A DTI Tractography analysis of Infralimbic and Prelimbic Connectivity in the Mouse using High-throughput MRI

• Type of Material: Article
• Authors: David Andrew Gutman, Emory University; Orion P. Keifer, Emory University; Matthew Magnuson, Emory University; Dennis Clarence Choi, Emory University; Waqas Majeed, Emory University; Shella D Keilholz, Emory University; Kerry J. Ressler, Emory University
• Language: English
• Date: 2012-11-01
• Publisher: Elsevier
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2012 Elsevier Inc. All rights reserved.
• License: Creative Commons Attribution-NonCommerical-NoDerivs 3.0 Unported
• Final Published Version (URL): http://dx.doi.org/10.1016/j.neuroimage.2012.07.014
• Title of Journal or Parent Work: NeuroImage
• ISSN: 1053-8119
• Volume: 63
• Issue: 2
• Start Page: 800
• End Page: 811
• Grant/Funding Information: Support was also provided by the National Institutes of Health (MH071537, DA019624), the Burroughs Wellcome Fund and the National Primate Research Center base grant #RR-00165.; Funding for this project was provided by two Venture Grants from the Science and Technology Center (The Center for Behavioral Neuroscience of the National Science Foundation under Agreement No. IBN-9876754).
• Keywords: Mouse; Infralimbic/Prelimbic; Amygdala; Diffusion Tensor Imaging (DTI); Prefrontal Cortex
• Research Categories: Engineering, Biomedical; Biology, Neuroscience

Abstract

Background High throughput, brain-wide analysis of neural circuit connectivity is needed to understand brain function across species. Combining such tractography techniques with small animal models will allow more rapid integration of systems neuroscience with molecular genetic, behavioral, and cellular approaches. Methods We collected DTI and T2 scans on 3 series of 6 fixed mouse brains ex vivo in a 9.4 Tesla magnet. The DTI analysis of ten mouse brains focused on comparing prelimbic (PL) and Infralimbic (IL) probabilistic tractography. To validate the DTI results a preliminary set of 24 additional mice were injected with BDA into the IL and PL. The DTI results and preliminary BDA results were also compared to previously published rat connectivity. Results We focused our analyses on the connectivity of the mouse prelimbic (PL) vs. infralimbic (IL) cortices. We demonstrated that this DTI analysis is consistent across scanned mice, with prior analyses of rat IL/PL connectivity, and with mouse PL and IL projections using the BDA tracer. Conclusions High-throughput ex vivo DTI imaging in the mouse delineated both common and differential connectivity of the IL and PL cortex. The scanning methodology provided a balance of tissue contrast, signal-to-noise ratio, resolution and throughput. Our results are largely consistent with previously published anterograde staining techniques in rats, and the preliminary tracer study of the mouse IL and PL provided here.