Amphetamine reward in the monogamous prairie vole

Abstract

Recent studies have shown that the neural regulation of pair bonding in the monogamous prairie vole (Microtus ochrogaster) is similar to that of drug seeking in more traditional laboratory rodents. Therefore, strong interactions between social behavior and drug reward can be expected. Here, we established the prairie vole as a model for drug studies by demonstrating robust amphetamineinduced conditioned place preferences in this species. For both males and females, the effects of amphetamine were dose-dependent, with females being more sensitive to drug treatment. This study represents the first evidence of drug reward in this species. Future studies will examine the effects of social behavior on drug reward and the underlying neurobiology of such interactions.Keywords drug abuse; addiction; conditioned place preference; attachment; social bonding; monogamy There are many factors that contribute to drug abuse. Included among these are genetic predisposition and drug availability, variables that have been well modeled with traditional laboratory rodents and that have been shown to greatly influence drug seeking behavior [1,18,22,59]. However, there are other complexities known to influence drug taking in humans, such as social environment [31]. This variable is more difficult to study in the laboratory because traditional rodent subjects do not exhibit social organization analogous to that shown by humans [4]. Studies in non-human primates demonstrate the importance of social hierarchy on drug taking [39]. However, primate experiments are not practical for most laboratories and therefore understanding the neurobiology of interactions between social behavior and drug abuse would be greatly facilitated if it were studied in rodent models. Here, we have taken an initial step toward this end by establishing a highly social rodent species, the monogamous prairie vole (Microtus ochrogaster), for drug studies.The prairie vole is a powerful model for studies of social attachment [13,23]. Males and females of this species show preferential mating with one partner [20], exhibit high levels of parental behavior [36][37][38]43], and form enduring pair bonds, which are maintained even if one member of the pair is lost [57]. Pair bond formation is routinely studied in the laboratory by using a partner preference test [60,61] and such studies have provided excellent insight into the neural regulation of pair bonding [62]. In particular, recent studies have shown that pair bond formation and maintenance critically depend on key components of brain reward circuitry, Correspondence to: Zuoxin Wang, Ph.D., Department of Psychology, Florida State University, Tallahassee, FL 32306-1270, Phone: 850-644-5057, Fax: 850-644-7739, E-mail: E-mail: zwang@psy.fsu.edu. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the res...

Nucleus accumbens dopamine mediates amphetamine-induced impairment of social bonding in a monogamous rodent species

“…In this study, we replicate our previous finding that AMPH exposure induces CPP in male prairie voles (22) and demonstrate that D1R activation in the NAcc is necessary for this behavior, a result consistent with studies in other rodent species (28). This finding, together with earlier studies, suggests that distinct DAergic mechanisms in the NAcc regulate AMPH-and partner-motivated behaviors: AMPH-motivated behavior (CPP) is mediated by D1R, whereas partner-motivated behavior (partner preferences) is facilitated by D2R activation and inhibited by D1R activation within the NAcc (13)(14)(15).…”

“…The neurobiology of such social attachment, specifically pair bonding between adults, has been extensively studied in the prairie vole (10)(11)(12), and recently, this species has been established as a viable model to examine the motivational value of AMPH (22). Moreover, both pair bond formation and AMPH reinforcement are mediated, at least in part, by DA transmission within the NAcc (14,15,23).…”

Anterior hypothalamic vasopressin regulates pair-bonding and drug-induced aggression in a monogamous rodent

“…The following behavioral patterns of the resident were subsequently quantified: the frequency of attacks, bites, chases, defensive/offensive upright postures, offensive sniffs, threats, and retaliatory attacks, and calculated as a composite score (aggression frequency) (26), as well as the duration of affiliative side-by-side physical contact (28). Procedures for stereotaxical cannulation, site-specificinfusions, and AMPH injections were described previously (25,51). Bilateral guide cannulae were stereotaxically implanted and aimed into the AH (coordinates from bregma: posterior 0.55 mm, lateral Ϯ 0.75 mm, ventral 5.9 mm).…”

Drinking alcohol has sex-dependent effects on pair bond formation in prairie voles

“…In both species, social reward and drug reward show striking parallels at the behavioral and neurobiological levels (5-9). Prairie voles are now being used to explore the interactions between social relationships and drug abuse (10)(11)(12)(13)(14)(15)(16)(17)(18)(19).We previously demonstrated that prairie voles voluntarily selfadminister substantial amounts of alcohol (ethanol) and can influence the drinking patterns of a social partner (16)(17)(18)(19), similar to social drinking in humans (20). Because alcohol is known to influence social bonds in humans (21-24), we asked here whether alcohol consumption can affect the formation of adult social attachments in prairie voles.…”

“…In both species, social reward and drug reward show striking parallels at the behavioral and neurobiological levels (5-9). Prairie voles are now being used to explore the interactions between social relationships and drug abuse (10)(11)(12)(13)(14)(15)(16)(17)(18)(19).…”