Hemicholinium-3 binding sites in rat brain: a quantitative autoradiographic study.
Quantitative in vitro autoradiography was used to study the distribution of [3H]hemicholinium-3 ([3H]HC-3) binding sites in the rat brain. Regional concentrations of HC-3 binding sites were corrected for regional tissue quenching of tritium in a number of brain structures. Specific binding of 10 nM [3H]HC-3 was highest in the interpeduncular nucleus, followed by the caudate-putamen, olfactory tubercle, amygdala, and the medial and lateral habenulae. There was a high positive correlation between regional HC-3 binding and choline acetyltransferase activity in rat brain; however, a novel pattern of the distribution of cholinergic terminals in the subnuclei of the interpeduncular nucleus was discovered. The apparent Kd in the 1-5 nM range and the pharmacological specificity of the HC-3 binding site agreed with data for choline uptake and for the HC-3 binding site as determined in membrane preparations. HC-3 autoradiography appears to be a useful anatomical marker for cholinergic terminals.
Bekenstein
J W
JW
Department of Neurology, University of Virginia School of Medicine, Charlottesville 22908.
Wooten
G F
GF
D000818:Animals; D001285:Atropine / Q000378:metabolism; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism*; D002794:Choline / Q000378:metabolism; D006426:Hemicholinium 3 / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012601:Scopolamine / Q000378:metabolism
D006426:Hemicholinium 3; D001285:Atropine; D012601:Scopolamine; D002794:Choline