Banca de DEFESA: SEBASTIAO PACHECO DUQUE NETO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : SEBASTIAO PACHECO DUQUE NETO
DATA : 21/02/2019
HORA: 14:00
LOCAL: Sala Darwin
TÍTULO:

Neuroanatomical Study of the Subparaventricular Zone (SPVZ) of the Marmoset (Callithrix jacchus): Cytoarchitecture, Neurochemical, and Retinal Projections Considerations, as well as its relationship with the Extended Circadian Rhythm System

PALAVRAS-CHAVES:

Circadian timing system; Subparaventricular zone; Retinohypothalamic tract; Citoarhitecture; Callithrix jacchus.

PÁGINAS: 129
GRANDE ÁREA: Ciências Humanas
ÁREA: Psicologia
RESUMO:

The circadian timing system (CTS) is composed of a set of neural structures responsible for the generation and modulation of the circadian rhythms. The suprachiasmatic nucleus (SCN) of the hypothalamus is the structure that generates the circadian rhythmicity, synchronizer with the 24h environmental light cycle. The SCN generates the expression of circadian rhythms in several diencephalic, telencephalic, and forebrain neural structures. Recently, has been proposed the concept of "extended circadian rhythm system", considering that there are almost 100 neural structures that could compose this system. Of the several regions involved in this context, the Subparaventricular Zone (SPVZ), the densest projects of the SCN, has been highlighted, although not yet studied, especially in primate species such as the Callithrix jacchus (marmoset). The objective of our study is to characterize its cytoarchitecture and neurochemical composition, and to map afferents from the retina in the SPVZ of the marmosets. We were able to identify the SPVZ cytoarchitecture in this species through the Nissl method and immunoreactivity for specific neuronal nuclear protein (NeuN), and glial fibrillary acidic protein (GFAP). We have identified the SPVZ located between the dorsal and caudal portions of the SCN, from its central level and retrochiasmatic region, and ventral portions of the hypothalamic paraventricular nucleus (PVN), distributing lateral to the third ventricle, occupying periventricular portions. The neurochemical content of calcium-binding proteins demonstrates a more pronounced presence of immunoreactive neurons for calbindin (CB) when compared to the few immunoreactive neurons for calretinin (CR) and non-marking for parvalbumin (PV). The CB immunoreactive neurons present a dorsolateral route, as well as the ventromedial, ventrolateral, and perisuprachiasmatic ventrolateral regions of SPVZ. It was also possible to observe in the ventromedial portion of SPVZ immunoreactive neural fibers to the neuropeptide Y (NPY), the enzyme decarboxylase of glutamic acid (GAD), and substance P (SP), whereas in the ventral and retrochiasmatic portions we observed immunoreactive 5-HT neuropil. The glutamate receptor subunit 1 (GluR1) is strongly present in the dorsal SPVZ. We also observed a bilateral distribution of axonal terminals of the immunoreactive retinohypothalamic tract (RHT) to the b subunit of the cholera toxin (CTb), which demonstrates retinal projection to the ventral and perisuprachiasmatic ventrolateral region, keeping topographic relationship with immunoreactive neurons for CB in this region. Although we did not perform functional experiments, the clear presence of CB in the marmoset SPVZ, and relationship with the SCN and PVN, together with the data available in the literature, places the marmoset SPVZ as an important region of the extended circadian rhythm system.

MEMBROS DA BANCA:
Interno - 4363493 - EXPEDITO SILVA DO NASCIMENTO JUNIOR
Presidente - 2351800 - JEFERSON DE SOUZA CAVALCANTE
Externo à Instituição - JOSÉ RODOLFO LOPES DE PAIVA CAVALCANTI - UERN
Externa à Instituição - MARIANA FERREIRA PEREIRA DE ARAUJO - IINN
Interna - 2140860 - ROVENA CLARA GALVAO JANUARIO ENGELBERTH