Involvement of highly polysialylated neural cell adhesion molecule (PSA-NCAM)-positive granule cells in the amygdaloid-kindling-induced sprouting of a hippocampal mossy fiber trajectory.
The mossy fiber system in the hippocampus of amygdaloid-kindled rats was examined by using highly polysialylated neural cell adhesion molecule (PSA-NCAM) as a marker for immunohistochemical detection of immature dentate granule cells and mossy fibers in combination with bromodeoxyuridine (BrdU) labeling of newly generated granule cells. Statistically significant increases in BrdU-labeled cells and PSA-NCAM-positive cells occurred in the dentate gyrus following kindling. The increase in PSA-NCAM-immunoreactive neurites was confined to the entire stratum lucidum of CA3. Immunoelectron-microscopic examination also revealed that PSA-NCAM-positive immature synaptic terminals of the sprouting mossy fibers increased in the stratum lucidum of CA3 in the kindled rats. The increase in the numbers of PSA-NCAM-positive granule cells correlated well with the increase in the immunopositive neurites and synaptic terminals on the mossy fiber trajectory. The increase in these PSA-NCAM-immunopositive structures is thought to reflect the enhancement of sprouting and synaptogenesis of mossy fibers by a subset of granule cells newly generated during amygdaloid-kindling and suggests that the reorganization of the mossy fiber system on the normal trajectory at least in part contributes to the acquisition and maintenance of an epileptogenic state.
Saegusa
Takashi
T
Department of Neurological Surgery, Graduate School of Medicine, Chiba University, Inohana 1-8-1, Chuo-ku, Chiba 260-8670, Japan. saegusa-nsu@umin.ac.jp
Mine
Seiichiro
S
Iwasa
Hiroto
H
Murai
Hisayuki
H
Seki
Tatsunori
T
Yamaura
Akira
A
Yuasa
Shigeki
S
D000679:Amygdala / Q000737:chemistry* / Q000378:metabolism; D000818:Animals; D006624:Hippocampus / Q000737:chemistry / Q000378:metabolism / Q000502:physiology; D007696:Kindling, Neurologic / Q000378:metabolism*; D008297:Male; D019599:Mossy Fibers, Hippocampal / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology*; D039842:Neural Cell Adhesion Molecule L1 / Q000032:analysis / Q000096:biosynthesis / Q000502:physiology*; D009434:Neural Pathways / Q000737:chemistry / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012794:Sialic Acids / Q000032:analysis / Q000096:biosynthesis / Q000502:physiology*
D039842:Neural Cell Adhesion Molecule L1; D012794:Sialic Acids; C103469:polysialyl neural cell adhesion molecule