Manganese-enhanced MRI of layer-specific activity in the visual cortex from awake and free-moving rats.
Manganese-enhanced MRI of layer-specific activity in the visual cortex from awake and free-moving rats.
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DOI：
10.1016/j.neuroimage.2008.10.013
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发表时间：
2009-02-01
期刊：
影响因子：
5.7
通讯作者：
Berkowitz BA
中科院分区：
文献类型：
--
作者：
Bissig D;Berkowitz BA
在啮齿类动物中，对视觉刺激的皮质反应已经进行了广泛的研究，但通常需要在刺激后对组织进行体外检查。在这里，我们测试了这样一个假设，即清醒和自由活动的大鼠的视觉刺激依赖的皮质活动可以在系统注射MnCl2后进行编码，并随后使用锰增强磁共振成像(MEMRI)读出活动，这是一种可以在不牺牲动物的情况下执行的技术。未麻醉的SD大鼠，在全身注射或不全身注射MnCl2的情况下，在视觉刺激环境或黑暗中维持8小时。为了确定皮层活动的视觉依赖性变化，动物被麻醉，并用3D REARE MEMRI检查皮质。比较皮质下区域(如上丘和外侧膝状体)和皮质区域(初级和副视觉皮质)的平均信号强度。大脑皮层线性化以帮助进行特定层面的信号强度比较。单独服用锰会增加大脑中的信号强度(P<；0.0001)。在视觉刺激和未刺激的大鼠中，层特异性分析显示，与暗适应大鼠相比，受刺激的大鼠初级视觉皮质的IV层和V层以及浅上丘深层的信号强度平均显著(P<；0.05)高。如果不进行特定层级的分析，这种差异是不会被发现的。我们首次证明了在清醒和自由活动的大鼠中编码活动后，层特定刺激依赖的非侵入性MEMRI读出的可行性。未来的MEMRI研究将在纵向研究中测量感觉刺激对皮质活动的影响，以及正常发育、疾病、可塑性和治疗。
Cortical responses to visual stimulation have been studied extensively in the rodent, but often require post-stimulation ex vivo examination of the tissue. Here, we test the hypothesis that visual stimulus-dependent cortical activity from awake and free-moving rats can be encoded following systemically administered MnCl2, and activity subsequently readout using manganese-enhanced MRI (MEMRI), a technique that can be performed without sacrificing the animal. Unanaesthetized Sprague–Dawley rats, with or without systemic injection of MnCl2, were maintained for eight hours in either a visually stimulating environment or darkness. To identify vision-dependent changes in cortical activity, animals were anesthetized and cortices were examined by 3D RARE MEMRI. Mean signal intensities in sub-cortical regions (e.g., superior colliculus and the lateral geniculate), and cortical regions (primary and accessory visual cortices) were compared. Cortex linearization was performed to aid in layer-specific signal intensity comparisons. Manganese administration alone globally increased signal intensity in the brain (P < 0.0001). In visually stimulated and unstimulated rats, layer-specific analysis revealed that stimulated rats had on average significantly (P < 0.05) higher signal intensities in layers IV and V of the primary visual cortex, as well as in deeper portions of the superficial superior colliculus, relative to dark adapted rats. Such differences went undetected without layer-specific analysis. We demonstrate, for the first time, the feasibility of layer-specific stimulus-dependant non-invasive MEMRI readout after encoding activity in awake and free moving rats. Future MEMRI studies are envisioned that measure the effects on cortical activity of sensory stimulation, as well as normal development, disease, plasticity, and therapy in longitudinal studies.
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影响因子：
5.7
作者：
Aoki, I;Wu, YJL;Koretsky, AP
通讯作者：
Koretsky, AP
影响因子：
4.4
作者：
Berkowitz, Bruce A.;Roberts, Robin;Vingrys, Algis J.
通讯作者：
Vingrys, Algis J.
影响因子：
4.4
作者：
Berkowitz, Bruce A.;Roberts, Robin;Luan, Hongmei
通讯作者：
Luan, Hongmei
DOI：
10.3109/13813458209070564
发表时间：
1982-01-01
期刊：
ARCHIVES INTERNATIONALES DE PHYSIOLOGIE DE BIOCHIMIE ET DE BIOPHYSIQUE
影响因子：
--
作者：
BIRAL, GP;CAVAZZUTI, M;CORAZZA, R
通讯作者：
CORAZZA, R
影响因子：
5.3
作者：
COOPER, RM;THURLOW, GA
通讯作者：
THURLOW, GA