5-HT(1B) receptor in the suprachiasmatic nucleus of the common marmoset (Callithrix jacchus).
Serotonin (5-HT) is involved in the fine adjustments at several brain centers including the core of the mammal circadian timing system (CTS) and the hypothalamic suprachiasmatic nucleus (SCN). The SCN receives massive serotonergic projections from the midbrain raphe nuclei, whose inputs are described in rats as ramifying at its ventral portion overlapping the retinohypothalamic and geniculohypothalamic fibers. In the SCN, the 5-HT actions are reported as being primarily mediated by the 5-HT1 type receptor with noted emphasis for 5-HT(1B) subtype, supposedly modulating the retinal input in a presynaptic way. In this study in a New World primate species, the common marmoset (Callithrix jacchus), we showed the 5-HT(1B) receptor distribution at the dorsal SCN concurrent with a distinctive location of 5-HT-immunoreactive fibers. This finding addresses to a new discussion on the regulation and synchronization of the circadian rhythms in recent primates.
Laboratory of Chronobiology, Biosciences Center, Federal University of Rio Grande do Norte, 59072-970 Natal, RN, Brazil. jefsc@uol.com.br
Jeferson S
JS
Cavalcante
André L B
AL
de Pontes
Rovena C G J
RC
Engelberth
Judney C
JC
Cavalcante
Expedito S
ES
Nascimento
Janaína S
JS
Borda
Luciana
L
Pinato
Miriam S M O
MS
Costa
Claudio A B
CA
de Toledo
D000818:Animals; D002144:Callithrix / Q000033:anatomy & histology; D002772:Cholera Toxin / Q000378:metabolism; D003952:Diagnostic Imaging; D008297:Male; D044302:Receptor, Serotonin, 5-HT1B / Q000378:metabolism*; D013493:Suprachiasmatic Nucleus / Q000378:metabolism*; D014795:Visual Pathways / Q000378:metabolism
D044302:Receptor, Serotonin, 5-HT1B; D002772:Cholera Toxin