passages.id: split_1_test_1639_passage
passages.type: progene_text
passages.text: We found that 1) hypoxia induced apoptosis in the hippocampus and basal forebrain ; 2 ) the NF-kappa B dimers c-Rel / p50 and p50 / p50 bound to the bcl-x promoter NF-kappa B sequence ( CS4 ) in the hippocampus , but only p50 / p50 bound to the CS4 sequence in the basal forebrain and hypoxia - induced differential binding patterns of c-Rel / p50 and p50 / p50 correlated with the bcl-x expression pattern in the hippocampus ; 3) the hypoxia - induced patterns of binding of c-Rel / p50 to the bcl - x promoter CS4 sequence were different from those to the IgG-kappa B enhancer sequence , whereas those of p50 / p50 were similar to both sequences ; 4 ) nuclear protein levels of c-Rel , but not p50 , correlated with the c-Rel / p50 DNA binding patterns to the bcl - x CS4 site ; and 5 ) there were differential responses to hypoxia among the different NF-kappa B protein subunits .