Activation and habituation in olfaction - An fMRI study
Activation and habituation in olfaction - An fMRI study
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DOI：
10.1006/nimg.2000.0713
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发表时间：
2001-04-01
期刊：
影响因子：
5.7
通讯作者：
Kwong, KK
中科院分区：
文献类型：
--
作者：
Poellinger, A;Thomas, R;Kwong, KK
本研究采用3-T MR扫描仪研究了人类初级和高级嗅觉皮层在短时间和长时间气味刺激后的BOLD反应。其目的是确定反应过程中可能导致习惯化的时间差异。一个短时间的刺激（9秒）始终激活初级嗅觉皮层（POC）。长时间刺激（60 s）后，嗅觉网络不同部分的反应时间形式不同：（1）POC（梨状核，内嗅皮层，杏仁核），有趣的是，海马，在一定程度上，前额叶的信号显示出短暂的阶段性增加，随后是低于基线的长期下降。(2)在眶额皮质中，观察到激活的持续增加，这种增加持续大约与气味呈现的持续时间一样长（类似于60 s）。(3)丘脑背内侧核和尾状核的信号增加，约15至30秒后恢复到基线。相关的双相血流动力学反应在POC，海马，和前额叶在长时间的嗅觉刺激表明，这三个领域可能相互密切联系，在控制习惯化。这些结果扩展了最近的数据，表明大鼠梨状皮质的习惯化和分离之间的POC和眶额皮质。(C)北京：科学出版社.
This study investigated human BOLD responses in primary and higher order olfactory cortices following presentation of short- and long duration odorant stimuli using a 3-T MR scanner. The goal was to identify temporal differences in the course of the response that might underlie habituation. A short-duration stimulus (9 s) consistently activated the primary olfactory cortex (POC). After a long stimulus (60 s), the temporal form of the response differed in different parts of the olfactory network: (1) The POC (piriform, entorhinal cortex, amygdala) and, interestingly, the hippocampus and, to a certain degree, the anterior insula show a short, phasic increase in the signal, followed by a prolonged decrease below baseline. (2) In the orbitofrontal cortex a sustained increase in activation was seen, This increase lasted approximately as long as the duration of odorant presentation (similar to 60 s). (3) The mediodorsal nucleus of the thalamus and the caudate nucleus responded with an increase in signal which returned to baseline after approximately 15 to 30 s. The correlated biphasic hemodynamic response in the POC, hippocampus, and anterior insula during prolonged olfactory stimulation suggests that these three areas may interact closely with each other in the control of habituation. These results extend recent data which showed habituation of the rat piriform cortex and dissociation between the POC and the orbitofrontal cortex. (C) 2001 Academic Press.