passages.id: split_6_test_1529_passage
passages.type: progene_text
passages.text: For example , in the hippocampus the phosphorylated type 1 inositol 1,4,5-trisphosphate receptor is restricted to CA1 , while the unphosphorylated receptor occurs ubiquitously in CA1-CA3 and dentate gyrus granule cells .