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Hitchens, T. K.

Publications and source records attributed to Hitchens, T. K..

2 recordsLinked to original sources

An Open Access Resource for Marmoset Neuroscientific Apparatus

The use of the common marmoset (Callithrix jacchus) for neuroscientific inquiry has grown precipitously over the past two decades. Despite windfalls of grant support from funding initiatives in North America, Europe, and Asia to model human brain diseases in the marmoset, marmoset- specific apparatus are of sparse availability from commercial vendors and thus are often developed and reside within individual laboratories. Through our collective research efforts, we have designed and vetted myriad designs for awake or anesthetized magnetic resonance imaging (MRI), positron emission tomography (PET), computed tomography (CT), as well as focused ultrasound (FUS), electrophysiology, optical imaging, surgery, and behavior in marmosets across the age- span. This resource makes these designs openly available, reducing the burden of de novo development across the marmoset field. The computer-aided-design (CAD) files are publicly available through the Marmoset Brain Connectome (MBC) resource (https://www.marmosetbrainconnectome.org/apparatus/) and include dozens of downloadable CAD assemblies, software and online calculators for marmoset neuroscience. In addition, we make available a variety of vetted touchscreen and task-based fMRI code and stimuli. Here, we highlight the online interface and the development and validation of a few yet unpublished resources: Software to automatically extract the head morphology of a marmoset from a CT and produce a 3D printable helmet for awake neuroimaging, and the design and validation of 8-channel and 14- channel receive arrays for imaging deep structures during anatomical and functional MRI.

bioengineering↗

Epigenetic MRI: Noninvasive Imaging of DNA Methylation in the Brain

Both neuronal and genetic mechanisms regulate brain function. While there are excellent methods to study neuronal activity in vivo, there are no nondestructive methods to measure global gene expression in living brains. Here we present a method, epigenetic magnetic resonance imaging (eMRI), that overcomes this limitation via direct imaging of DNA methylation, a major gene expression regulator. eMRI exploits the methionine metabolic pathways for DNA methylation to label genomic DNA through 13C-enriched diets. A novel 13C magnetic resonance spectroscopic imaging method then maps the spatial distribution of labeled DNA. We validated eMRI using pigs, whose brains have stronger similarity to humans in volume and anatomy than rodents, and confirmed efficient 13C labeling of brain DNA. We also discovered strong regional differences in global DNA methylation. Just as MRI measurements of regional neuronal activity have had a transformational effect on neuroscience, we expect that the eMRI signal as a surrogate for regional gene expression will enable many new investigations into the roles of gene expression in human brain function, behavior, and disease.

bioengineering↗