Shieh Kun-Ruey, Yang Shu-Chuan
Department of Physiology, Tzu Chi University, Hualien, Taiwan.
Holistic Education Center, Tzu Chi University of Science and Technology, Hualien, Taiwan.
Chin J Physiol. 2020 Jan-Feb;63(1):27-34. doi: 10.4103/CJP.CJP_47_19.
Three-quarters of the lands in Taiwan are over 1000 m above sea level. Formosan wood mice (Apodemus semotus), also called Taiwanese field mice, are largely found at altitudes of 1400 ~ 3700 m and are the dominant rodents in these areas. Notably, Formosan wood mice show high levels of exploratory behaviors, not only in the wild but also in laboratory situations. Therefore, in this study, we examined the behavioral responses and central dopaminergic activities of male C57BL/6J mice and Formosan wood mice in the open field test. Dopamine and its major metabolite 3,4-dihydroxyphenylacetic acid were used as indices of dopaminergic activities. Formosan wood mice showed higher levels of exploration and locomotor activity than C57BL/6J mice in the open field test. Higher central dopaminergic activities in the nucleus accumbens, striatum, and medial prefrontal cortex were found in Formosan wood mice than in C57BL/6J mice in the open field test. Higher levels of locomotion and central dopaminergic activities in Formosan wood mice were consistent after two exposures to the open field test; however, dramatic decreases in levels of locomotion and central dopaminergic activities in C57BL/6J mice were found after two exposures to the open field test. The present study found that Formosan wood mice exhibited higher levels of locomotor activity and exploration and central dopaminergic activities than C57BL/6J mice after one or two exposures to the open field test.
台湾四分之三的土地海拔超过1000米。高山白腹鼠，也被称为台湾田鼠，主要分布在海拔1400至3700米的地区，是这些地区的优势啮齿动物。值得注意的是，高山白腹鼠不仅在野外，而且在实验室环境中都表现出高水平的探索行为。因此，在本研究中，我们在旷场试验中检测了雄性C57BL/6J小鼠和高山白腹鼠的行为反应和中枢多巴胺能活性。多巴胺及其主要代谢产物3,4-二羟基苯乙酸被用作多巴胺能活性的指标。在旷场试验中，高山白腹鼠比C57BL/6J小鼠表现出更高水平的探索和运动活动。在旷场试验中，发现高山白腹鼠伏隔核、纹状体和内侧前额叶皮质的中枢多巴胺能活性高于C57BL/6J小鼠。高山白腹鼠在两次暴露于旷场试验后，运动和中枢多巴胺能活性水平保持一致；然而，C57BL/6J小鼠在两次暴露于旷场试验后，运动和中枢多巴胺能活性水平显著下降。本研究发现，在一次或两次暴露于旷场试验后，高山白腹鼠比C57BL/6J小鼠表现出更高水平的运动活动、探索和中枢多巴胺能活性。
