Banca de DEFESA: RAONI DA CONCEIÇÃO DOS SANTOS

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : RAONI DA CONCEIÇÃO DOS SANTOS
DATA : 15/02/2019
HORA: 09:00
LOCAL: Departamento de Ciências Fisiológicas
TÍTULO:

THE INFLUENCE OF GHRELIN ON BEHAVIOR AND THE ACTIVITY OF PARAVENTRICULAR HYPOTHALAMIC NUCLEUS AND BASOLATERAL AMYGDALA NEURONS.

PALAVRAS-CHAVES:

Key words: ghrelin, food intake control, anxiety-like behavior, basolateral amygdala, paraventricular hypothamalic nucleus

PÁGINAS: 70
GRANDE ÁREA: Ciências Biológicas
ÁREA: Fisiologia
SUBÁREA: Fisiologia de Órgãos e Sistemas
ESPECIALIDADE: Fisiologia Endócrina
RESUMO:

Dos-Santos, Raoni da Conceição.THE INFLUENCE OF GHRELIN ON BEHAVIOR AND THE ACTIVITY OF PARAVENTRICULAR HYPOTHALAMIC NUCLEUS AND BASOLATERAL AMYGDALA NEURONS. 2018.70pThesis (Doctorate in Physiological Sciences). Institute of Biological and Health Sciences, Department of Physiological Sciences, Federal Rural University of Rio de Janeiro, Seropédica, Rj, 2019.

Ghrelin is an orexigenic hormone produced by the stomach. Additional to its effects on food intake, ghrelin also affects a series of physiological variables, such as the neuroendocrine control, autonomic and cardiovascular function, the response to stress, and anxiety-like and depression-like behaviors. The paraventricular hypothalamic nucleus (PVN) and the basolateral amygdala (BLA) are brain nuclei involved in the integration of several of ghrelin’s effects. To elucidate the effects of ghrelin on the activity of PVN neurons we used extracellular and intracellular electrophysiological recordings in ex vivo brain slices and observed that ghrelin may increase or decrease the spike frequency of PVN neurons; however, the excitatory effects are direct while the inhibitory effects are indirect. We also observed that ghrelin affects the majority of neurons in this nucleus, whether they are pre-autonomic, neuroendocrine parvocellular or neuroendocrine magnocellular; and that the most TRH, CRH and OT PVN neurons are hyperpolarized in response to ghrelin. Similarly, we performed intracelular recordings in BLA neurons and showed that ghrelin increases or decreases the membrane potential in neurons in this nucleus. Next, we analyzed the behavioral alterations caused by food deprivation, a physiological stimulus that increases plasma ghrelin, and the exogenous administration of ghrelin on anxiety-like behaviors and exploratory activity. In these experiments we showed that food deprivation decreases anxiety-like behavior in the elevated plus maze and does not change exploratory activity on the open field and modified open field. However, ghrelin did not affect anxiety-like behavior in the elevated plus maze. Taken together the results described in this thesis showed that ghrelin affects brain nuclei involved in the control of several physiological functions, thus providing a neurobiological substrate for ghrelin’s effects for some functions of this hormone. However, we did not observe behavioral alterations caused by ghrelin, which suggests that future studies are necessary to elucidate the participation of ghrelin on the behavioral responses that mediate the response to situations of caloric deficits, such as food deprivation.

MEMBROS DA BANCA:
Presidente - 387295 - LUIS CARLOS REIS
Interno - 3000663 - DAVID DO CARMO MALVAR
Interno - 386960 - WELLINGTON DA SILVA CORTES
Externo à Instituição - ISIS HARA TREVENZOLI - UFRJ
Externo à Instituição - DANILO LUSTRINO BORGES - UFS