title: Magnetic material in the human hippocampus.
abstract: Magnetic analyses of hippocampal material from deceased normal and epileptic subjects, and from the surgically removed epileptogenic zone of a living patient have been carried out. All had magnetic characteristics similar to those reported for other parts of the brain [6]. These characteristics along with low temperature analysis indicate that the magnetic material is present in a wide range of grain sizes. The low temperature analysis also revealed the presence of magnetite through manifestation of its low temperature transition. The wide range of grain sizes is similar to magnetite produced extracellularly by the GS-15 strain of bacteria and unlike that found in magnetotactic bacteria MV-1, which has a restricted grain size range. Optical microscopy of slices revealed rare 5-10 micron clusters of finer opaque particles, which were demonstrated with Magnetic Force Microscopy to be magnetic. One of these was shown with EDAX to contain AI, Ca, Fe, and K, with approximate weight percentages of 55, 19, 19, and 5, respectively.
authors.affiliation: Department of Geological Sciences, University of California at Santa Barbara 93106.
authors.forename: J R
authors.initials: JR
authors.lastname: Dunn
authors.forename: M
authors.initials: M
authors.lastname: Fuller
authors.forename: J
authors.initials: J
authors.lastname: Zoeger
authors.forename: J
authors.initials: J
authors.lastname: Dobson
authors.forename: F
authors.initials: F
authors.lastname: Heller
authors.forename: J
authors.initials: J
authors.lastname: Hammann
authors.forename: E
authors.initials: E
authors.lastname: Caine
authors.forename: B M
authors.initials: BM
authors.lastname: Moskowitz
mesh_terms: D004827:Epilepsy / Q000378:metabolism* / Q000503:physiopathology; D052203:Ferrosoferric Oxide; D006624:Hippocampus / Q000737:chemistry* / Q000502:physiology / Q000503:physiopathology; D006801:Humans; D007501:Iron; D008280:Magnetics; D010087:Oxides; D012016:Reference Values; D013696:Temperature
chemical_list: D010087:Oxides; D007501:Iron; D052203:Ferrosoferric Oxide