part of part of hippocampus stratum oriens CA1 stratum oriens UBERON:0014552 DMBA:16132 BAMS:so neuronames:2939 MBA:399 FMA:277856 Part of stratum oriens lying in area CA1, superficial to the alveus of CA1 and deep to the pyramidal cell layer of CA1. It is continuous with the stratum oriens of CA2 and bounded by the subiculum. oriens layer of CA1 field CA1 stratum oriens PBA:10059 BIRNLEX:4116 stratum oriens of the CA1 field layer of CA1 field