Amygdala input promotes spread of excitatory neural activity from perirhinal cortex to the entorhinal-hippocampal circuit
Amygdala input promotes spread of excitatory neural activity from perirhinal cortex to the entorhinal-hippocampal circuit
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DOI：
10.1152/jn.01033.2002
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发表时间：
2003-04-01
影响因子：
2.5
通讯作者：
Iijima, T
中科院分区：
文献类型：
--
作者：
Kajiwara, R;Takashima, I;Iijima, T
许多感觉方式最有可能汇聚在大鼠的嗅周皮质。嗅周皮层还与杏仁核相互连接，杏仁核在各种动机和情绪行为中起着重要作用。从嗅周皮层到内嗅皮层的神经通路被认为是进入内嗅海马网络的主要通路之一，内嗅海马网络在记忆过程中起着至关重要的作用。为了研究嗅周皮层对感觉和动机刺激的潜在关联功能以及这种关联对嗅周-内嗅-海马神经回路的影响，我们制备了大鼠脑切片，包括嗅周皮层、内嗅皮层、海马结构和杏仁核。我们使用了一种电压敏感染料的光学成像技术来分析：1）从杏仁核外侧核到嗅周皮层的输入的空间和功能分布; 2）在第II/III层刺激后，嗅周皮层神经活动的传播，这模拟了对嗅周皮层的感觉输入;（3）杏仁外侧核和嗅周皮层第II/III层的联合输入对嗅周-内嗅-海马神经回路的影响。在嗅周皮层的浅层中刺激之后，当在嗅周区域35的深层中发生足够的激活时，电活动仅传播到内嗅皮层中。我们观察到，对嗅周皮层或杏仁核的单一刺激不会导致区域35的深层的足够的神经激活，以引起活动传播到内嗅皮层。然而，当两种刺激同时施加时，35区的深层去极化更强烈，导致内嗅皮层的扩散激活。我们的观察结果表明，高阶感觉输入和情绪相关输入的关联的功能神经基础存在于嗅周皮层，感觉信息传递到内鼻-海马回路可能会受到来自杏仁核的信息的关联的影响。
A number of sensory modalities most likely converge in the rat perirhinal cortex. The perirhinal cortex also interconnects with the amygdala, which plays an important role in various motivational and emotional behaviors. The neural pathway from the perirhinal cortex to the entorhinal cortex is considered one of the main paths into the entorhinal hippocampal network, which has a crucial role in memory processes. To investigate the potential associative function of the perirhinal cortex with respect to sensory and motivational stimuli and the influence of the association on the perirhinal-entorhinal-hippocampal neurocircuit, we prepared rat brain slices including the perirhinal cortex, entorhinal cortex, hippocampal formation, and amygdala. We used an optical imaging technique with a voltage-sensitive dye to analyze 1) the spatial and functional distribution of inputs from the lateral nucleus of the amygdala to the perirhinal cortex; 2) the spread of neural activity in the perirhinal cortex after layers II/III stimulation, which mimics sensory input to the perirhinal cortex; and 3) the effect of associative inputs to the perirhinal cortex from both the lateral amygdaloid nucleus and layers II/III of the perirhinal cortex on the perirhinal-entorhinal-hippocampal neurocircuit. Following stimulation in the superficial layers of the perirhinal cortex, electrical activity only propagated into the entorhinal cortex when sufficient activation occurred in the deep layers of perirhinal area 35. We observed that single stimulation of either the perirhinal cortex or amygdala did not result in sufficient neural activation of the deep layers of areas 35 to provoke activity propagation into the entorhinal cortex. However, the deep layers of area 35 were depolarized much more strongly when the two stimuli were applied simultaneously, resulting in spreading activation in the entorhinal cortex. Our observations suggest that a functional neural basis for the association of higher-order sensory inputs and emotion-related inputs exists in the perirhinal cortex and that transfer of sensory information to the entorhinal-hippocampal circuitry might be affected by the association of that information with incoming information from the amygdala.