Visualization of calcium channels involved in transmitter release from neuronal growth cones.
Immunocytological localization of omega-agatoxin IVA (omega-aga IVA)-sensitive Ca2+ channels involved in glutamate release from growth cones of cultured rat dorsal root ganglion (DRG) neurons was studied with field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The omega-aga IVA-sensitive Ca2+ channels were visualized by labeling with immuno-gold particles (30 nm). FE-SEM and TEM images showed that immuno-gold particles were present in the area of growth cones as well as somata, and generally absent on neurite stem and fibroblasts. TEM images of vertical ultra-thin sections showed that the immuno-gold particles were present on the surface of the plasma membrane. Since the gold particles indicate the immunological presence of omega-aga IVA-sensitive Ca2+ channels, the Ca2+ channels involved in transmitter release are present on growth cones before making synapse formation.
Department of Anatomy, Nihon University School of Dentistry at Matsudo, Chiba, Japan.
H
H
Soeda
H
H
Tatsumi
Y
Y
Kozawa
H
H
Mishima
Y
Y
Katayama
D000818:Animals; D015220:Calcium Channels / Q000502:physiology*; D002478:Cells, Cultured; D005727:Ganglia, Spinal / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D017348:Microscopy, Electron, Scanning Transmission; D009474:Neurons / Q000378:metabolism* / Q000502:physiology* / Q000648:ultrastructure; D018377:Neurotransmitter Agents / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
D015220:Calcium Channels; D018377:Neurotransmitter Agents