50 research outputs found
Heroin versus cocaine: opposite choice as a function of context but not of drug history in the rat
Rationale
Previous studies have shown that rats trained to self-administer heroin and cocaine exhibit opposite preferences, as a function of setting, when tested in a choice paradigm. Rats tested at home prefer heroin to cocaine whereas rats tested outside the home prefer cocaine to heroin. Here we investigated whether drug history would influence subsequent drug preference in distinct settings. Based on a theoretical model of drug-setting interaction, we predicted that regardless of drug history rats would prefer heroin at home and cocaine outside the home.
Methods
Rats with double-lumen catheters were first trained to self-administer either heroin (25 μg/kg) or cocaine (400 μg/kg) for 12 consecutive sessions. Twenty-six rats were housed in the self-administration chambers (thus, they were tested at home) whereas 30 rats lived in distinct home cages and were transferred to self-administration chambers only for the self-administration session (thus, they were tested outside the home). The rats were then allowed to choose repeatedly between heroin and cocaine within the same session for 7 sessions.
Results
Regardless of the training drug, the rats tested outside the home preferred cocaine to heroin whereas the rats tested at home preferred heroin to cocaine. There was no correlation between drug preference and drug intake during the training phase.
Conclusion
Drug preferences were powerfully influenced by the setting but, quite surprisingly, not by drug history. This suggests that, under certain conditions, associative learning processes and drug-induced neuroplastic adaptations play a minor role in shaping individual preferences for one drug or the other
Estimativa de pessoas com diagnóstico de câncer no Brasil: dados da Pesquisa Nacional de Saúde, 2013
High prevalence and clustering of modifiable CVD risk factors among rural adolescents in southwest Nigeria: implication for grass root prevention
Recent remobilisation of shallow-level material on Montserrat revealed by hydrogen isotope composition of amphiboles
Degassing at the Soufrière Hills volcano, Montserrat recorded in matrix glass compositions
The volcanic evolution of Montserrat using <sup>40</sup>Ar/<sup>39</sup>Ar geochronology
Experimental constraints on andesite petrogenesis at Soufrière Hills volcano, Montserrat
Eyewitness accounts of the 25 June 1997 pyroclastic flows at Soufrière Hills Volcano, Montserrat, and implications for disaster mitigation
Isolation of a Specialized, Antigen-Loaded Early Endosomal Subpopulation by Flow Cytometry
Geomorphological evolution of Montserrat (West Indies): Importance of flank collapse and erosional processes
Analysis of topography and new swath bathymetry as well as geophysical data provides information about aerial and submarine morphological features and mass transfer processes on Montserrat. The island has a characteristic shallow