Characterization and validation of the social version of the place preference conditioning paradigm in Wistar rats

• Grant number: 23/02497-1
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: August 01, 2023
• End date: February 28, 2027
• Field of knowledge: Biological Sciences - Pharmacology - Neuropsychopharmacology
• Principal Investigator: Carlos Eduardo Neves Girardi
• Grantee: Marina de Oliveira Rodrigues Barbosa
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil

Abstract

Social behavior encompasses the actions of an individual towards another of the same species and occurs throughout an individual's life. Social play is quite predominant in the behavioral repertoire of adolescent rats and involves motivational, hedonic and cognitive processes, possibly mediated by neuromodulators, including opioids and endocannabinoids. One way to assess the motivational, hedonic and cognitive aspects of social interactions is the conditioned place preference (CPP) paradigm, widely used for other reinforcing stimuli, such as drugs of abuse and natural rewards. Although it is recognized that social play is a reinforcing stimulus capable of eliciting this type of conditioning, there is no consensus in the literature regarding its use in the social version, as well as little is known about the action of endocannabinoids in the hedonic and cognitive processes involved in the Social CPP. Our aim is to characterize and validate the social version of the place preference conditioning paradigm (sCPP), in addition to evaluating the effect of anandamide on the processes of acquisition and expression of place preference conditioning associated with social interactions, evidencing the mediation of this process via signaling by type 1 cannabinoid receptors (CB1). In the first step, we will evaluate the potential of our CPP apparatus to promote discriminatory perception through its characteristics of its environmental cues, using it with classically reinforcing and effective stimuli in CPP, such as cocaine and palatable and high-calorie food (chocolate). In the second stage, male and female Wistar rats will be tested in the sCPP to verify the best response in relation to the duration and number of pairing sessions, prior isolation or not, use of a familiar partner or not. Finally, the third step consists of the pharmacological approach. A dose-response curve will be made to evaluate the effectiveness of an anandamide degradation inhibitor (URB597) and a CB1 receptor antagonist (rimonabant) in promoting changes in social play. Later, we will verify the effect of the administration (i.p.) of these drugs (alone or combined) in the acquisition and expression phases of the sCPP. With this, we hope to characterize a replicable model that allows discoveries about the reinforcing character of social interactions and elucidate the role of endocannabinoids, and if there is involvement of CB1 signaling, in this type of associative learning. (AU)