The distribution of specific binding of the 5-HT3 receptor ligand [3H]GR65630 in rat brain using quantitative autoradiography.
We have examined the distribution of specific binding of the 5-HT3 receptor ligand [3H]GR65630 to rat brain using quantitative autoradiography. Brain tissue was frozen and thin sections (20 microns) cut. Slide-mounted tissue sections were incubated with [3H]GR65630 (0.2 nM) in the presence or absence of metoclopramide (30 microM, to define non-specific binding). After drying, sections were apposed to photographic film for 3 months. Films were quantified for radioactivity using image analysis. The highest level of specific binding was found in the area postrema (34.0 fmol/mg tissue). Specific binding was high in intermediate layers of the cortex, particularly the entorhinal, temporal and pyriform cortex (5.2-7.0 fmol/mg tissue). Amongst sub-cortical areas, binding was evident in the olfactory lobes, olfactory tubercle, hippocampus and basolateral amygdala (1.3-3.3 fmol/mg tissue). Specific binding was below measurable levels in other sub-cortical areas.
Kilpatrick
G J
GJ
Department of Neuropharmacology, Glaxo Group Research Ltd., Ware, U.K.
Jones
B J
BJ
Tyers
M B
MB
D000818:Animals; D001345:Autoradiography; D001921:Brain / Q000378:metabolism*; D007093:Imidazoles / Q000378:metabolism*; D007211:Indoles / Q000378:metabolism*; D008297:Male; D008787:Metoclopramide / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011985:Receptors, Serotonin / Q000187:drug effects / Q000378:metabolism*; D014316:Tritium
D007093:Imidazoles; D007211:Indoles; D011985:Receptors, Serotonin; D014316:Tritium; C059068:GR 65630; D008787:Metoclopramide