Banca de QUALIFICAÇÃO: MILENA SOARES LUSTOSA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : MILENA SOARES LUSTOSA
DATE: 29/07/2026
TIME: 09:00
LOCAL: On-line (Google meet)
TITLE:
Neurochemical Characterization of the Mesencephalic Dopaminergic Nuclei in Chicken Embryos (Gallus gallus domesticus)

KEY WORDS:
Mesencephalon. Chicken embryo. Dopamine. Neuroanatomy. Immunohistochemistry.

PAGES: 37
BIG AREA: Ciências Biológicas
AREA: Morfologia
SUMMARY:
Dopamine (DA) is one of the major monoaminergic neurotransmitters of the central
nervous system (CNS) and plays a fundamental role in the regulation of motor, cognitive, emotional,
and neuroendocrine functions. During embryonic development, the dopaminergic system (DS) is
involved in neuronal proliferation, differentiation, migration, and the establishment of neuronal
connections, being essential for the proper organization of neural circuits. In chicken embryos
(Gallus gallus domesticus) (CE), this system exhibits a high degree of evolutionary conservation
compared with mammals, making this model widely used in neurodevelopmental studies. In this
context, the present study aimed to morphologically characterize the mesencephalic dopaminergic
nuclei (DN) in CE by identifying their neuroanatomical organization and describing the morphology
of tyrosine hydroxylase (TH)-immunoreactive cells. For this purpose, embryos at 20 days of
development were incubated under controlled temperature and humidity conditions. Following
euthanasia, transcardial perfusion, and brain removal, the specimens were post-fixed,
cryoprotected, sectioned using a cryostat, and processed for Nissl staining and TH
immunohistochemistry. Analyses were performed using bright-field microscopy, with the stereotaxic
atlas of the chick brain serving as the anatomical reference for delineating the nuclei. The
combination of TH immunoreactivity and Nissl staining enable the establishment of anatomical
boundaries and the characterization of the cytoarchitecture of the mesencephalic dopaminergic
nuclei. TH-immunoreactive neurons were identified in the ventral tegmental area (VTA), substantia
nigra (SN), and retrorubral field (RRF), predominantly located within the dorsal mesencephalon.
Along the rostrocaudal axis, the VTA was the first nucleus to be identified, followed by the SN and
subsequently the RRF. The principal anatomical landmarks for their identification were the
narrowing of the third ventricle rostrally and the caudal termination of the fourth ventricle. Neurons
within the VTA and SN exhibited a predominantly rounded morphology and a diffuse distribution
pattern, whereas neurons in the RRF displayed a more compact organization, giving the nucleus a
lentiform appearance. These findings expand the current knowledge of the neuroanatomical
organization and cytoarchitecture of the mesencephalic dopaminergic nuclei in CE, providing a
morphological basis for comparative studies on the development of the dopaminergic system in
vertebrates and for future investigations into neurodevelopmental alterations.

COMMITTEE MEMBERS:
Externo à Instituição - ANDRÉ DE SÁ BRAGA OLIVEIRA - UFPB
Presidente - 4363493 - EXPEDITO SILVA DO NASCIMENTO JUNIOR
Externo à Instituição - FRANCISCO GILBERTO OLIVEIRA - URCA
Notícia cadastrada em: 17/07/2026 07:45
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