CHARACTERIZATION OF CIRCADIAN CLOCK PROTEINS Per1, Cry1, and MELATONIN RECEPTORS IN PRIMATE HIPPOCAMPUS Sapajus apella

• Grant number: 23/07124-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): February 01, 2024
• Effective date (End): January 31, 2025
• Field of knowledge: Biological Sciences - Physiology - General Physiology
• Principal Investigator: Leila Maria Guissoni Campos
• Grantee: Ana Letícia Carneiro de Camargo
• Host Institution: Universidade de Marília (UNIMAR). Marília , SP, Brazil

Abstract

The presence of phylogenetically preserved neural networks influenced by circadian oscillations in the brain represents an essential functional characteristic of mammals. The circadian information generated by the suprachiasmatic nucleus, through a feedback loop of expression of called clock genes, modulates rhythmic behaviors through local neural circuits and broad endogenous actions. Likewise, melatonin participates in the modulation of several physiological and behavioral phenomena necessary for the adaptation of individuals and species to cyclical environmental changes, such as the light- dark cycle. Circadian scale oscillatory phenomena have already been identified in several brain areas, such as spinal cord, cerebral cortex, hypothalamus, medial geniculate nucleus, basal ganglia, cerebellum and hippocampus with possible circadian influence on the functions of these areas. Hippocampal functions are related to interconnected processes such as learning and memory, spatial orientation, motivated and emotional behaviors, which can be sensitive to environmental changes. The light/dark cycle is the main synchronizing environmental variation for the endogenous biological rhythms of humans and other animals. The understanding of how these endogenous rhythms are generated and/or modulated in different brain areas represents one of the aspects of research in chronobiology, the science that studies biological rhythms. This work aims to investigate the day/night- time differences from the neurochemical expression pattern of the Per1, Cry, and MT1 and MT2 (melatonin receptors) in the different neuronal layers of the primate Sapajus apella hippocampus using the immunohistochemistry technique. Brain sections containing the hippocampus of 6 Sapajus apella monkeys will be used. Previous experiments will be carried out to test the effectiveness of the immunohistochemistry technique. The results may open perspectives for studies that explore the relationship between the structures of the circadian timing system in learning and memory.