GABAergic transmission in the rat ventral pallidum mediates a saccharin palatability shift in conditioned taste aversion
GABAergic transmission in the rat ventral pallidum mediates a saccharin palatability shift in conditioned taste aversion
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DOI：
10.1111/j.1460-9568.2009.06800.x
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发表时间：
2009-07-01
影响因子：
3.4
通讯作者：
Shimura, Tsuyoshi
中科院分区：
文献类型：
--
作者：
Inui, Tadashi;Yamamoto, Takashi;Shimura, Tsuyoshi
我们之前发现，在条件性味觉厌恶（CTA）建立后，腹侧苍白球（VP）中的γ-氨基丁酸（GABA）（A）受体的阻断会改变条件性刺激（CS）的味觉适口性，从厌恶变为摄入。因为这些结果表明 VP 中的 GABA 能传递介导了 CTA 中味道的适口性降低，本研究旨在使用体内微透析检查味觉刺激对 VP 中 GABA 细胞外释放的影响。最初，大鼠接受配对的 5 mm 糖精或 0.3 mm 奎宁溶液，并腹膜内注射 0.15 m 氯化锂（S-CTA 和 Q-CTA 组）或盐水（S-对照组和 Q-对照组）。经过调节后，在通过口腔内插管引入 CS 之前、期间和之后进行微透析。我们测量了对 CS 的第一次厌恶性口面部反应的潜伏期作为行为指标。在快速拒绝CS（100秒内）的S-CTA组中，GABA外流显着增加（147%）并维持2小时。另一方面，S 对照组没有表现出厌恶反应，并且 GABA 流出没有显着变化。尽管 Q-CTA 组立即表达了对 CS 的厌恶反应（30 秒内），但 GABA 的释放并未因 CS 的出现而改变，这在 Q 对照组中是相似的。这些发现表明，在对糖精而非奎宁的条件性厌恶中，适口性从摄入到厌恶的转变是由 VP 中 GABA 能传递的变化介导的。
We previously found that the blockade of gamma-aminobutyric acid (GABA)(A) receptors in the ventral pallidum (VP) alters the taste palatability of a conditioned stimulus (CS) from aversive to ingestive after the establishment of conditioned taste aversion (CTA). Because these results suggest that GABAergic transmission in the VP mediates decreased palatability of the taste in CTA, the present study aimed to examine the effects of taste stimulation on the extracellular release of GABA in the VP using in vivo microdialysis. Initially, rats received a paired presentation of 5 mm saccharin or 0.3 mm quinine solution with an intraperitoneal injection of 0.15 m lithium chloride (S-CTA and Q-CTA groups) or saline (S-control and Q-control groups). After conditioning, microdialysis was carried out before, during and after the presentation of the CS via an intra-oral cannula. We measured the latency of the first aversive orofacial responses to the CS as behavioral indices. In the S-CTA group, which rapidly rejected the CS (within 100 s), the GABA efflux was significantly increased (147%) and was maintained for 2 h. On the other hand, the S-control group expressed no aversive responses and showed no significant alterations in GABA efflux. Although the Q-CTA group immediately expressed aversive responses to the CS (within 30 s), GABA release was not changed by presentation of the CS, which was similar in the Q-control group. These findings suggest that the palatability shift from ingestive to aversive in conditioned aversion to saccharin, but not quinine, is mediated by the change in GABAergic transmission in the VP.