Network Plasticity Involved in the Spread of Neural Activity Within the Rhinal Cortices as Revealed by Voltage-Sensitive Dye Imaging in Mouse Brain Slices
Network Plasticity Involved in the Spread of Neural Activity Within the Rhinal Cortices as Revealed by Voltage-Sensitive Dye Imaging in Mouse Brain Slices
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DOI：
10.3389/fncel.2019.00020
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发表时间：
2019-02-06
影响因子：
5.3
通讯作者：
Tominaga, Takashi
中科院分区：
文献类型：
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作者：
Kajiwara, Riichi;Tominaga, Yoko;Tominaga, Takashi
鼻腔皮质，如嗅周皮质（perirhinal cortex，PC）和内嗅皮质（entorhinal cortex，EC），位于新皮质和海马之间的双向通路内。生理学研究表明，新皮层输入到EC的嗅周传递发生在一个非常低的概率，虽然许多解剖学研究表明，强大的连接存在于该途径。我们以前在大鼠脑片的研究表明，在PC/EC边界的深层兴奋性的增加启动了从PC到EC的神经活动转移。在本研究中，我们假设这种网络动态的变化不是偶然的观察，而是由于与EC联系的围鼻网络的塑性特征。为了证实这一想法，我们分析了整个鼻腔皮质的神经传输网络的属性和网络的可塑性行为，通过执行单光子宽场光学记录技术与电压敏感染料（VSD）在小鼠脑切片的PC，EC和海马。低浓度的4-氨基吡啶（4-AP; 40 μ M）增强PC中的神经活动，最终通过PC/EC边界的深层传播到EC。有趣的是，4-AP的洗脱不能将内嗅激活逆转到先前的状态。网络属性的这种变化持续超过1小时。该观察结果并不限于4-AP的应用。对嗅周深层神经元的猝发刺激也引起了同样的网络性质的变化。这些结果表明，PC和EC之间的生理连接的长期持久的修改，这表明存在的可塑性在鼻周-内嗅网络。
The rhinal cortices, such as the perirhinal cortex (PC) and the entorhinal cortex (EC), are located within the bidirectional pathway between the neocortex and the hippocampus. Physiological studies indicate that the perirhinal transmission of neocortical inputs to the EC occurs at an extremely low probability, though many anatomical studies indicated strong connections exist in the pathway. Our previous study in rat brain slices indicated that an increase in excitability in deep layers of the PC/EC border initiated the neural activity transfer from the PC to the EC. In the present study, we hypothesized that such changes in network dynamics are not incidental observations but rather due to the plastic features of the perirhinal network, which links with the EC. To confirm this idea, we analyzed the network properties of neural transmission throughout the rhinal cortices and the plastic behavior of the network by performing a single-photon wide-field optical recording technique with a voltage-sensitive dye (VSD) in mouse brain slices of the PC, the EC, and the hippocampus. The low concentration of 4-aminopyridine (4-AP; 40 mu M) enhanced neural activity in the PC, which eventually propagated to the EC via the deep layers of the PC/EC border. Interestingly, washout of 4-AP was unable to reverse entorhinal activation to the previous state. This change in the network property persisted for more than 1 h. This observation was not limited to the application of 4-AP. Burst stimulation to neurons in the perirhinal deep layers also induced the same change of network property. These results indicate the long-lasting modification of physiological connection between the PC and the EC, suggesting the existence of plasticity in the perirhinal-entorhinal network.