Spatiotemporal dynamics of long-term potentiation in rat insular cortex revealed by optical imaging
Spatiotemporal dynamics of long-term potentiation in rat insular cortex revealed by optical imaging
复制标题
DOI：
10.1016/j.nlm.2011.07.003
复制
发表时间：
2011-10-01
影响因子：
2.7
通讯作者：
Kobayashi, Masayuki
中科院分区：
文献类型：
--
作者：
Mizoguchi, Naoko;Fujita, Satoshi;Kobayashi, Masayuki
味觉皮层（GC）的长时程增强（LIP）是大脑中动脉周围岛叶皮层（IC）的一部分，是味觉学习和记忆的关键过程，包括条件性味觉厌恶学习。吻侧（rGC）和尾侧（cGC）处理不同的味觉：前侧（rGC）响应享乐的味觉，后侧（cGC）响应厌恶的味觉。然而，rGC和cGC之间兴奋性传播空间相互作用的塑性变化尚不清楚。本研究旨在利用电压敏感染料的体内光学成像技术，阐明电刺激rGC/cGC在LIP诱导前后的兴奋性传播的时空特征。结果表明，在五列刺激下，强直性刺激会导致cGC的兴奋持续扩大，并且IC中的光信号幅度增加。LIP诱导后的兴奋传播优先向吻侧IC传播：通过单指数曲线拟合光信号获得的兴奋长度常数(A)在吻侧方向增加到121.9%，而)。尾端、背侧和腹侧分别为48.9%、44.2%和62.5%。通过在皮质表面预先应用D-APV（一种NMDA受体拮抗剂）或阿托品（一种毒碱受体拮抗剂）来阻止LIP的诱导。相比之下，rGC刺激仅引起轻微的LIP，无方向偏好。考虑到rGC和cGC在味觉加工中的不同作用，GC中LIP的这些特征模式可能与适口性转化的机制有关。(C) 2011爱思唯尔公司版权所有。
Long-term potentiation (LIP) of the gustatory cortex (GC), a part of the insular cortex (IC) around the middle cerebral artery, is a key process of gustatory learning and memory, including conditioned taste aversion learning. The rostral (rGC) and caudal GC (cGC) process different tastes: the rGC responds to hedonic and the cGC responds to aversive tastes. However, plastic changes of spatial interaction of excitatory propagation between the rGC and cGC remain unknown. The present study aimed to elucidate spatiotemporal profiles of excitatory propagation, induced by electrical stimulation (five train pulses) of the rGC/cGC before and after LIP induction, using in vivo optical imaging with a voltage-sensitive dye. We demonstrated that tetanic stimulation of the cGC induced long-lasting expansion of the excitation responding to five train stimulation of the cGC, and an increase in amplitude of optical signals in the IC. Excitatory propagation after LIP induction spread preferentially toward the rostral IC: the length constant (A) of excitation, obtained by fitting optical signals with a monoexponential curve, was increased to 121.9% in the rostral direction, whereas). for the caudal, dorsal, and ventral directions were 48.9%, 44.2%, and 62.5%, respectively. LIP induction was prevented by pre-application of D-APV, an NMDA receptor antagonist, or atropine, a muscarinic receptor antagonist, to the cortical surface. In contrast, rGC stimulation induced only slight LIP without direction preference. Considering the different roles of the rGC and cGC in gustatory processing, these characteristic patterns of LIP in the GC may be involved in a mechanism underlying conversion of palatability. (C) 2011 Elsevier Inc. All rights reserved.