The added value of rabies virus as a retrograde tracer when combined with dual anterograde tract-tracing.
Rabies virus (RV) has widely been used as a trans-synaptic retrograde tracer to analyze chains of connected neurons. The use of antibodies directed against the viral nucleoprotein enables viral nucleocapsids to be visualized within the cell soma, as well as within the thickest main dendrites. However, through this approach it is often difficult to accurately define post-synaptic elements (thin dendrites and/or dendritic spines). This limitation can now easily been circumvented by taking advantage of antibodies directed against a soluble viral phosphoprotein that spreads throughout the cytoplasm of the infected neuron, thereby producing Golgi-like immunofluorescent labeling of first-order projection neurons that are infected with RV. Furthermore, when combined with anterograde tracers such as Phaseolus vulgaris-leucoagglutinin (PHA-L) and biotinylated dextran amine (BDA), this procedure to detect RV facilitates the accurate visualization of both the pre- and post-synaptic elements. Finally, this method of viral detection is sufficiently sensitive to detect weakly labeled second-order neurons, which can then be further characterized neurochemically. Several examples are provided to illustrate why retrograde trans-synaptic tracing using RV can be regarded as an important breakthrough in the analysis of brain circuits, providing an unprecedented level of resolution.
López
Iciar P
IP
Area de Neurociencias, Centro de Investigación Médica Aplicada (CIMA), Universidad de Navarra and Centro de Investigación en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Pamplona, Spain.
Salin
Pascal
P
Kachidian
Philippe
P
Barroso-Chinea
Pedro
P
Rico
Alberto J
AJ
Gómez-Bautista
Virginia
V
Conte-Perales
Lorena
L
Coulon
Patrice
P
Kerkerian-Le Goff
Lydia
L
Lanciego
José L
JL
D000818:Animals; D000906:Antibodies; D001710:Biotin / Q000031:analogs & derivatives; D002540:Cerebral Cortex / Q000033:anatomy & histology; D003342:Corpus Striatum / Q000033:anatomy & histology; D003911:Dextrans; D005456:Fluorescent Dyes; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D007395:Interneurons / Q000502:physiology; D008297:Male; D018613:Microscopy, Confocal; D009445:Neuroanatomy / Q000379:methods*; D056325:Neuronal Tract-Tracers; D009474:Neurons / Q000502:physiology; D010750:Phosphoproteins / Q000276:immunology; D010835:Phytohemagglutinins; D011820:Rabies virus / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D013569:Synapses / Q000502:physiology
D000906:Antibodies; D003911:Dextrans; D005456:Fluorescent Dyes; D056325:Neuronal Tract-Tracers; D010750:Phosphoproteins; D010835:Phytohemagglutinins; C076397:biotinylated dextran amine; C100156:leukoagglutinins, plants; D001710:Biotin