Horea ChristianDartmouth College · Department of Psychological and Brain Sciences
Horea Christian
BSc | MSc | DrSc
About
33
Publications
6,819
Reads
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155
Citations
Citations since 2017
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
August 2019 - February 2020
November 2018 - present
Position
- Lecturer
Description
- Experimental Neuroimaging Topics: fMRI · Data structures · Data processing · Modelling
Education
January 2015 - July 2019
September 2011 - January 2014
September 2010 - January 2011
Publications
Publications (33)
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 fr...
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...
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...
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...
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...
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....
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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).
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
Test the relationship between pupil diameter and LC activation in humans.
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)
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?
