Objective To explore the temporal and spatial distribution of CCAAT/enhancer-binding protein homologous protein (CHOP) and calnexin (CNX) in the dentate gyrus of mesial temporal lobe epilepsy (mTLE) mouse model. Methods We used kainic acid (KA) to induce acute phase (12 h and 24 h) mTLE mouse models and performed Western blotting and immunofluorescence to detect the different expressions and distribution pattern of CHOP and CNX in CA3 of the hippocampus. Results Compared with the controls,the expressions of CHOP(F=1.136,P=0.4069) and CNX (F=2.378,P=0.2087) did not increase in CA3 of hippocampus 12 h following KA injection in the acute phase of mTLE mouse models,whereas the expressions in CA1 and CA3 of hippocampus 24 h after injection were significantly higher (F=8.510,P=0.0362;F=6.968,P=0.0497,respectively). As shown by immunofluorescence analysis,CHOP was expressed mainly in CA3 of hippocampus 12 h after KA injection,and increased in CA1 and CA3 24 h after KA administration. Compared with the controls,the expressions of CHOP(F=24.480,P=0.0057) and CNX (F=7.149,P=0.0478) were significantly higher 24 h after KA injection.Conclusions The expression of CHOP increases along with the progression of seizures,indicating the increased level of endoplasmic reticulum stress. An increasing number of CNX,which serves as molecular chaperone,may be needed to facilitate the unfolded protein to complete the folding process.