We use cookies to understand how you use our site and to improve your experience. This includes personalizing content and advertising. To learn more, click here. By continuing to use our site, you accept our use of cookies. Cookie Policy.

Features Partner Sites Information LinkXpress
Sign In
Advertise with Us
GLOBETECH PUBLISHING LLC

Download Mobile App




New Reagent Helps Map Neural Connections in Brain

By MedImaging International staff writers
Posted on 29 Apr 2016
Print article
Image: MRV tracing in a mouse thalamus (Photo courtesy of the Salk Institute for Biological Studies).
Image: MRV tracing in a mouse thalamus (Photo courtesy of the Salk Institute for Biological Studies).
An improved rabies virus tracer visualizes neural circuitry in the brain, helping to understand more about motor diseases and neurodevelopmental disorders.

Researchers at the Salk Institute for Biological Studies (La Jolla, CA, USA) have engineered an optimized glycoprotein (OG) variant of the monosynaptic rabies virus (MRV) system that improves trans-synaptic efficiency. The new approach is based on a genetic modification of the virus that allows infection to be targeted to specific types of neurons, thus allowing virus spread to be controlled. The result is that while neurons are illuminated across the entire brain, the tracer reagent illuminates only those that are directly connected to neurons of interest.

The oG variant is a codon-optimized chimeric glycoprotein that merges the transmembrane-cytoplasmic domain of the B19G rabies virus, and the extracellular domain of the Pasteur virus strain glycoprotein. The resulting oG variant increases tracing efficiency for long-distance input neurons by up to 20-fold--when compared to B19G alone--allowing more complete study of monosynaptic input neural networks in the brain. The study describing the improved technique was published on April 14, 2016, in Cell Reports.

“To truly understand brain function, we have to understand how different types of neurons are connected to each other across many distant brain areas. The rabies tracing methods we have developed made that possible, but we were only labeling a fraction of all of the connections,” said senior author Professor Edward Callaway, PhD, who developed MRV. “Such a dramatic improvement in a critical tool for neuroscience will help researchers illuminate aspects of brain disorders where connectivity and global processing goes awry, such as in autism and schizophrenia.”

“With this new rabies tracer, we can visualize connectivity neuron by neuron, and across long distance input neurons better than with previous rabies tracers,” said lead author Euiseok Kim, PhD, of the Salk systems neurobiology laboratories. “Although this improved version is much better, there are still opportunities to improve the rabies tracer further as we continue to examine other rabies strains.”

The MRV system, developed in 2007 and refined by Professor Callaway and other researchers for targeting specific cell types in 2010, uses a modified version of the rabies virus to infect a brain region. When the system is applied in genetic mouse models, researchers can see specifically how sensory, motor, and reward structures in the brain connect to medium spiny neurons (MSNs) in the basal ganglia. There are two major projection cell types in the striatum of neurons that target downstream basal ganglia and have opposing effects on motivated behavior, but the differential innervation of these neuronal subtypes is not well understood.

Related Links:
Salk Institute for Biological Studies

Gold Member
Solid State Kv/Dose Multi-Sensor
AGMS-DM+
Gold Member
Radiation QA Tool
Accu-Gold 3
New
Portable X-Ray Unit
AJEX240H
Under Table Shield
3 Section Double Pivot Under Table Shield

Print article

Channels

Ultrasound

view channel
Image: Structure of the proposed transparent ultrasound transducer and its optical transmittance (Photo courtesy of POSTECH)

Ultrasensitive Broadband Transparent Ultrasound Transducer Enhances Medical Diagnosis

The ultrasound-photoacoustic dual-modal imaging system combines molecular imaging contrast with ultrasound imaging. It can display molecular and structural details inside the body in real time without... Read more

Imaging IT

view channel
Image: The new Medical Imaging Suite makes healthcare imaging data more accessible, interoperable and useful (Photo courtesy of Google Cloud)

New Google Cloud Medical Imaging Suite Makes Imaging Healthcare Data More Accessible

Medical imaging is a critical tool used to diagnose patients, and there are billions of medical images scanned globally each year. Imaging data accounts for about 90% of all healthcare data1 and, until... Read more

Industry News

view channel
Image: The acquisition will expand IBA’s medical imaging quality assurance offering (Photo courtesy of Radcal)

IBA Acquires Radcal to Expand Medical Imaging Quality Assurance Offering

Ion Beam Applications S.A. (IBA, Louvain-La-Neuve, Belgium), the global leader in particle accelerator technology and a world-leading provider of dosimetry and quality assurance (QA) solutions, has entered... Read more
Copyright © 2000-2024 Globetech Media. All rights reserved.