Banca de QUALIFICAÇÃO: NELYANE NAYARA MARTINS DE SANTANA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : NELYANE NAYARA MARTINS DE SANTANA
DATE: 28/01/2021
TIME: 14:00
LOCAL: Videoconferência
TITLE:

Morfo-quantitative and neurochemical analysis of subcortical visual system in aged marmoset (Callithrix jacchus)

KEY WORDS:

Aging; Dorsal Lateral Geniculate nucleus; Superior Colliculus; Stereology; optical density

PAGES: 103
BIG AREA: Ciências Humanas
AREA: Psicologia
SUMMARY:

The Dorsal Lateral Geniculate Nucleus (DLG) and the Superior Colliculus (SC) are structures that comprise the subcortical visual system. Functionally, DLG is considered a first-order thalamic nucleus in the processing of visual information, with relay properties and modulating the retinal inputs to the visual cortex. The CS participates in transferring incoming retinal inputs to other subcortical visual structures and sensorimotor transformations to drive movements of orientation and attention of the eyes and head. These two subcortical nuclei constitute the two main visual pathways in mammals, contributing to the interpretation and subsequent formulation of adequate visual responses by the visual cortex. However, this visual processing is altered by aging, leading progressive functional deficits. Despite these, few studies discuss possible morphological and neuropeptidergic changes that may be directly related to the decline in visual function during aging. In this context, the present study aims to describe quantitatively morphological and neurochemical parameters in the DLG and CS in response to the aging process. Female and male marmosets (Callitrix jaccus) were divided into two age groups: adults (~36 months old) and aged (~119-140 months old) and perfused with formalin (10%). Then, the brains were sectioned (30µm) and submitted to Nissl method and immunohistochemistry for glial fibrillary acidic protein (GFAP), serotonin (5-HT) and subunit B of cholera toxin (CTb), the latter is a neural tracer used to reveal and characterize the patterning of retinal innervation. Through the optical density (OD) and design-based stereological techniques, such as Cavalieri estimator, the immunoexpression of GFAP, 5-HT, the CTb-IR retinal pattern, as well as the total and DLG layers volume were analyzed, respectively. Preliminarily, our results evidence a decrease in GFAP immunoexpression, as well as an increase in the total volume and DLG magnocellular, parvocellular and koniocellular layers in aged animals. Qualitatively, we observed a decrease in the number of CTb-IR terminal buttons in aged animals, in addition to small varicosities when compared to adult animals. No significant difference was found in 5-HT neurochemical stain.

BANKING MEMBERS:
Externo ao Programa - 1076490 - FERNANDO VAGNER LOBO LADD
Interno - 2351800 - JEFERSON DE SOUZA CAVALCANTE
Presidente - 2140860 - ROVENA CLARA GALVAO JANUARIO ENGELBERTH