Wistar　rats　were　exposed　to　a　916　MHz,　10　W/m(2)　mobile　phone　electromagnetic　field　for　6　hours　a　day,　5　days　a　week.　Average　completion　times　in　an　eight-arm　radial　maze　were　longer　in　the　exposed　rats　than　control　rats　after　4-5　weeks　of　exposure.　Error　rates　in　the　exposed　rats　were　greater　than　the　control　rats　at　6　weeks.　Hippocampal　neurons　from　the　exposed　rats　showed　irregular　firing　patterns　during　the　experiment,　and　they　exhibited　decreased　spiking　activity　6-9　weeks　compared　with　that　after　2-5　weeks　of　exposure.　These　results　indicate　that　916　MHz　electromagnetic　fields　influence　learning　and　memory　in　rats　during　exposure,　but　long-term　effects　are　not　obvious.