The abnormal distribution of mossy fiber bundles and morphological abnormalities in hippocampal formation of dreher(J) (dr(J)/dr(J))mouse.
The organization of pyramidal cells and mossy fibers in the hippocampal formation of homozygous dreher(J) mutant mice was investigated using Timm's and Golgi methods. Five clear abnormalities were found: (1) some pyramidal cells were located below the infrapyramidal mossy fiber layer, (2) mossy fibers emerged in diffuse fashion from between the suprapyramidal and infrapyramidal mossy fiber layers, and their fibers invaded within the pyramidal cell layer, where they traveled as 3-6 small, usually quite short, bundles, (3) some normally situated pyramidal cells had unusual contacts with mossy fibers at two or three places on their apical and/or basal dendrites, (4) some normally situated pyramidal cells had abnormal dendritic trees typified by the occurrence of fine-caliber dendritic branches extending out of the apical dendrite or the apical portion of the soma, and (5) a few Timm positive fibers extending from the dentate hilus to the dentate molecular layer in both dreher(J) and control mice were observed. These abnormalities indicate that in the hippocampal formation a variety of cell populations and neuronal circuits can be indirectly modified by the dreher mutation.
Sekiguchi
M
M
Department of Morphology, Tokai University School of Medicine, Kanagawa, Japan.
Abe
H
H
Nagato
Y
Y
Tanaka
O
O
Guo
H
H
Nowakowski
R S
RS
D000818:Animals; D005260:Female; D006056:Golgi Apparatus / Q000648:ultrastructure; D006624:Hippocampus / Q000473:pathology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008818:Mice, Neurologic Mutants / Q000033:anatomy & histology*; D009412:Nerve Fibers / Q000473:pathology*; D012016:Reference Values