Institute of Life Sciences, Ajinomoto Co., Inc., Suzuki-cho 1-1 Kawasaki-ku, Kawasaki 210-8601, Japan.
Neuroscience. 2010 Dec 1;171(2):451-60. doi: 10.1016/j.neuroscience.2010.09.016. Epub 2010 Sep 16.
The brain's response to ethanol intake has been extensively investigated using electrophysiological recordings, brain lesion techniques, and c-Fos immunoreactivity. However, few studies have investigated this phenomenon using functional magnetic resonance imaging (fMRI). In the present study, we used fMRI to investigate the blood oxygenation level-dependent (BOLD) signal response to an intragastric (IG) load of ethanol in conscious, ethanol-naive rats. An intragastrically infused 10% ethanol solution induced a significant decrease in the intensity of the BOLD signal in several regions of the brain, including the bilateral amygdala (AMG), nucleus accumbens (NAc), hippocampus, ventral pallidum, insular cortex, and cingulate cortex, and an increase in the BOLD signal in the ventral tegmental area (VTA) and hypothalamic regions. Treatment with bicuculline, which is an antagonist of the gamma-aminobutyric acid A (GABA(A)) receptor, increased the BOLD signal intensity in the regions that had shown decreases in the BOLD signal after the IG infusion of 10% ethanol solution, but it did not affect the BOLD signal increase in the hypothalamus. Treatment with SCH39166, which is an antagonist of D1-like receptors, eliminated the increase in the BOLD signal intensity in the hypothalamic areas but did not affect the BOLD signal decrease following the 10% ethanol infusion. These results indicate that an IG load of ethanol caused both a GABA(A) receptor-mediated BOLD decrease in the limbic system and the cortex and a D1-like receptor-mediated BOLD increase in the hypothalamic regions in ethanol-naive rats.
大脑对乙醇摄入的反应已经通过电生理学记录、脑损伤技术和 c-Fos 免疫反应性进行了广泛研究。然而，很少有研究使用功能磁共振成像（fMRI）来研究这种现象。在本研究中，我们使用 fMRI 研究了在清醒、未接触乙醇的大鼠中，胃内（IG）乙醇负荷对内源性 BOLD 信号的反应。胃内输注 10%乙醇溶液会导致大脑多个区域的 BOLD 信号强度显著降低，包括双侧杏仁核（AMG）、伏隔核（NAc）、海马体、腹侧苍白球、岛叶皮层和扣带回皮层，以及腹侧被盖区（VTA）和下丘脑区域的 BOLD 信号增加。用荷包牡丹碱（一种 GABA(A)受体拮抗剂）处理可增加胃内输注 10%乙醇溶液后 BOLD 信号强度降低的区域的 BOLD 信号强度，但不会影响下丘脑的 BOLD 信号增加。用 SCH39166（一种 D1 样受体拮抗剂）处理可消除下丘脑区域 BOLD 信号强度的增加，但不会影响胃内输注 10%乙醇后 BOLD 信号的减少。这些结果表明，IG 乙醇负荷会导致未接触乙醇的大鼠的边缘系统和皮层中的 GABA(A)受体介导的 BOLD 降低，以及下丘脑区域中的 D1 样受体介导的 BOLD 增加。
