Expedito Silva do Nascimento

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The mediodorsal thalamic nucleus is a prominent nucleus in the thalamus, positioned lateral to the midline nuclei and medial to the intralaminar thalamic complex in the dorsal thalamus. Several studies identify the mediodorsal thalamic nucleus as a key structure in learning and memory, as well as in emotional mechanisms and alertness due to reciprocal(More)
The thalamic paraventricular nucleus (PVT) receives afferents from numerous brain areas, including the hypothalamic suprachiasmatic nucleus (SCN), considered to be the major circadian pacemaker. The PVT also sends projections to the SCN, limbic system centers and some nuclei involved in the control of the Sleep-Wake cycle. In this study, we report the(More)
In this study, two circadian related centers, the suprachiasmatic nucleus (SCN) and the intergeniculate leaflet (IGL) were evaluated in respect to their cytoarchitecture, retinal afferents and chemical content of major cells and axon terminals in the rock cavy (Kerodon rupestris), a Brazilian rodent species. The rock cavy SCN is innervated in its ventral(More)
Serotonin, or 5-hydroxytryptamine (5-HT), is a substance found in many tissues of the body, including as a neurotransmitter in the nervous system, where it can exert different post-synaptic actions. Inside the neuro-axis, 5-HT neurons are almost entirely restricted to the raphe nuclei of the brainstem. As such, 5-HT-immunoreactivity has been considered a(More)
The 3-hydroxytyramine/dopamine is a monoamine of the catecholamine group and it is a precursor of the noradrenaline and adrenaline synthesis, in which the enzyme tyrosine hydroxylase acts as a rate-limiting enzyme. The dopaminergic nuclei retrorubral field (A8 group), substantia nigra pars compacta (A9 group) and ventral tegmental area (A10 group) are(More)
Animals have neural structures that allow them to anticipate environmental changes and then regulate physiological and behavioral functions in response to these alterations. The suprachiasmatic nucleus of the hypothalamus (SCN) is the main circadian pacemaker in many mammalian species. This structure synchronizes the biological rhythm based on photic(More)
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(More)
The circadian timing system (CTS) anticipates optimal physiological patterns in response to environmental fluctuations, such as light-dark cycle. Since age-related disruption of circadian synchronization is linked to several pathological conditions, we characterized alterations of neurochemical constituents and retinal projections to the major pacemaker of(More)
The thalamic midline/intralaminar complex is part of the higher-order thalamus, which receives little sensory input, and instead forms extensive cortico-thalamo-cortical pathways. The midline thalamic nuclei connect with the medial prefrontal cortex and the medial temporal lobe. On the other hand, the intralaminar nuclei connect with the fronto-parietal(More)
The dopamine (DA) neurons of the retrorubral field (RRF - A8), the substantia nigra (SN - A9), and the ventral tegmental area (VTA - A10) have been implicated in motor regulation, reward, aversion, cognition, and several neuropsychiatric disorders. A series of studies have identified subdivisions of these cell groups in rodents, but these cell groups have(More)
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