Horea Christian

Horea Christian
Dartmouth College · Department of Psychological and Brain Sciences

BSc | MSc | DrSc

About

33
Publications
6,101
Reads
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83
Citations
Introduction
My research focuses on functional Magnetic Resonance Imaging (fMRI), optogenetic deep brain stimulation, psychopharmacology, data analysis, scientific reproducibility, and scientific software management.
Additional affiliations
March 2020 - present
Massachusetts Institute of Technology
Position
  • PostDoc Position
August 2019 - February 2020
ETH Zurich
Position
  • PostDoc Position
November 2018 - present
ETH Zurich
Position
  • Lecturer
Description
  • Experimental Neuroimaging Topics: fMRI · Data structures · Data processing · Modelling
Education
January 2015 - July 2019
ETH Zurich
Field of study
  • Neuroscience & Biomedical Engineering
September 2011 - January 2014
Universität Heidelberg
Field of study
  • Molecular Biosciences & Neuroscience
September 2010 - January 2011
Saint Petersburg State University
Field of study
  • Neuroscience

Publications

Publications (33)
Article
Full-text available
Significance: Multiscale imaging holds particular relevance to neuroscience, where it helps integrate the cellular and molecular biological scale, which is most accessible to interventions, with holistic organ-level evaluations, most relevant with respect to function. Being inextricably interdisciplinary, multiscale imaging benefits substantially f...
Article
Full-text available
Ascending dopaminergic projections from neurons located in the Ventral Tegmental Area (VTA) are key to the etiology, dysfunction, and control of motivation, learning, and addiction. Due to the evolutionary conservation of this nucleus and the extensive use of mice as disease models, establishing an assay for VTA dopaminergic signaling in the mouse...
Poster
Full-text available
In biomedical imaging, between-subject comparability is attained at the voxel level via image registration. This process requires several data preparation steps, of which tissue segment-ation remains challenging in preclinical research. In preclinical neuroimaging, the process of brain extraction is the simplest tissue segmentation process, yet, re...
Article
Full-text available
DataLad is a Python-based tool for the joint management of code, data, and their relationship,built on top of a versatile system for data logistics (git-annex) and the most popular distributed version control system (Git). It adapts principles of open-source software development and distribution to address the technical challenges of data managemen...
Preprint
Full-text available
Brainhack is an innovative meeting format that promotes scientific collaboration and education in an open and inclusive environment. Departing from the formats of typical scientific workshops, these events are based on grassroots projects and training, and foster open and reproducible scientific practices. We describe here the multifaceted, lasting...
Poster
Full-text available
Magnetic Resonance Imaging (MRI) is a measurement method with high depth penetration, which enjoys extensive use in imaging organs with an intricate holistic mode of function, such as the brain. MRI has significant translational potential, constituting a mainstay of human brain imaging, and finding increased use in preclinica model animal research....
Preprint
Full-text available
The serotonergic system is widely implicated in affect regulation, and a common target for psychopharmacological interventions. Selective Serotonin Reuptake Inhibitors (SSRIs) are the foremost drug class for treating depression, as well as anxiety, phobia and other affective disorders. However, the functional mechanisms determining SSRI efficacy re...
Preprint
Full-text available
Ascending dopaminergic projections from neurons located in the Ventral Tegmental Area (VTA) are key to the etiology, dysfunction, and control of motivation, learning, and addiction. Due to evolutionary conservation of this nucleus and the extensive use of mice as disease models, establishing an assay for VTA dopaminergic signalling in the mouse bra...
Article
Full-text available
Large-scale research integration is contingent on seamless access to data in standardized formats. Standards enable researchers to understand external experiment structures, pool results, and apply homogeneous preprocessing and analysis workflows. Particularly, they facilitate these features without the need for numerous potentially confounding com...
Poster
Full-text available
As scientific work becomes increasingly collaborative and automated, reproducibility becomes increasingly vital for sharing and integrating scientific results. For most researchers, however, reproducibility remains a nebulous ideal, the benefits of which are considered more theoretical and indirect, than practical and immediate. Here we showcase an...
Article
Full-text available
In many research areas, the functioning of complex systems is probed by measuring stimulus-evoked responses. Commonly, stimulus train delivery is coordinated by in-house and/or proprietary solutions, which are often ill-documented, expensive, poorly reproducible, high-maintenance, and unsustainable. Here we present COSplay, a fully Free and Open So...
Preprint
Full-text available
Large-scale research integration is contingent on seamless access to data in standardized formats. Standards enable researchers to understand external experiment structures, pool results, and apply homogeneous preprocessing and analysis workflows. Particularly, they facilitate these features without the need for numerous potentially confounding com...
Preprint
Full-text available
Given the need for comparability across subjects and studies, the quality of registration to a standard space is crucial for the reliability of Magnetic Resonance Imaging (MRI), and in particular functional MRI (fMRI). Present small animal MRI workflows fall short in terms of quality and reliability, commonly utilizing high-level scripts optimized...
Article
Full-text available
Angiogenesis during wound healing is essential for tissue repair and also affected during cancer treatment by anti-angiogenic drugs. Here, we introduce a minimally invasive wound healing model in the mouse ear to assess angiogenesis with high spatiotemporal resolution in a longitudinal manner in vivo using two-photon microscopy in mice expressing G...
Article
Full-text available
The reliability of scientific results critically depends on reproducible and transparent data processing. Cross-subject and cross-study comparability of imaging data in general, and magnetic resonance imaging (MRI) data in particular, is contingent on the quality of registration to a standard reference space. In small animal MRI this is not adequat...
Article
The COSplayer is a pyboard-based device with specific input and output capabilities, designed to provide microsecond-range stimulus delivery in biomedical or psychological experiments. Based on a single trigger event (e.g. as obtained from most temporally precise measuerement devices), the COSplayer can deliver a fully configurable stimulus train...
Presentation
Full-text available
Slide Presentation on the topic of state-of-the-art fMRI data processing and standardization, and its applicability in the context of small animal imaging (applied to the specific example ena dinfrastructure at the Animal Imaging Center of the ETH Zurich and University of Zurich).
Poster
Full-text available
The increased availability of high-field Magnetic Resonance Imaging (MRI) systems, genetic vectors, and molecular biological tools enables a more highly resolved study of deep brain circuits. These circuits - including monoaminergic (e.g. serotonergic, dopaminergic, noradrenergic) and neuropeptidergic (e.g. oxytocinergic, vasopressinergic) systems...
Code
This repository exists to transparently document the statistical methods of the paper and ship them in a reexecutable format. To give academic credit please cite exclusively the “An in Vivo Wound Healing Model for the Characterization of the Angiogenic Process and its Modulation by Pharmacological Interventions” Paper, as it already references this...
Poster
Full-text available
As fMRI measurements are complex, expensive, and often target low-amplitude effects, the statistical optimization of stimulus sequences for specific experimental targets plays an integral role in the experiment design process. We provide an extremely flexible framework to perform such optimizations using the genetic algorithm (GA) introduced by Wag...
Poster
Full-text available
BehavioPy (github.com/TheChymera/behaviopy) is a novel software package providing evaluation, analysis, and plotting functionalities for behavioural and pyhsiological data, including simple parameterized one-function solutions for common use cases. Current data evaluation capabilities consist in flexible event tracking for video recordings, while a...
Conference Paper
Full-text available
LabbookDB is a relational database application framework for life sciences—providing an extendable schema and functions to conveniently add and retrieve information, and generate summaries. The core concept of LabbookDB is that wet work metadata commonly tracked in lab books or spreadsheets is more efficiently and more reliably stored in a relation...
Poster
Full-text available
The ascending serotonergic system is of great clinical importance due to its implication in affective disorders and their treatment. The origin of the majority of ascending serotonergic projections, the dorasl raphe (DR) represents a node with high degree centrality in the brain, and is evolutionarily well conserved. As such it is interesting to bo...
Article
Full-text available
Here, we examine the potential of positron emission tomography (PET), a non-invasive technique that detects the location of a small molecule within a subject in real-time with resolution in the micrometre range, in providing insight into the role of dopaminergic signalling in exploratory behaviours. Using a pilot of five adult mice, we recorded the...
Article
Full-text available
Gentoo is a GNU/Linux metadistribution designed to maximize and simplify user control of the software environment. All determinants of a Gentoo environment are recorded in a small number of plain-text configuration files, from which the software make-up of the system can be reconstructed entirely. As such, Gentoo constitutes a replicable and transp...
Article
Full-text available
The new frontier task (NFT) is a behavioural paradigm for rodents that provides insight into the motivations underlying exploration. In the NFT, subjects are provided the opportunity to climb out from their homecage and explore several platforms, called "frontiers". Classically, two versions of the task are employed; and they differ only in the ill...
Code
Behaviopy is a script suite leveraging the power of Python libraries such as SciPy, NumPy, Pandas, Psychopy, statsmodels, and Matplotlib, in order to analize behavioural data, alone or correlated with different modalities. Additionally, behaviopy provides basic and extendable event-tracking, allowing the on-line evaluation of bahavioural experiment...
Poster
Full-text available
Test the relationship between pupil diameter and LC activation in humans.
Thesis
Full-text available
Pupillometry is a simple physiological method with ample applications in neuropsychology. Electrophysiological studies indicate pupil dilation control via the locus coeruleus, the main site of norepinephrine synthesis in the brain. We use functional magnetic resonance imaging (fMRI) to test whether the pupil dilation response is a reliable indicato...

Questions

Question (1)
Question
In the effort to better relate neuronal mechanisms to states of mind, it makes sense to have - in addition to pharmacological classifications of drugs and imaging/physiology classifications of their effects - classifications of the states of mind they evoke, according to introspective reports.
I have been unable to find such a data-driven classification in the literature (I would imagine a cluster analysis of reported terms, or a factor analysis of ratings on statements could be appropriate). Instead, "subjective effects" classification seems to be restricted to single-substance profiling, and elsewise is remarkably top-down - based on ad hoc models by the same authoritative people or entities which commonly make psychoactive substances available to consumers (introducing confirmation bais). I'm wondering if there's anything else out there?

Network

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Projects

Projects (5)
Project
Implement cutting-edge workflow technologies, with optimal support for data and code sharing, to the small animal MRI environment.
Project
We develop a reference implementation for distributed reproducible publishing. As part of this we combine package management, data analysis, plotting, and document typesetting technologies and create scientific documents (e.g. papers, articles, slides) which are distributed in a source-code form, which is unambiguous and sufficient to reproduce — and hack! — them.
Project
Provide a free, open, transparent, and extendable framework which leverages the Scientific Python stack - to bring order to heterogeneous behavioural data sets and automate their processing and analysis.