New approach for the study of body temperature regulation using activity control of GABAergic neurons

下丘脑的GABA能神经元在体温调节中起着重要作用。在本研究中，我创造了新的转基因小鼠，在其中GABA能神经元表达光激活蛋白，如通道视紫红质2(ChR2)或卤视紫红质(HALO)来控制GABA能神经元的活动。四环素反式激活剂(TTA)被插入到GAD67基因等位基因GAD67-TTA小鼠中。这些小鼠与Teto ChR2小鼠杂交，产生双基因小鼠。在这些小鼠的大脑中，ChR2在GABA神经元中有表达。然而，ChR2的表达水平太低，不能控制GABA神经元的活动。这可能是由于GAD67-TTA小鼠TTA基因附近的新霉素抗性基因盒干扰了TTA的表达所致。为了去除Neo盒式磁带，这些小鼠与Cre小鼠杂交。然后，将这些小鼠与Teto ChR2小鼠再次杂交。而ChR2的表达水平未见增加。今后，我将尝试用病毒载体代替转基因方法将ChR2导入GABA能神经元。

GABAergic neurons in the hypothalamus play an important role in the regulation of body temperature. In the present research, I generated new transgenic mice in which GABAergic neurons express light activated proteins, such as channelrhodopsin2(ChR2) or Halorhodopsin(Halo) to control the activity of GABAergic neurons. Tetracycline transactivator(tTA) is inserted in the GAD67 gene allele, GAD67-tTA mice. These mice were crossed with TetO ChR2 mice to generate bi-genic mice. In these mice brain, ChR2 expression is observed in the GABA neurons. However, the expression level of ChR2 is too low to control the activity of GABA neurons. This might be caused by neomycin resistant gene cassette located near tTA gene in the GAD67-tTA mice interfered tTA expressin. To remove Neo cassette, these mice were crossed with Cre mice. Then, these mice were crossed with TetO ChR2 mice again. However, expression level of ChR2 was not increased. In future, I will try virus vector instead of transgenic method to introduce ChR2 in GABAergic neurons.