Quantitative determination of seven major absorbed volatile constituents in mice brain, liver and blood after intragastric administration of Asari Radix et Rhizoma suspension by headspace-solid phase microextraction-gas chromatography-mass spectrometry Pharmacokinetics of gastrodigenin in brain tissue of mice after intragastric administration of gastrodin Comparison of Metallothionein-3 Gene Expression Levels in Different Brain Parts of Tibetan-sheep Between Different Altitudes Areas Analysis of chemical constituents of Chuanxiong Rhizoma absorbed into rat brain tissues by UPLC-Q-TOF-MS Research on volatile components of Gualou Guizhi decoction and its components in rat brain by GC-MS