Bozarth, M.A. (1983). Opiate reward mechanisms mapped by intracranial self-administration. In J.E. Smith and J.D. Lane (eds.), Neurobiology of Opiate Reward Processes (pp. 331-339). Amsterdam: Elsevier/North Holland Biomedical Press. [This is an example of an article published in a book.]
This book chapter reviews data suggesting that the ventral tegmental area is critically involved in opiate reward. In addition it presents the first of several theoretical reviews by the author suggesting that opiate and psychomotor stimulant reinforcement involves activation of the same dopaminergic substrate. (By the mid-1980s the notion that different addictive drugs might share a common reward substrate would become paradigmatic for the study of drug reinforcement and addiction.) Control procedures and other methodological issues for conducting intracranial self-administration studies are also discussed.
Bozarth, M.A. (1987). (ed.) Methods of Assessing the Reinforcing Properties of Abused Drugs. New York: Springer-Verlag. [This is an example of a book citation.]
This book provides the definitive compendium of the experimental methods used to study drug reinforcement. Thirty chapters written by leading experts in each technique provide synopses of the experimental procedures. Both preclinical and clinical methods are presented, grouped by general approach (e.g., preclinical reinforcement studies, preclinical conditioning methods, clinical subjective-effects measures, clinical self-administration procedures). Most chapters present an overview and review of an experimental method, while some chapters provide original experimental data illustrating specific applications of a technique.
Interestingly, none of the researchers presented physical dependence tests as a method of assessing potential drug reinforcement; this is probably because of the editor’s assertion that physical dependence is not a primary motivation for drug-taking behavior and because of the obvious consensus shared by his contributing authors. The book sold-out shortly after its publication and has not been reprinted. It is, however, available in its entirety on the Internet at www.AddictionScience.net and can be downloaded chapter-by-chapter without charge.
Bozarth, M.A. (1987). Conditioned place preference: A parametric analysis using systemic heroin injections. In M.A. Bozarth (Ed.), Methods of assessing the reinforcing properties of abused drugs (pp. 241-273). New York: Springer-Verlag. [This is an example of an article published in a book.]
This chapter provides both a brief review and original data from the author’s extensive work using this experimental method. Although conditioned place preference appears to be a reliable and valid measure of potential drug reward, several experimental manipulations that usually have strong effects on conditioned responses had only modest effects on conditioned place preference. The author’s conclusion is that the experimental method is not well understood and he cautions against the ‘reckless’ use of this technique by experimenters unaware of it’s potential problems. Specific recommendations include the necessity of always testing a concurrent control group, including a positive control when a drug effect is not obtained. The author emphasizes the importance of replication and of independent corroboration using other experimental methods. Although he may appear somewhat skeptical of the method, he does assert that it has special applications where it is invaluable and has published other studies using this technique (e.g., Bozarth, 1987; Bozarth, 1990; Bozarth & Wise, 1981).
Bozarth, M.A., & Wise, R.A. (1981). Intracranial self-administration of morphine into the ventral tegmental area. Life Sciences28: 551-555. [This is an example of an article published in a scientific journal.]
This is the first study showing that morphine produces a reinforcing effect when microinjected directly into the ventral tegmental area (origin of the mesolimbic dopamine pathway). Other investigators have since replicated and extended this finding. (This paper is highly cited, with over 450 citations since its publication in 1981.)
Bozarth, M.A., & Wise, R.A. (1981). Heroin reward is dependent on a dopaminergic substrate. Life Sciences29: 1881-1886. [This is an example of an article published in a scientific journal.]
This study suggests that heroin reward involves activation of a dopaminergic reward substrate. The findings was challenged by several other research groups, but other investigators have since replicated this important finding. There remains some debate even today regarding the exact role of dopamine in opiate reward processes, but there is good agreement that dopamine is involved and most investigators concur with the original assertion of the authors. Interestingly, Bozarth seems somewhat skeptical of the conditioned place preference method used in this study, although this appears to represent one of the technique’s important applications that other experimental methods cannot adequately address. (This paper is highly cited, with over 350 citations since its publication in 1981).
Bozarth, M.A., Murray, A., & Wise, R.A. (1989). Influence of housing conditions on the acquisition of intravenous heroin and cocaine self-administration in rats. Pharmacology Biochemistry & Behavior33: 903-907. [This is an example of an article published in a scientific journal.]
This study reports that both socially isolated and group-housed rats learned to intravenously self-administer cocaine and heroin. Housing conditions had only a small effect on the acquisition of intravenous heroin self-administration and no effect on learning to self-administer cocaine. This might appear to conflict with some later studies reporting that housing conditions can influence learning intravenous drug self-administration, but it is probably in general agreement with those studies. Bozarth et al. used ‘satiating’ doses of both cocaine and heroin, while author’s reporting larger differences from housing conditions use low, marginally reinforcing drug doses. The effect of housing conditions appears minimal except when animals are tested with very low drug doses. This may be important for humans beginning their experimentation with illicit drugs, but the Bozarth et al., study clearly shows that isolation-induced stress is not necessary for drugs to be reinforcing. (The was the primary objective of the study.)
Wise, R.A., & Bozarth, M.A. (1987). A Psychomotor stimulant theory of addiction. Psychological Review94: 469-492. [This is an example of an article published in a scientific journal.]
This theoretical review summarizes the authors’ arguments suggesting that a common neural substrate mediates the rewarding properties of various abused drugs. (It also provides a brief critique of positive and negative reinforcement models of drug addiction.) The mesolimbic dopamine system is postulated to underlie drug reward, electrical brain stimulation reward, and forward locomotion (e.g., exploratory behavior), and this relationship is suggested to be founded in evolutionary biology—reinforcing drugs and other incentive stimuli produce forward locomotion by activating the mesolimbic dopamine system and this motivated behavior contributes to species survival. Complications of discerning behavioral activation when opposing drug effects are produced are also discussed as illustrated by the neuroanatomical dissociation of opiate effects. (This article is one of the most highly cited papers in experimental psychology, receiving over 2,000 citations since its publication.)