A5054501530- Neural dynamics and brain function
- Neuroscience and Neuropharmacology Research
- Photoreceptor and optogenetics research
- Neural Networks and Applications
- Advanced Memory and Neural Computing
- Semantic Web and Ontologies
- Advanced Algebra and Logic
- Advanced Fluorescence Microscopy Techniques
- Logic, Reasoning, and Knowledge
- Visual perception and processing mechanisms
- Benford’s Law and Fraud Detection
- Zebrafish Biomedical Research Applications
- Mathematical and Theoretical Analysis
- Computability, Logic, AI Algorithms
- Genetic Mapping and Diversity in Plants and Animals
- Neuroscience, Education and Cognitive Function
- Genetic Associations and Epidemiology
- stochastic dynamics and bifurcation
- Genetic and phenotypic traits in livestock
- Gaussian Processes and Bayesian Inference
- Blind Source Separation Techniques
- Retinal Development and Disorders
- Neural Networks and Reservoir Computing
- EEG and Brain-Computer Interfaces
Columbia University
2022-2024
Center for Theoretical Biological Physics
2022-2023
The University of Queensland
2017-2022
University of Auckland
2016-2017
Spontaneous activity is a fundamental characteristic of the developing nervous system. Intriguingly, it often takes form multiple structured assemblies neurons. Such can even in absence afferent input, for instance zebrafish optic tectum after bilateral enucleation early life. While development neural based on input has been theoretically well-studied, less clear how they could arise systems without input. Here we show that recurrent network binary threshold neurons with initially random...
The pattern of neural activity evoked by a stimulus can be substantially affected ongoing spontaneous activity. Separating these two types is particularly important for calcium imaging data given the slow temporal dynamics indicators. Here we present statistical model that decouples stimulus-driven from low dimensional in this case. identifies hidden factors giving rise to while jointly estimating tuning properties account confounding effects introduce. By applying our zebrafish optic tectum...
Abstract Discovering how neural computations are implemented in the cortex at level of monosynaptic connectivity requires probing for existence synapses from possibly thousands presynaptic candidate neurons. Two-photon optogenetics has been shown to be a promising technology mapping such connections via serial stimulation neurons with single-cell resolution. However, this approach is limited its ability uncover large scales because stimulating one-by-one prohibitively long experiments. Here...
The circuit mechanisms that give rise to direction selectivity in the retina have been studied extensively but how is established retinorecipient areas of brain less well understood. Using functional imaging larval zebrafish we examine motion encoded by populations neurons at three layers optic tectum; retinal ganglion cell axons (RGCs), a layer superficial inhibitory interneurons (SINs), and periventricular (PVNs), which constitute majority tectum. We show representation transformed each...
Abstract The Jordan decomposition theorem states that every function $f \colon \, [0,1] \to \mathbb {R}$ of bounded variation can be written as the difference two non-decreasing functions. Combining this fact with a result Lebesgue, is differentiable almost everywhere in sense Lebesgue measure. We analyze strength these theorems setting reverse mathematics. Over $\mathsf {RCA}_{0}$ , stronger version Jordan’s where all functions are continuous equivalent to {ACA}_0$ while stated ${\textsf...
The semantics for counterfactuals due to David Lewis has been challenged on the basis of unlikely, or impossible, events. Such events may skew a given similarity order in favour those possible worlds which exhibit them. By updating relational structure model according ceteris paribus clause one forces out, natural manner, do not satisfy requirements clause. We develop logic counterfactual reasoning capable performing such actions, and offer several alternative (relaxed) interpretations...
Abstract Two-photon optogenetics has transformed our ability to probe the structure and function of neural circuits. However, achieving precise optogenetic control ensemble activity remained fundamentally constrained by problem off-target stimulation (OTS): inadvertent activation nearby non-target neurons due imperfect confinement light onto target neurons. Here we propose a novel computational approach this called Bayesian optimisation. Our uses nonparametric inference model responses...
The Jordan decomposition theorem states that every function $f \colon [0,1] \to \mathbb{R}$ of bounded variation can be written as the difference two non-decreasing functions. Combining this fact with a result Lebesgue, is differentiable almost everywhere in sense Lebesgue measure. We analyze strength these theorems setting reverse mathematics. Over $\mathsf{RCA}_0$, stronger version Jordan's where all functions are continuous equivalent to $\mathsf{ACA}_0$, while stated $\mathsf{WKL}_0$. on...
Monosynaptic connectivity mapping is crucial for building circuit-level models of neural computation. Two-photon optogenetic stimulation, when combined with whole-cell recording, enables large-scale physiological circuit parameters. In this experimental setup, recorded postsynaptic currents are used to infer the presence and strength connections. For many cell types, nearby connections those we expect be strongest. However, expresses opsin, optical excitation cells can induce direct...
Abstract The pattern of neural activity evoked by a stimulus can be substantially affected ongoing spontaneous activity. Separating these two types is particularly important for calcium imaging data given the slow temporal dynamics indicators. Here we present statistical model that decouples stimulus-driven from low dimensional in this case. identifies hidden factors giving rise to while jointly estimating tuning properties account confounding effects introduce. By applying our zebrafish...
Abstract Monosynaptic connectivity mapping is crucial for building circuit-level models of neural computation. Two-photon optogenetic stimulation, when combined with whole-cell recordings, has the potential to map monosynaptic at an unprecedented scale. However, nearby connections poses a challenge, due stimulation artifacts. When postsynaptic cell expresses opsin, optical excitation can directly induce current in patched cell, confounding measurements. This problem most severe pairs, where...
Understanding brain function requires disentangling the high-dimensional activity of populations neurons. Calcium imaging is an increasingly popular technique for monitoring such neural activity, but computational tools interpreting extracted calcium signals are lacking. While there has been a substantial development factor analysis-type methods spike train analysis, similar targeted at data only beginning to emerge. Here we develop flexible modeling framework that identifies low-dimensional...