Quantitative autoradiography of 5-HT1E binding sites in rodent brains: effect of lesion of serotonergic neurones.
Binding sites corresponding to 5-HT1E receptors were labelled in mouse, rat, and guinea-pig brains by using [3H]5-hydroxytryptamine ([3H]5-HT) in the presence of 5-carboxamidotryptamine (5-CT) (0.1 microM), and their distribution within the brain was studied by quantitative autoradiography. The results obtained with mouse brain show that 5-HT1E binding sites are particularly present in the cortex, caudate-putamen and claustrum, where they showed the highest density. Lower densities were measured in other regions. Saturation experiments showed that the affinity of [3H]5-HT for 5-HT1E binding sites (nanomolar range) was very similar in the different structures. The distribution of 5-HT1E binding sites was similar in rat and guinea-pig brains. In rat brain, selective lesioning of serotonergic fibres by intracerebroventricular injection of 5,7-dihydroxytryptamine (5,7-DHT), a specific 5-HT neurotoxin, did not affect the density of 5-HT1E binding, indicating that these receptors are mainly localized on non-serotonergic neurones.
Barone
P
P
Laboratoire de Pharmacologie N.I.E., Institut Pasteur, Paris, France.
Millet
S
S
Moret
C
C
Prudhomme
N
N
Fillion
G
G
D015116:5,7-Dihydroxytryptamine / Q000494:pharmacology; D000818:Animals; D001345:Autoradiography; D001667:Binding, Competitive / Q000187:drug effects; D001921:Brain / Q000033:anatomy & histology; D001923:Brain Chemistry / Q000502:physiology*; D004873:Ergolines / Q000494:pharmacology; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D008566:Membranes / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D011869:Radioligand Assay; D051381:Rats; D017208:Rats, Wistar; D011985:Receptors, Serotonin / Q000378:metabolism*; D012701:Serotonin / Q000031:analogs & derivatives / Q000494:pharmacology / Q000502:physiology*; D017366:Serotonin Receptor Agonists / Q000494:pharmacology
D004873:Ergolines; D011985:Receptors, Serotonin; D017366:Serotonin Receptor Agonists; D015116:5,7-Dihydroxytryptamine; D012701:Serotonin; C047087:5-carboxamidotryptamine; C031649:mesulergine