A DTI tractography analysis of infralimbic and prelimbic connectivity in the mouse using high-throughput MRI.
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.
Department of Biomedical Informatics, Emory University, USA.
David A
DA
Gutman
Orion P
OP
Keifer
Matthew E
ME
Magnuson
Dennis C
DC
Choi
Waqas
W
Majeed
Shella
S
Keilholz
Kerry J
KJ
Ressler
D000818:Animals; D001921:Brain / Q000033:anatomy & histology*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D057166:High-Throughput Screening Assays; D007091:Image Processing, Computer-Assisted; D051379:Mice; D008810:Mice, Inbred C57BL; D009434:Neural Pathways / Q000033:anatomy & histology*