Liu Wen, Thielen Richard J, Rodd Zachary A, McBride William J
Institute of Psychiatric Research, Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
Alcohol. 2006 Nov;40(3):167-76. doi: 10.1016/j.alcohol.2007.01.001. Epub 2007 Mar 7.
The objectives of the present study were to (a) examine the effects of activating serotonin-3 (5-HT3) receptors on dopamine (DA) release in the anterior and posterior ventral tegmental area (VTA) of Wistar rats and (b) determine if there are differences in 5-HT3--stimulated DA release in the VTA between alcohol-preferring (P) and Wistar rats. Local perfusion with the 5-HT3 agonist 1-(m-chlorophenyl)-biguanide (CPBG) in the anterior and posterior VTA stimulated DA release in both the regions. The CPBG-stimulated increase in extracellular DA levels was significantly higher in the posterior than anterior VTA of Wistar rats. The basal extracellular DA levels were not significantly different between the anterior and posterior VTA of Wistar rats. However, the basal extracellular DA levels were significantly higher in the posterior VTA of Wistar rats than P rats. Local perfusion of CPBG into the posterior VTA stimulated somatodendritic DA release significantly more in the P than Wistar rat. Overall, the results indicate that there may be a heterogeneous distribution of functional 5-HT3 receptors within the VTA, with higher numbers in the posterior than anterior VTA, and that, compared to 5-HT3 receptors in Wistar rats, 5-HT3 receptors in the posterior VTA of P rats may be more responsive to stimulation.
(a) 研究激活血清素-3（5-HT3）受体对Wistar大鼠腹侧被盖区（VTA）前后部多巴胺（DA）释放的影响；(b) 确定在酒精偏好（P）大鼠和Wistar大鼠的VTA中，5-HT3刺激的DA释放是否存在差异。在前VTA和后VTA局部灌注5-HT3激动剂1-（间氯苯基）-双胍（CPBG），均可刺激这两个区域的DA释放。在Wistar大鼠中，CPBG刺激引起的细胞外DA水平升高在后VTA显著高于前VTA。Wistar大鼠前VTA和后VTA的基础细胞外DA水平无显著差异。然而，Wistar大鼠后VTA的基础细胞外DA水平显著高于P大鼠。将CPBG局部灌注到后VTA中，对P大鼠树突-胞体DA释放的刺激作用显著大于Wistar大鼠。总体而言，结果表明VTA内功能性5-HT3受体可能存在异质性分布，后VTA中的数量高于前VTA，并且与Wistar大鼠的5-HT3受体相比，P大鼠后VTA中的5-HT3受体可能对刺激更敏感。
