating partners. First, to select the best odor to track back to its source, the olfactory system must compare information from different filaments over relatively long timescales. Second, to remain on high alert to unexpected changes, su

Hippocampal pyramidal (PY) spiking sequences link temporally contiguous memories by encoding sensory cues as well as temporal intervals between them, constructing trajectories across ‘memory-space’. But what is the role of inhibition – particularly parvalbumin (PV) and somatostatin expressing (SST) interneurons (INs) - in shaping such sensory and temporal representations? We pioneered longitudinal, high-frequency voltage imaging in vivo on the CA1 of PV-Cre and SST-Cre mice while they performed an odor-cued delayed non-match-to-sample task (DNMS), shown to yield odor-specific PY sequences duri

In recent years, many calcium and voltage imaging methods have been developed in pursuit of a central goal of systems neuroscience: to study the function of large populations of neurons. Projective imaging methods, such as Bessel imaging, are a promising class of approaches in pursuit of this goal. These methods simultaneously record neural activity at a wide range of depths in the brain, effectively allowing scientists to image a volume of brain tissue. However, this added capability comes with a trade-off: all observed signals from the volume are projected onto a 2D imaging plane. Therefore,

A change in pairwise spike train correlations is a well-established neural correlate of a shift in brain state, and as such has been the topic of intense study. However, while the explosion in population recording has provided a wealth of data to measure spike train correlations and their state dependence, there continues to be ambiguity in the biological mechanisms that mediate changes in correlated activity. One reason for this lack of understanding is the vast set of possible circuit and cellular realities that can support correlated spiking activity. To provide insight into how circuit and

Dendrites play a fundamental role in neuronal computation. It is thought that functionally defined regions of dendritic branches, termed ‘dendritic computational units’ are used to decode information transmitted by synaptic input. This information is encoded by the corresponding dendritic output, to perform complex neuronal computations. To investigate dendric input-output in vivo, it is necessary to record synaptic input and dendritic output simultaneously. To do this we perform simultaneous glutamate imaging and voltage imaging from the spiny dendrites of single Purkinje neurons in awake mic

Understanding synaptic connectivity is crucial for understanding how neuronal networks contribute to specific brain functions. However, current methods can measure the functionality only of a limited number of synaptic connections in sufficient detail. Therefore, we evaluated the applicability of a voltage imaging method in acute rat hippocampal slices to map unitary synaptic connections between CA3 neurons by using Voltron, which can detect both action potentials and small subthreshold events, such as unitary EPSPs. These connections are crucial for major hippocampal memory functions; however

The state-of-the-art techniques for all-optical interrogation of neuronal circuits in vivo typically combine two-photon (2P) calcium imaging and digital holography to precisely activate target neurons with sculpted light patterns. This approach is however limited in speed and in throughput, ultimately due to the intrinsic constraints of digital holography. We employed acousto-optic deflectors (AOD)-based 2P approaches (“ULoVE”, Villette et al. 2019; “3D-CASH”, Akemann et al. 2022) to simultaneously record and perturb neuronal activity in awake head-fixed mice across single planes or three-dime