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.

GluR2/3 label expression of the AMPA-type glutamate receptor in the hippocampal formation of the homing pigeon stabilizes just after birth.

The compositions of the glutamate AMPA-type receptors influence the neural response and the subunits GluR2/3 has been referred to as essential for receptor trafficking and synapse consolidation. We investigate the GluR2/3 occurrence and expression in the hippocampal formation of newly born homing pigeons by a semi-quantitative approach, the Western-blotting technique and by immunohistochemistry. Immunoreactivity for GluR2/3 occurs before hatching has been evident in neuropil that was fully dispersed over the hippocampus proper (HP) and the area parahippocampalis (APH).

Discrete retinal input to the parabrachial complex of a new-world primate, the common marmoset (Callithrix jacchus).

Traditional retinal projections target three functionally complementary systems in the brain of mammals: the primary visual system, the visuomotor integration systems and the circadian timing system. In recent years, studies in several animals have been conducted to investigate the retinal projections to these three systems, despite some evidence of additional targets. The aim of this study was to disclose a previously unknown connection between the retina and the parabrachial complex of the common marmoset, by means of the intraocular injection of cholera toxin subunit b.

Disruption of maternal behaviour by acute conspecific interaction induces selective activation of the lateral periaqueductal grey.

Maternal behaviour is sensitive to stress and opioidergic activation. The periaqueductal grey (PAG) is involved in coping strategies to stress, whereas morphine inhibition of maternal behaviour depends on the activation of the PAG. The aim of this study was to investigate whether the PAG is activated by disrupting maternal behaviour.