Chen Wei, Tenney Jeff, Kulkarni Praveen, King Jean A
University of Massachusetts Medical School, Department of Psychiatry, Center for Comparative Neuroimaging, 55 Lake Avenue North, Worcester, MA 01655, USA.
Neuroimage. 2007 Aug 1;37(1):221-9. doi: 10.1016/j.neuroimage.2007.05.001. Epub 2007 May 10.
Recent use of manganese-enhanced MRI (MEMRI) to assess the neural circuitry involved in autonomic and somatosensory paradigms has been promising. The current study addresses the feasibility of utilizing this technique to assess more complex cognitive and emotional processes. Since olfactory cues are particularly salient to animals, we utilized odorless air, novel/arousing and novel/fear-inducing scents to assess the neural circuitry sub-serving novelty and unconditioned fear. The present imaging data clearly indicate that animals with no prior exposure to a threat-inducing emotional stimulus selectively activated the unconditional fear neuronal pathway, specifically with heightened amygdala and hypothalamic activation. While animals exposed to the novel/arousing compared to fear-inducing odor demonstrated enhanced uptake in the cingulated and prefrontal cortices. In addition, as expected the hippocampus showed significantly enhanced manganese contrast after novelty exposure. Therefore the current study support the validity of MEMRI in the exploration of highly relevant complex neural circuitries associated with cognition and emotion.
近期使用锰增强磁共振成像（MEMRI）来评估自主神经和躯体感觉范式中涉及的神经回路已颇具前景。当前研究探讨了利用该技术评估更复杂认知和情感过程的可行性。由于嗅觉线索对动物尤为显著，我们使用无味空气、新奇/刺激性和新奇/诱发恐惧的气味来评估服务于新奇感和无条件恐惧的神经回路。目前的成像数据清楚地表明，之前未接触过诱发威胁性情绪刺激的动物选择性地激活了无条件恐惧神经元通路，特别是杏仁核和下丘脑的激活增强。与诱发恐惧的气味相比，接触新奇/刺激性气味的动物在扣带回和前额叶皮质显示出增强的摄取。此外，正如预期的那样，新奇刺激后海马体的锰对比度显著增强。因此，当前研究支持了MEMRI在探索与认知和情感相关的高度相关复杂神经回路方面的有效性。
