Neuroscience 2003 Abstract
| Presentation Number: | 21.4 |
|---|---|
| Abstract Title: | Statistical mapping of functional olfactory connections in the rat brain <I>in vivo</I>. |
| Authors: |
Cross, D. J.*1
; Anzai, Y.1
; Maravilla, K. R.1
; Morrow, T. J.
; Flexman, J. A.2
; Miyoshi, S.2
; Minoshima, S.1,2
1Dept. of Radiology, U. of Washington, Seattle, WA 2Dept. of BioEngin., U. of Washington, Seattle, WA |
| Primary Theme and Topics |
Techniques in Neuroscience - Staining, tracing and imaging techniques |
| Secondary Theme and Topics | Sensory Systems<br />- Chemical senses<br />-- Olfaction: CNS pathways and physiology |
| Session: |
21. Staining, Tracing & Imaging Techniques I Slide |
| Presentation Time: | Saturday, November 8, 2003 1:45 PM-1:45 PM |
| Location: | Morial Convention Center - Room 398 |
| Keywords: | MRI, Brain Mapping, Drug Delivery |
The olfactory system is indicated as a route for drug delivery to the brain. The study was conducted to map functional connections of the olfactory system in vivo using magnetic resonance imaging (MRI) and manganese as a transport-mediated tracer. Six male rats were imaged by 1.5T MRI with a bird-cage coil and 3D-SPGR pulse sequence at pre-injection, and 24, 36, 48, and 72 hours post injection of MnCl2 into the right nasal cavity. Images were coregistered, pixel-intensity normalized, and stereotactically transformed to a rat brain atlas, then averaged across subjects using fully automated image analysis software (NEUROSTAT). Images at each time were compared to pre-injection using a one-sample t-statistic on a pixel-by-pixel basis in 3-D and converted to Z maps. Identical imaging was done in a rat after stereotaxic radiofrequency lesioning of the lateral olfactory tract (LOT) at +2.2 mm anterior to Bregma (b.). Significant transport of Mn was observed in the bulb bilaterally (z=39.8 for ipsilateral (ip.) to injection and 18.3 for contralateral (c.), respectively), ip. anterior LOT (b. +3.20, z=15.8), ip. nucleus accumbens (z=9.8), ip. anterior commissure (AC) (z=8.5) and ip. posterior LOT (b. –0.40, z=10.5) by 24 hours; ip. anterior piriform cortex (b. +3.20) and ip. ventral pallidum (z=4.8) by 36 hrs; entire AC (z=6.4), ip. amygdala(z=4.7), and ip. posterior piriform cortex (b. -6.04, z=5.3) by 48 hrs; and ip. caudate (z=4.4) and ip. hypothalamus (z=2.6) by 72 hours, including enhancement in pathways connecting these structures. Lesioning disrupted transport (30% vs. 2% signal change in LOT rostral and caudal to lesion, respectively), indicating distal enhancement was not due to tracer diffusion from plasma. The study showed widespread functional connections of the olfactory system that may serve as a unique molecular delivery system.
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2003 Neuroscience Meeting Planner. New Orleans, LA: Society for Neuroscience, 2003. Online.
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