hippocampal field CA4 field of hippocampus region IV of ammon's horn CA4 field EMAPA:32771 neuronames:181 region 4 of Ammon's horn FMA:75741 HBA:12895 The last of four regions in the cornu ammonis of the hippocampus and is also part of the hilus of the dentate gyrus. This area contains mostly mossy cells that receive inputs from the dentate gyrus and pyramidal cells in the CA3 region and also projects back to the dentate gyrus. MA:0000953 EFO:0002457 region IV of hippocampus proper CA4 field of cornu ammonis PBA:10074 DHBA:10300 Wikipedia:Region_IV_of_hippocampus_proper NCIT:C32249 CA4 UBERON:0003884 hippocampus CA4 CA4 field of Ammon's horn