Cocaine seeking and self-administration responses in rats after operant and Pavlovian training contingencies

• Grant number: 16/22210-5
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: February 28, 2017
• End date: February 27, 2018
• Field of knowledge: Biological Sciences - Pharmacology - Neuropsychopharmacology
• Principal Investigator: Miriam Garcia Mijares
• Grantee: William Eduardo Patarroyo Serna
• Supervisor: Emilio Ambrosio Flores
• Host Institution: Instituto de Psicologia (IP). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: Universidad Nacional de Educación a Distancia (UNED), Spain
• Associated to the scholarship: 14/25020-7 - Self-administration and passive administration of morphine in rats: behavioral and genetic differences, BP.DR

Abstract

Studies reporting that repeated drug self-administration produces behavioral and physiological changes different from those produced by repeated passive administration of the same drug have been very important to understand mechanisms underlying drug abuse. This project main objective is to compare cocaine seeking and cocaine self-administration behaviors induced by a drug-related stimulus after an operant administration contingency and a Pavlovian administration contingency, as also compare the expression of DFosB, D1 and D2 dopaminergic receptors and NMDA glutamatergic receptors after those learning contingencies. To do so it will be used a yoked administration model in rats. Subjects will be distributed in three groups: cocaine contingent (CCoc), yoked cocaine (YCoc) and yoked saline (YSal). CCoc subjects will be trained on a discrimination task while the other groups receive passive administrations on Pavlovian training. Responding (nose poke) in the presence of S+ (sound stimuli) will have as consequence an infusion and S+ presentation. S- will be presented simultaneously for all groups. Then subjects will be no longer yoked and will be trained in a two-response chain task, seeking and self-administrating cocaine using two retractile bars. After achieving infusion stability, subjects will be exposed to transfers test. S+ and S- will be presented in trials and both bars will be presented. Responses will be registered and compared between groups.Subjects will be processed for DFosB gene expression immunohistochemistry and autoradiography for D1 and D2 dopaminergic receptors and NMDA glutamatergic receptors in selected brain regions and after different experimental phases will be quantified and compared between groups.