The lipid-sensitive mechano-gated TREK-1 has been shown to be predominantly expressed in the CNS.However, its regional and cellular expression under ischemic conditions remains to be determined.In this study, we examined the expression of TREK-1 in the rat central nervous system using an immunohistoehemical approach under physiological and focal ischemia conditions.The results show that TREK-1 was broadly expressed in the cortex, CA1 and DG region of hippocampus and subventricular zone.Moreover, TREK-1 was preferentiallyexpressed on astrocytes.After focal ischemia, the TREK-1 expression was obviously increased at days 3, 7 and 30 following reperfusion compared with control, which correlated with activation and proliferation of astrocytes.Since TREK-1 mediated K+ conductance establishes a low resting membrane potential for the optimal operation of astrocyte brain homeostatic functions, these data provides important insights into the astrocytic TREK-1 involvement in ischemia pathology.