Impact Factor

Original Research ARTICLE

Front. Neuroanat., 19 January 2009 | http://dx.doi.org/10.3389/neuro.05.001.2009

Dual transneuronal tracing in the rat entorhinal-hippocampal circuit by intracerebral injection of recombinant rabies virus vectors

Division of Systems Neuroscience, Tohoku University Graduate School of Life Sciences, Tohoku, Japan
Kavli Institute for Systems Neuroscience and Centre for the Biology of Memory, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
Department of Anatomy and Neurosciences, VU University Medical Center, Amsterdam, The Netherlands
Dual transneuronal tracing is a novel viral tracing methodology which employs two recombinant viruses, each expressing a different reporter protein. Peripheral injection of recombinant pseudorabies viruses has been used as a powerful method to define neurons that coordinate outputs to various peripheral targets of motor and autonomic systems. Here, we assessed the feasibility of recombinants of rabies virus (RV) vector for dual transneuronal tracing in the central nervous system. First, we examined whether two different RV-vectors can double label cells in vitro, and showed that efficient double labeling can be realized by infecting targeted cells with the two RV-vectors within a short time interval. The potential of dual transneuronal tracing was then examined in vivo in the entorhinal-hippocampal circuit, using the chain of projections from CA3 pyramidal cells to CA1 pyramidal cells and subsequently to entorhinal cortex. Six days after the injection of two RV-vectors into the left and right entorhinal cortex respectively, double-labeled neurons were observed in CA3 bilaterally. Some double-labeled neurons showed a Golgi-like labeling. Dual transneuronal tracing potentially provides a powerful and sensitive method to study issues such as the amount of convergence and divergence within and between circuits in the central nervous system. Using this sensitive technique, we established that single neurons in CA3 are connected to the entorhinal cortex bilaterally with only one synaptic relay.
rabies virus vector, double labeling, retrograde transneuronal tracing, hippocampus, entorhinal cortex, CA3 pyramidal cells
Ohara S, Inoue K, Yamada M, Yamawaki T, Koganezawa N, Tsutsui K I, Witter MP and Iijima T (2009). Dual transneuronal tracing in the rat entorhinal-hippocampal circuit by intracerebral injection of recombinant rabies virus vectors. Front. Neuroanat. 3:1. doi: 10.3389/neuro.05.001.2009
18 November 2008;
 Paper pending published:
07 December 2008;
07 January 2009;
 Published online:
19 January 2009.

Edited by:

Kathleen S. Rockland, RIKEN Brain Science Institute, Japan

Reviewed by:

Akiya Watakabe, National Institute for Basic Biology, Japan
Attila I. Gulyas, Hungarian Academy of Sciences, Hungary
© 2009 Ohara, Inoue, Yamada, Yamawaki, Koganezawa, Tsutsui, Witter and Iijima. This is an open-access article subject to an exclusive license agreement between the authors and the Frontiers Research Foundation, which permits unrestricted use, distribution and reproduction in any medium, provided the original authors and source are credited.
Toshio Iijima, Division of Systems Neuroscience, Department of Developmental Biology and Neurosciences, Tohoku University Graduate School of Life Sciences, Sendai, 980-8577, Japan. e-mail: t-iijima@mail.tains.tohoku.ac.jp