Localization of [125I]omega-conotoxin GVIA binding in human hippocampus and cerebellum.
The peptide toxin omega-conotoxin GVIA (omega-CgTx) has been shown to be a high affinity ligand for N-type calcium channels in the brain. We have employed [125I]omega-CgTx to localize N-type channels in human hippocampus and cerebellum using autoradiography. Ten micron thick slide-mounted tissue sections of human cerebellum and hippocampus were labeled with [125I]omega-CgTx under various conditions. Specific binding to human cerebellum was virtually irreversible and saturable. It was displaceable by the N-channel antagonist, omega-conotoxin MVIIA, but not by L- or P-channel ligands. Binding sites were heterogeneously distributed with denser binding in the molecular layer than the granule cell layer of cerebellum and with specific laminar patterns evident in the hippocampus. [125I]omega-CgTx should be a useful tool for the study of N-type calcium channels in human brain tissue.
Albensi
B C
BC
Neuroscience Program, University of Utah, Salt Lake City 84132.
Ryujin
K T
KT
McIntosh
J M
JM
Naisbitt
S R
SR
Olivera
B M
BM
Fillous
F
F
D001345:Autoradiography; D001667:Binding, Competitive / Q000187:drug effects; D001923:Brain Chemistry / Q000502:physiology; D015220:Calcium Channels / Q000378:metabolism; D002531:Cerebellum / Q000033:anatomy & histology / Q000378:metabolism*; D006624:Hippocampus / Q000033:anatomy & histology / Q000378:metabolism*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007457:Iodine Radioisotopes; D007700:Kinetics; D010455:Peptides / Q000378:metabolism*; D020866:omega-Conotoxin GVIA
D015220:Calcium Channels; D007457:Iodine Radioisotopes; D010455:Peptides; D020866:omega-Conotoxin GVIA