Neuroscience 2003 Abstract
| Presentation Number: | 913.4 |
|---|---|
| Abstract Title: | Olfactory tract tracing in rats by manganese-enhanced magnetic resonance imaging. |
| Authors: |
Kondoh, T.*1
; Shibata, R.1
; Uneyama, H.1
; Torii, K.1
1Inst. of Life Sci., Ajinomoto Co., Inc., Kawasaki, Japan |
| Primary Theme and Topics |
Sensory Systems - Chemical senses -- Olfaction: CNS pathways and physiology |
| Session: |
913. Olfaction: Higher-order CNS Pathways, Behavior, & Clinical Issues Poster |
| Presentation Time: | Wednesday, November 12, 2003 4:00 PM-5:00 PM |
| Location: | Morial Convention Center - Hall F-I, Board # F24 |
| Keywords: | OLFACTION, OLFACTORY BULB, AMYGDALA, MRI |
Our previous study using functional magnetic resonance imaging (MRI) suggests that the medial prefrontal cortex (mPFC), which is not considered as one of the olfactory centers, responded well to olfactory stimulations similar to the ventrolateral primary olfactory cortex (i.e., the piriform cortex and olfactory tubercle). The present study was aimed to investigate neural projections from olfactory cortices to mPFC by using manganese-enhanced MRI (MEMRI), a newly developed in vivo neural tracing technique. Rats were anesthetized and MnCl2 (100 mM, 0.2-0.5 μl) was injected stereotaxically by using a glass micropipette into several parts of olfactory pathway. Injection of Mn2+, a biological calcium analogue and paramagnetic tract tracing agent, allows highlighting specific brain areas that are active. T1-weighted multislice spin-echo images were acquired at 8 h and 24 h after Mn2+ injection using SMIS MRI system, consisted of a 4.7 T/400 horizontal superconducting magnet equipped with actively shielded gradient coils (54 mT/m, 26-cm i.d.). Injection of Mn2+ into the olfactory bulb clearly enhanced T1-weighted signals in the anterior olfactory nucleus, lateral olfactory tract, piriform cortex, and orbital cortex but not in the mPFC. Injection of Mn2+ into the lateral olfactory tract enhanced the signals in the olfactory bulb, anterior olfactory nucleus, the lateral entorhinal cortex, the lateral hypothalamic area, and substantia nigra but not in the mPFC. Signals in the mPFC were enhanced by injection of Mn2+ into the amydgala, the mediodorsal hypothalamic nucleus, or CA1 of the hippocampus. These results suggest that the mPFC receives olfactory inputs from high-order olfactory centers (i.e., the amydgala, the mediodorsal hypothalamic nucleus and the CA1) but not from the olfactory bulb and the ventrolateral primary olfactory cortex. MEMRI is proved to be useful technique to visualize neural connections in the olfactory pathway in rats.
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2003 Neuroscience Meeting Planner. New Orleans, LA: Society for Neuroscience, 2003. Online.
Copyright © 2003-2025 Society for Neuroscience; all rights reserved. Permission to republish any abstract or part of any abstract in any form must be obtained in writing by SfN office prior to publication.
