Ştefan Mihalaş
A5072126704- Neural dynamics and brain function
- Neuroscience and Neuropharmacology Research
- Visual perception and processing mechanisms
- Advanced Memory and Neural Computing
- Functional Brain Connectivity Studies
- Photoreceptor and optogenetics research
- Neuroscience and Neural Engineering
- Cell Image Analysis Techniques
- Neural Networks and Applications
- Receptor Mechanisms and Signaling
- Visual Attention and Saliency Detection
- Neurobiology and Insect Physiology Research
- Memory and Neural Mechanisms
- Olfactory and Sensory Function Studies
- stochastic dynamics and bifurcation
- Neural Networks and Reservoir Computing
- Advanced Fluorescence Microscopy Techniques
- Computational Drug Discovery Methods
- Retinal Development and Disorders
- Advanced Neuroimaging Techniques and Applications
- Nonlinear Dynamics and Pattern Formation
- Tactile and Sensory Interactions
- Multisensory perception and integration
- Advanced Vision and Imaging
- Neural and Behavioral Psychology Studies
Allen Institute
2016-2025
Allen Institute for Brain Science
2015-2024
University of Washington Applied Physics Laboratory
2018-2024
Applied Mathematics (United States)
2018-2024
University of Washington
2018-2023
Seattle University
2020
Jülich Aachen Research Alliance
2016
Johns Hopkins University
2008-2014
Kennedy Krieger Institute
2011
California Institute of Technology
2010
Significance Noninvasive brain imaging holds great promise for expanding our capabilities of treating human neurologic and psychiatric disorders. However, key limitations exist in human-only studies, the ability to use animal models would greatly advance understanding function. Mice offer sophisticated genetic molecular methodology, but correlating these data functional mouse has remained a major hurdle. This study is first, knowledge, whole-brain show large-scale architecture with...
Abstract There is a high diversity of neuronal types in the mammalian neocortex. To facilitate construction system models with multiple cell types, we generate database point associated Allen Cell Types Database. We construct set generalized leaky integrate-and-fire (GLIF) increasing complexity to reproduce spiking behaviors 645 recorded neurons from 16 transgenic lines. The more complex have an increased capacity predict behavior hold-out stimuli. use unsupervised methods classify and find...
Generating a comprehensive description of cortical networks requires large-scale, systematic approach. To that end, we have begun pipeline project using multipatch electrophysiology, supplemented with two-photon optogenetics, to characterize connectivity and synaptic signaling between classes neurons in adult mouse primary visual cortex (V1) human cortex. We focus on producing results detailed enough for the generation computational models enabling comparison future studies. Here, report our...
Learning to predict rewards based on environmental cues is essential for survival. It believed that animals learn by updating predictions whenever the outcome deviates from expectations, and such reward prediction errors (RPEs) are signaled mesolimbic dopamine system-a key controller of learning. However, instead learning prospective RPEs, can infer retrospective cause rewards. Hence, whether conveys a causal associative signal sometimes resembles RPE remains unknown. We developed an...
We report that developmental competition between sympathetic neurons for survival is critically dependent on a sensitization process initiated by target innervation and mediated series of feedback loops. Target-derived nerve growth factor (NGF) promoted expression its own receptor TrkA in mouse rat prolonged TrkA-mediated signals. NGF also controlled brain-derived neurotrophic neurotrophin-4, which, through the p75, can kill neighboring with low retrograde NGF-TrkA signaling whereas high are...
For simulations of neural networks, there is a trade-off between the size network that can be simulated and complexity model used for individual neurons. In this study, we describe generalization leaky integrate-and-fire produces wide variety spiking behaviors while still being analytically solvable firings. different parameter values, or bursting, tonic, phasic adapting responses, depolarizing hyperpolarizing after potentials so forth. The consists diagonalizable set linear differential...
The cerebral cortex of the mouse has become one most important systems for studying information processing and neural correlates behavior. Multiple studies have examined first stages visual cortical processing: primary (V1) its thalamic inputs from dorsal lateral geniculate nucleus (dLGN), but more rarely in posterior (LP) mice. single-unit surveys dLGN V1, both with electrophysiology two-photon calcium imaging, described receptive fields anesthetized animals. Increasingly, awake animals are...
Summary To understand how the brain processes sensory information to guide behavior, we must know stimulus representations are transformed throughout visual cortex. Here report an open, large-scale physiological survey of neural activity in awake mouse cortex: Allen Brain Observatory Visual Coding dataset. This publicly available dataset includes cortical from nearly 60,000 neurons collected 6 areas, 4 layers, and 12 transgenic lines 221 adult mice, response a systematic set stimuli. Using...
The evolutionarily conserved default mode network (DMN) is a distributed set of brain regions coactivated during resting states that vulnerable to disorders. How disease affects the DMN unknown, but detailed anatomical descriptions could provide clues. Mice offer an opportunity investigate structural connectivity across spatial scales with cell-type resolution. We co-registered maps from functional magnetic resonance imaging and axonal tracing experiments into 3D Allen mouse reference atlas....
Knowledge of mesoscopic brain connectivity is important for understanding inter- and intraregion information processing. Models structural are typically constructed analyzed with the assumption that regions homogeneous. We instead use Allen Mouse Brain Connectivity Atlas to construct a model whole-brain at scale 100 μm voxels. The data consist 428 anterograde tracing experiments in wild type C57BL/6J mice, mapping fluorescently labeled neuronal projections brain-wide. Inferring spatial this...
Cortical circuits can flexibly change with experience and learning, but the effects on specific cell types, including distinct inhibitory are not well understood. Here we investigated how excitatory VIP cells in layer 2/3 of mouse visual cortex were impacted by context a behavioral task. Mice learned detection task set eight natural scene images. Subsequently, during 2-photon imaging experiments, mice performed these familiar images three sets novel Strikingly, temporal dynamics activity...
Despite advances in experimental techniques and accumulation of large datasets concerning the composition properties cortex, quantitative modeling cortical circuits under in-vivo-like conditions remains challenging. Here we report publicly release a biophysically detailed circuit model layer 4 mouse primary visual receiving thalamo-cortical inputs. The 45,000-neuron was subjected to battery stimuli, results were compared published work new vivo experiments. Simulations reproduced variety...
The detection of novel stimuli is critical to learn and survive in a dynamic environment. Though powerfully affect brain activity, their impact on specific cell types circuits not well understood. Disinhibition one candidate mechanism for novelty-induced enhancements activity. Here we characterize the stimulus novelty disinhibitory circuit components using longitudinal 2-photon calcium imaging Vip, Sst, excitatory populations mouse visual cortex. Mice behavioral task with that become highly...
Changes in synaptic strength that underlie memory formation the CNS are initiated by pulses of Ca2+ flowing through NMDA-type glutamate receptors into postsynaptic spines. Differences duration and size determine whether a synapse is potentiated or depressed after repetitive activity. Calmodulin (CaM) major effector protein binds up to four ions. CaM with bound can activate at least six signaling enzymes spine. In fluctuating cytosolic Ca2+, large fraction free fewer than Binding targets...
During the acquisition of memories, influx Ca2+ into postsynaptic spine through pores activated N-methyl-D-aspartate-type glutamate receptors triggers processes that change strength excitatory synapses. The pattern Ca2+influx during first few seconds activity is interpreted within Ca2+-dependent signaling network such synaptic eventually either potentiated or depressed. Many critical enzymes control plasticity,including Ca2+/calmodulin-dependent protein kinase II (CaMKII), are regulated by...