Biology subjects

Veit, J.

Publications and source records attributed to Veit, J..

5 recordsLinked to original sources

bioRxiv2026

An inhibitory circuit motif governs oscillation-dependent coupling between aperiodic activity and neural spiking

Behavior arises from coordinated neural population activity, yet how spiking and synaptic interactions give rise to extracellular population signals, including local field potentials (LFPs), remains unresolved. Beyond oscillations, aperiodic LFP activity has emerged as a putative marker of neural excitability, but its neurophysiological basis and relationship to neural spiking are unclear. Here we employed optogenetics and simultaneous single-unit and LFP recordings in mouse visual cortex to quantify how spiking relates to oscillatory and aperiodic dynamics across cortical states and behavioral contexts. To test circuit mechanisms, we optogenetically suppressed the activity of somatostatin (SST), vasoactive intestinal peptide (VIP), or parvalbumin (PV) interneurons to causally manipulate inhibitory drive, thereby dissociating spiking, aperiodic activity, and gamma oscillations. Across conditions, aperiodic activity tracked neural spiking in a manner consistent with computational predictions, but this coupling was strongly context- and state-dependent: high oscillatory synchrony attenuated the relationship between aperiodic activity and spiking. These results demonstrate that state-dependent changes in neural excitability shift circuit activity between oscillation- and aperiodic-dominated regimes, placing principled limits on interpreting neural mass signals at synaptic or cellular scales.

neuroscience↗

bioRxiv2025

Feature-tuned synaptic inputs to somatostatin interneurons drive context-dependent processing

Mapping neural computation onto the functional microarchitecture of sensory circuits is essential for understanding how brain circuits transform input signals into coherent percepts. Many higher-order perceptual processes emerge in the cortex, yet relatively little is known about how specific connectivity motifs give rise to these computations. To address this challenge, we combined single cell and population-level physiological recordings and perturbation methods to map a context-dependent cortical computation onto the synaptic microarchitecture of the mouse primary visual cortex (V1). We demonstrate a precise, recurrent circuit between cortical pyramidal cells (PCs) and somatostatin (SST) inhibitory interneurons that mediates context-driven figure/ground modulation in V1. Through a like-to-like connectivity rule from PCs and SSTs, this circuit explains SSTs visual encoding properties and their resulting impact on contextual modulation in V1. These findings reveal key synaptic and circuit mechanisms that may underlie the earliest stages of scene segmentation in the visual cortex. Moreover, they raise the notion that feature-specific excitatory-inhibitory microcircuitry from PC to SSTs could be a general strategy that the cortex exploits to give rise to higher level computations.

neuroscience↗

bioRxiv2024

Balanced bidirectional optogenetics reveals the causal impact of cortical temporal dynamics in sensory perception

Whether the fast temporal dynamics of neural activity in brain circuits causally drive perception and cognition remains one of most longstanding unresolved questions in neuroscience1-6. While some theories posit a timing code in which dynamics on the millisecond timescale is central to brain function, others instead argue that mean firing rates over more extended periods (a rate code) carry most of the relevant information. Existing tools, such as optogenetics, can be used to alter temporal structure of neural dynamics7, but they invariably change mean firing rates, leaving the interpretation of such experiments ambiguous. Here we developed and validated a new approach based on balanced, bidirectional optogenetics that can alter temporal structure of neural dynamics while mitigating effects on mean activity. Using this new approach, we found that selectively altering cortical temporal dynamics substantially reduced performance in a sensory perceptual task. These results demonstrate that endogenous temporal dynamics in the cortex are causally required for perception and behavior. More generally, this new bidirectional optogenetic approach should be broadly useful for disentangling the causal impact of different timescales of neural dynamics on behavior.

neuroscience↗

bioRxiv2021

VIP neurons desynchronize cortical assemblies

Gamma band synchronization can facilitate local and long-range communication in neural circuits. In the primary visual cortex (V1) the strength of synchronization on the local level is strongly tuned to the contrast, size and center/surround orientation of grating stimuli. On the global level, the synchronization of gamma oscillations across the retinotopic map crucially depends on matched stimulus properties in the corresponding locations in the visual field. Although these features of V1 gamma rhythms are likely to be crucial for how they might support cortico-cortical communication and visual perception, their neural basis remains largely unknown. We hypothesized VIP disinhibitory interneurons, which shape other tuning properties in V1 by inhibiting SST neurons, may be responsible for tuning local gamma band power and global gamma synchronization. To test these ideas, we combined multi-electrode electrophysiology, cell-type specific optogenetic suppression of VIP neurons and computational modeling. Contrary to expectations, our data show that on the local level, VIP activity has no role in tuning gamma power to stimulus properties; rather, it scales the gain of gamma oscillations linearly across stimulus space and across behavioral state. Conversely, on the global level, VIP neurons specifically suppress gamma synchronization (as measured by spectral coherence) between spatially separated cortical ensembles when they are processing non-matched stimulus features. A straightforward computational model of V1 shows that like-to-like connectivity across retinotopic space, and specific, but powerful VIPSST inhibition are sufficient to capture these seemingly opposed effects. These data demonstrate how VIP neurons differentially impact local and global properties of gamma rhythms depending on the global statistics of the retinal image. VIP neurons may thus construct temporal filters in the gamma band for spatially continuous image features, such as contours, to facilitate the downstream generation of coherent visual percepts.

neuroscience↗

bioRxiv2021

Antagonistic inhibitory subnetworks control cooperation and competition across cortical space

The cortical microcircuit can dynamically adjust to dramatic changes in the strength, scale, and complexity of its input. In the primary visual cortex (V1), pyramidal cells (PCs) integrate widely across space when signals are weak, but narrowly when signals are strong, a phenomenon known as contrast-dependent surround suppression. Theoretical work has proposed that local interneurons could mediate a shift from cooperation to competition of PCs across cortical space, underlying this computation. We combined calcium imaging and electrophysiology to constrain a stabilized supralinear network model that explains how the four principal cell types in layer 2/3 (L2/3) of mouse V1- somatostatin (SST), parvalbumin (PV), and vasoactive intestinal peptide (VIP) interneurons, and PCs- transform inputs from layer 4 (L4) PCs to encode drifting gratings of varying size and contrast. Using bidirectional optogenetic perturbations, we confirmed key predictions of the model. Our data and modeling showed that recurrent amplification drives a transition from a positive PC[->]VIP{dashv}SST{dashv}PC feedback loop at small size and low contrast to a negative PC[->]SST{dashv}PC feedback loop at large size and high contrast to contribute to this flexible computation. This may represent a widespread mechanism for gating competition across cortical space to optimally meet task demands.

neuroscience↗