Self-administration and passive administration of morphine in rats: behavioral and genetic differences

• Grant number: 14/25020-7
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: September 01, 2015
• End date: March 31, 2019
• Field of knowledge: Humanities - Psychology - Experimental Psychology
• Principal Investigator: Miriam Garcia Mijares
• Grantee: William Eduardo Patarroyo Serna
• Host Institution: Instituto de Psicologia (IP). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated scholarship(s): 16/22210-5 - Cocaine seeking and self-administration responses in rats after operant and Pavlovian training contingencies, BE.EP.DR

Abstract

Studies reporting that repeated drug self-administration produces behavioral and genetic changes different from those produced by repeated passive administration of the same drug have been very important to understand mechanisms underlying drug abuse. Research in the area have focused on changes produced by drugs such as cocaine and amphetamine, not existing publications reporting behavioral or genetic differences between passive administration and self-administration of morphine, a drug with a high dependence potential and action mechanism different from stimulants. This project proposes two experiments to evaluate behavioral and genetic differences produced between morphine self-administration under operant contingency and morphine passive administration under Pavlovian contingency, using a yoked administration model in rats. Rats will be distributed in three groups: morphine contingent (MC), morphine yoked (MY) and saline yoke (SY). In Experiment 1, MC subjects will be exposed to intravenous morphine self-administration sessions (operant contingency). MC will receive a morphine infusion whenever it press a bar; simultaneously, yoked MY and SY will receive a passive infusion of morphine or vehicle. After establishing self-administration, ””FosB gene expression in different parts of the brain (immunohistochemistry) will be quantified and compared between groups. Experiment 2 will have three phases. It will be used the same procedure as in Experiment 1 for Phase 1, but each infusion will be accompanied by a light stimulus (S1). In Phase 2, groups will be trained to emit a response chain (search - morphine self-administration), being no longer yoked. In Phase 3, S1 discrete trials will be presented in extinction. Morphine seeking and self-administration responses will be recorded and compared between groups.

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

SERNA, William Eduardo Patarroyo. Morphine and Cocaine Administration Under Operant and Pavlovian Trainings: Genetic and Behavioral Differences in Rats. 2019. Doctoral Thesis - Universidade de São Paulo (USP). Instituto de Psicologia (IP/SBD) São Paulo.