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M. Haberl, S. Viana da Silva, A. Frick et al. in Brain Struct Funct

Un virus mutant de la rage pour l'analyse structurelle et fonctionnelle des circuits neuronaux .

Le 2 mai 2014

An anterograde rabies virus vector for high-resolution large-scale reconstruction of 3D neuron morphology.
Haberl MG, Viana da Silva S, Guest JM, Ginger M, Ghanem A, Mulle C, Oberlaender M, Conzelmann KK, Frick A.
Brain Struct Funct. 2014 Apr 11

This study was supported by LabEx BRAIN
for a total of 200k€ (scientific project axis 2 and PhD extension grant Matthias Haberl


An innovative approach for tracing detailed neuronal morphology on a brain-wide scale

Several high profile brain-mapping projects promise to do for the connectome (the complete map of all synaptic contacts of the entire brain) what the human genome project did for the genome. Connectomics—the study of the connectome—requires a range of innovative methods, including those to label defined neurons within a circuit or brain area and to permit their manipulation, or monitoring of their functional activity. 

Here were present a novel viral method to reveal the detailed morphology of neurons enabling their fine-scale reconstruction on a brain-wide level. To do this, we exploited the capacity of a mutant recombinant vaccine-strain rabies virus to confer intense morphological labeling on target neurons. This virus lacks the capacity to cross synapses. In addition, by ‘repackaging’ the virus with a new envelope protein, we eliminated its ability to infect axon terminals.

The result was an anterograde tracer, which was equally effective for labeling populations of neurons or individual neurons at the site of injection. This tracer can be combined with retrogradely tracing variants for the labeling of reciprocal projections over the same timescales. Moreover, it allows the reconstruction of all key morphological features of neurons: dendrites, spines, boutons, and importantly long-ranging axons extending throughout the brain. We demonstrate its usefulness in a number of experimental questions and brain areas, using proprietary as well as custom-written reconstruction approaches. This tracer has one additional advantage in that it can be used over a wide range of ages/species. Here, for example, we demonstrated its use in an Alzheimer model.

Lastly, the ability of this vector to encode additional transgenes and to rapidly express them at high levels provides an attractive and often superior alternative to lentivirus and adeno-associated virus based expression vectors. This method promises to greatly enhance the toolbox for the structural functional analysis of neuronal circuits. 

 Abstract PuMed

Glycoprotein-deleted rabies virus (RABV ∆G) is a powerful tool for the analysis of neural circuits. Here, we demonstrate the utility of an anterograde RABV ∆G variant for novel neuroanatomical approaches involving either bulk or sparse neuronal populations. This technology exploits the unique features of RABV ∆G vectors, namely autonomous, rapid high-level expression of transgenes, and limited cytotoxicity. Our vector permits the unambiguous long-range and fine-scale tracing of the entire axonal arbor of individual neurons throughout the brain. Notably, this level of labeling can be achieved following infection with a single viral particle. The vector is effective over a range of ages (>14 months) aiding the studies of neurodegenerative disorders or aging, and infects numerous cell types in all brain regions tested. Lastly, it can also be readily combined with retrograde RABV ∆G variants. Together with other modern technologies, this tool provides new possibilities for the investigation of the anatomy and physiology of neural circuits.

http://link.springer.com/article/10.1007%2Fs00429-014-0730-z

Andreas Frick, Group leader (andreas.frick @ inserm.fr)
Dernière mise à jour le 22.05.2014

Authors



Silvia Viana da Silva,
PhD Student CNRS UMR 5297 Interdisciplinary Institute of Neuroscience . Christophe Mulle team.
silviamvsilva@gmail.com


Matthias Haberl,
PhD Student Neurocentre Magendie, INSERM U862 Group "Circuit and dendritic mechanisms underlying cortical plasticity" matthias.haberl@inserm.fr



Andreas Frick,
PhD, Group Leader Neurocentre Magendie, INSERM U862 Group "Circuit and dendritic mechanisms underlying cortical plasticity" andreas.frick@inserm.fr


Andreas Frick Team
Cortical plasticity mechanisms in normal and pathological conditions