Effect of the selective lesion of serotoninergic neurons on the regional distribution of 5-HT1A receptor mRNA in the rat brain.
The effects of the selective lesion of serotoninergic neurons by an intra-raphe administration of 5,7-dihydroxytryptamine on the 5-HT1A receptor protein and the 5-HT1A receptor mRNA were examined in various regions of the rat brain using specific antibodies and an antisense riboprobe, respectively. Twenty one days after the treatment, the 5-HT1A receptor protein was no longer detected within the dorsal raphe nucleus but was still present in the hippocampus and entorhinal cortex. Quantitative in situ hybridization showed an 85% decrease in the levels of 5-HT1A receptor mRNA within the dorsal raphe nucleus, but no significant change in the hippocampus, interpeduncular nucleus and entorhinal cortex of 5,7-dihydroxytryptamine-treated rats. These data demonstrate that 5-HT1A receptors are synthesized by serotoninergic neurons in the dorsal raphe nucleus, and by neurons located postsynaptically with regard to serotoninergic projections in other areas. The unchanged levels of 5-HT1A receptor mRNA in the hippocampus, interpeduncular nucleus and entorhinal cortex three weeks after the extensive lesion of serotoninergic neurons are consistent with the absence of 5-HT1A receptor up regulation already reported under this condition.
Miquel
M C
MC
INSERM U288, Faculté de Médecine Pitié-Salpêtrière, France.
Doucet
E
E
Riad
M
M
Adrien
J
J
Vergé
D
D
Hamon
M
M
D015116:5,7-Dihydroxytryptamine; D000818:Animals; D015306:Biogenic Monoamines / Q000032:analysis; D001923:Brain Chemistry / Q000502:physiology*; D008297:Male; D009474:Neurons / Q000502:physiology*; D012333:RNA, Messenger / Q000032:analysis*; D051381:Rats; D011919:Rats, Inbred Strains; D011985:Receptors, Serotonin / Q000235:genetics*; D012701:Serotonin / Q000502:physiology*
D015306:Biogenic Monoamines; D012333:RNA, Messenger; D011985:Receptors, Serotonin; D015116:5,7-Dihydroxytryptamine; D012701:Serotonin