Perforant pathway stimulation as a conditioned stimulus for active avoidance learning triggers BOLD responses in various target regions of the hippocampus: A combined fMRI and electrophysiological study
Perforant pathway stimulation as a conditioned stimulus for active avoidance learning triggers BOLD responses in various target regions of the hippocampus: A combined fMRI and electrophysiological study
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DOI：
10.1016/j.neuroimage.2013.03.007
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发表时间：
2013-07-15
期刊：
影响因子：
5.7
通讯作者：
Scheich, Henning
中科院分区：
文献类型：
--
作者：
Angenstein, Frank;Krautwald, Karla;Scheich, Henning
功能磁共振成像和电生理学相结合，监测血氧水平依赖（BOLD）信号在整个大鼠大脑和神经元活动的齿状回在电刺激的右穿通路。在未处理的美托咪定镇静动物中，用15串刺激纤维束（即，以10 ms间隔给予8串20个脉冲，每秒1串，脉冲宽度0.2 ms）在右侧海马结构和左侧内嗅皮质中产生显著的BOLD反应。刺激条件还导致穿孔通路颗粒细胞突触的突触功效发生变化，并持续至少一天。一天后重新进行相同的实验，导致齿状回的电生理反应显著增加，整个海马结构的BOLD反应增加。因此，突触功效的长期变化沿着产生的BOLD反应的变化。在两个fMRI实验之间的清醒动物中的穿通通路的额外电刺激在第二fMRI测量中引起海马结构中的BOLD响应增加，并且在海马的目标区域中出现显著的BOLD响应，例如隔，NAcc（NAcc）和前扣带皮层/内侧前额叶皮层/运动皮层（ACC/mPFC/MC）区域。因此，可以通过海马的目标区域中的BOLD响应的变化来监测海马中的信号处理和通过海马的传播的功效。使用电穿孔通路刺激作为条件刺激的主动回避任务（穿梭箱）引起的BOLD反应在海马结构，隔和ACC/mPFC/MC，但不是在NAcc的进一步蔓延。此外，在训练的动物的BOLD反应的幅度进一步增加，在右侧和左侧海马和ACC/mPFC/MC区，但不是在隔。这些结果表明，除了一般的刺激参数的行为相关性的刺激控制所产生的BOLD响应的质量。(C)2013 Elsevier Inc. All rights reserved.
Functional magnetic resonance imaging and electrophysiology were combined to monitor blood oxygen level dependent (BOLD) signals in the entire rat brain and neuronal activities in the dentate gyrus during electrical stimulation of the right perforant pathway. In naive, medetomidine sedated animals, stimulation of the fiber bundle with 15 trains (i.e. 8 bursts of 20 pulses given with 10 ms intervals, one burst per second, pulse width 0.2 ms) generated significant BOLD responses in the right hippocampal formation and the left entorhinal cortex. The stimulation condition also caused changes in the synaptic efficacy of perforant pathway granular cell synapses that lasted for at least one day. Rerun of the same experiment one day later resulted in a significantly increased electrophysiological response in the dentate gyrus and an increase of the BOLD response in the entire hippocampal formation. Consequently, long-lasting changes in synaptic efficacy go along with changes in the generated BOLD response. Additional electrical stimulations of the perforant pathway in the awake animal between the two fMRI experiments caused in the second fMRI measurement an increased BOLD response in the hippocampal formation and an appearance of significant BOLD responses in target regions of the hippocampus, such as the septum, nucleus accumbens (NAcc), and anterior cingulate cortex/medial prefrontal cortex/motor cortex (ACC/mPFC/MC) regions. Consequently, the efficacy of signal processing in and propagation through the hippocampus can be monitored by variations of the BOLD response in target regions of the hippocampus. Using the electrical perforant pathway stimulations as conditioned stimulus for an active avoidance task (shuttle box) caused a further spreading of the BOLD response in the hippocampus formation, septum and ACC/mPFC/MC but not in the NAcc. In addition, the magnitude of the BOLD response in the trained animals was further increased in the right and left hippocampus and the ACC/mPFC/MC region but not in the septum. These results demonstrate that in addition to general stimulus parameter the behavioral relevance of the stimulus controls the quality of the generated BOLD response. (C) 2013 Elsevier Inc. All rights reserved.