Synchronized electrical stimulation of the rat medial forebrain bundle and perforant pathway generates an additive BOLD response in the nucleus accumbens and prefrontal cortex
Synchronized electrical stimulation of the rat medial forebrain bundle and perforant pathway generates an additive BOLD response in the nucleus accumbens and prefrontal cortex
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DOI：
10.1016/j.neuroimage.2013.03.046
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发表时间：
2013-08-15
期刊：
影响因子：
5.7
通讯作者：
Angenstein, Frank
中科院分区：
文献类型：
--
作者：
Krautwald, Karla;Min, Hoon-Ki;Angenstein, Frank
为了研究两条独立通路的同步激活如何影响共同靶区的fMRI反应，我们测量了电刺激右侧内侧前脑束(MFB)、右侧穿支通路(PP)和同时刺激两个纤维系统时的血氧依赖(BOLD)信号。重复电刺激MFB可在伏核(NAcc)、隔核、扣带回前皮质/前额内侧皮质(Acc/mPFC)、腹侧被盖区/黑质(VTA/SN)、右侧内嗅皮层(EC)和上丘引起显著的阳性BOLD反应。同时，在纹状体也观察到了否定的大胆反应。因此，相同的刺激会引起特定区域的血流动力学反应。相同的电刺激PP在右侧齿状回/海马体/下丘(DG/HC)、右侧内嗅皮质和左侧内嗅皮质产生阳性的BOLD反应，在连续的刺激序列中几乎保持稳定。两个纤维系统的共同刺激导致一种相加的激活模式，即刺激两个通路时的BOLD反应比单独刺激一个通路时的BOLD反应更强。然而，在两个通道的同时刺激期间，对连续列车的大胆反应的发展发生了变化。在刺激MFB主要激活的区域(即NAcc、间隔和ACC/mPFC)，BOLD反应的下降速度没有单纯刺激MFB时那么快，因此只有在较晚的训练中才能观察到相加的BOLD反应。相反，在主要由PP刺激激活的脑区(即右EC、DG/HC)，联合刺激MFB只在早期训练中产生相加效应，而在后期训练中没有。因此，在连续刺激过程中，大胆反应的发展表明在目标区域的两个通路之间存在相互作用，而观察到的平均大胆反应没有。(C)2013 Elsevier Inc.保留所有权利。
To study how a synchronized activation of two independent pathways affects the fMRI response in a common targeted brain region, blood oxygen dependent (BOLD) signals were measured during electrical stimulation of the right medial forebrain bundle (MFB), the right perforant pathway (PP) and concurrent stimulation of the two fiber systems. Repetitive electrical stimulations of the MFB triggered significant positive BOLD responses in the nucleus accumbens (NAcc), septum, anterior cingulate cortex/medial prefrontal cortex (ACC/mPFC), ventral tegmental area/substantia nigra (VTA/SN), right entorhinal cortex (EC) and colliculus superior, which, in general, declined during later stimulation trains. At the same time, negative BOLD responses were observed in the striatum. Thus, the same stimulus caused region-specific hemodynamic responses. An identical electrical stimulation of the PP generated positive BOLD responses in the right dentate gyrus/hippocampus proper/subiculum (DG/HC), the right entorhinal cortex and the left entorhinal cortex, which remained almost stable during consecutive stimulation trains. Co-stimulation of the two fiber systems resulted in an additive activation pattern, i.e., the BOLD responses were stronger during the stimulation of the two pathways than during the stimulation of only one pathway. However, during the simultaneous stimulation of the two pathways, the development of the BOLD responses to consecutive trains changed. The BOLD responses in regions that were predominantly activated by MFB stimulation (i.e., NAcc, septum and ACC/mPFC) did not decline as fast as during pure MFB stimulation, thus an additive BOLD response was only observed during later trains. In contrast, in the brain regions that were predominantly activated by PP stimulation (i.e., right EC, DG/HC), co-stimulation of the MFB only resulted in an additive effect during early trains but not later trains. Consequently, the development of the BOLD responses during consecutive stimulations indicates the presence of an interaction between the two pathways in a target region, whereas the observed averaged BOLD responses do not. (C) 2013 Elsevier Inc. All rights reserved.