Technology Resources Initiative Paper of the Month

The Successor Representation: Its Computational Logic and Neural Substrates. J Neurosci.

In this paper, Gershman presents and builds upon a reinforcement learning algorithm first proposed by Peter Dayan in 1993, called the successor representation, which solves some important problems that previous classes of reinforcement learning algorithms have had.  Recent research has supported the idea that humans and other animals use successor representations for learning and decision making under some conditions and has proposed that dopaminergic mechanisms could build successor representations in the brain. [Read More]

Customizable, wireless and implantable neural probe design and fabrication via 3D printing. Nature Protocols.

Detailed in this protocol are custom manufacturing techniques for rapidly 3D-printing large number of optogenetic probes of any length and number of shanks. Also included are instructions for low-cost, custom, wireless harnesses to couple with probes for offsite optical manipulation. [Read More]

Insights into distinct signaling profiles of the µOR activated by diverse agonists. Nat Chem Biology.

The TRUPATH BRET2 assay is a single and comprehensive platform of 14 G protein biosensors that allows for unambiguous measurement of heterotrimeric G protein dissociation following agonist-induced receptor stimulation. Because individual G protein subunits have distinct functional characteristics, directly monitoring their activation and signaling profiles provides new opportunities for revealing previously uncharacterized actions of GPCR ligands. [Read More]

Single-Cell Chromatin Modification Profiling Reveals Increased Epigenetic Variations with Aging. Cell.

A group of researchers from Stanford University employed a multiplexed mass cytometry to profile the epigenetic landscape and measure a broad array of global chromatin modifications in human cells at the single-cell level. The EpiTOF technology provides new opportunities for identifying cell-specific epigenetic changes associated with altered physiological and pathological states. [Read More]

Polony gels enable amplifiable DNA stamping and spatial transcriptomics of chronic pain. Cell.

Fu*, Sun*, Dong* et. al. generated and validated a novel polony-based ‘stamp gel’ that uses common lab equipment and enzymatic replication to produce copies of the 1 µm resolution barcoded array slide that is used for spatial transcriptomic capture. Taken together, polony gel stamping is poised to increase accessibility of high-resolution spatial transcriptomics. [Read More]

Rapid Quantum Magnetic IL-6 Point-of-Care Assay in Patients Hospitalized with COVID-19. Diagnostics.

The quantum diamond microscope system is a sensitive method to detect target proteins in a short time compared to similar immunocomplex-based detection methods (e.g. traditional ELISAs). This method does not require removal of unbound beads or extensive wash steps thus providing relatively fast and sensitive assay for measuring protein targets in pre-clinical and clinical applications. [Read More]

Nanoparticle single-cell multiomic readouts reveal that cell heterogeneity influences lipid nanoparticle-mediated messenger RNA delivery. Nature Nanotechnology.

Researchers from the Georgia Institute of Technology and Emory University’s School of Medicine have developed a system that makes nanoparticle delivery to subsets of cells more predictable by combining DNA barcoding with a nanoparticle delivery system called single-cell nanoparticle targeting-sequencing (SENT-seq). Using SENT-seq, the investigators identified how different nanoparticles deliver DNA barcodes and mRNA into cells to affect the transcriptome and proteome with single cell resolution. [Read More]

Transgenic mice for in vivo epigenome editing with CRISPR-based systems. Nature Methods.

Gemberling et al. generated and validated two new Cre-dependent transgenic mouse lines harboring LSL-dCas9-p300 (gene activator/histone acetyltransferase) and LSL-dCas9-KRAB (gene repressor/histone methyltransferase). The authors demonstrated that guide RNAs targeting gene enhancers and the gene promoter are effective at modulating both histone modification state and gene transcription. [Read More]

Dense functional and molecular readout of a circuit hub in sensory cortex. Science.

The Comprehensive readout of activity and cell type markers (CRACK) platform combines multi-area two photon calcium imaging microscopy with hybridization chain reaction–fluorescence in situ hybridization (HCR-FISH) to label and track mRNA. CRACK allows researchers to first observe the electrical firing of neurons in the brain of a live mouse during a behavioral task, and then track the expression of specific genes in slices of the animal’s brain, ultimately linking specific cells and their molecular signatures to behaviors. [Read More]

SMART: An Open-Source Extension of WholeBrain for Intact Mouse Brain Registration and Segmentation. eNeuro.

Jin et al. presents an optimized protocol for Fos staining, a marker of neuronal activation, in a cleared mouse brain and provide an open-source R package called SMART (Semi-Manual Alignment to Reference Templates) as an extension to the Wholebrain pipeline (PMID: 29203898). SMART is designed to make whole-brain activity mapping more accessible to researchers looking to implement the technique and analysis into their research program. [Read More]