Study of the behavior of two distinct strains of Rattus norvegicus, selected with a greater or lesser tendency to exhibit sociable behaviors

• Grant number: 20/04376-9
• Support type: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): October 01, 2020
• Effective date (End): September 30, 2022
• Field of knowledge: Humanities - Psychology - Physiological Psychology
• Principal researcher: Christie Ramos Andrade Leite Panissi
• Grantee: Rafael Carvalho Bonuti
• Home Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

The rat is a social animal and lives in well-defined colonies composed of males and females. Aiming to study social behavior, Bonuti and Morato (2018) proposed a sociability test by decreasing the interference that one animal has over the other during the experimental sessions, and Bonuti (2018) used it to selectively breed rats that showed greater (SOC +) and less (SOC-) tendency to sociability and produced two distinct strains of animals. SOC- rats exhibiting less motivation to interact than SPC+ rats. Also, they exhibited behaviors that can be interpreted as anxiety in various tested apparatus, raising the question that, when selectively breed animals with a greater or lesser degree of motivation to interact, may have occurred a selection of more sociable animals on the one hand and more anxious/fearful animals on the other. In addition, the analysis of mRNA expression of melatonin receptors in SOC + animals showed differences in several brain areas (hypothalamus, hippocampus, cerebellum and prefrontal cortex). Taken together, these data revealed the need for psychopharmacological, neurophysiological or biochemical studies that can better explore the emotional components selected over the generations, especially investigating brain areas related to both social behavior and anxiety/fear as well as possible relationships between them. Possible access routes for the study of the probable neuroanatomical and biochemical differences between these two strains would be structures related to sociability (olfactory system) and empathy (anterior cingulate cortex, insula), as well as structures related to anxiety/fear (System of Behavioral Inhibition, Aversive Cerebral System). Thus, the objective of this study will be to investigate behaviors related to anxiety and sociability in two strains of animals (SOC + and SOC-) in the structures mentioned above using the techniques that investigate genes of immediate expression (c-Fos and BNDF). As a result, less sociable rats (SOC-) are expected to exhibit more prominent anxiety-related behaviors, with a consequent increase in the detection of Fos protein and BNDF in structures related to anxiety/fear, while more sociable rats (SOC +) on the other. On the other hand, they will present more prominent behaviors related to sociability and empathy, with a consequent increase in the detection of Fos and BNDF protein in structures related to sociability and empathy than less sociable rats. With the realization of this study we will be able to advance in the understanding of the neural circuits recruited in individuals with different social behaviors. In addition, this proposal aims to characterize an experimental model for the study of social behavior disorders, which can be decisive for future studies aimed at the development of new therapeutic approaches. (AU)