Prairie vole breeder pairs form monogamous pair bonds, which are maintained through the expression of selective aggression toward novel conspecifics. Here, we utilize behavioral and anatomical techniques to extend the current understanding of neural mechanisms that mediate pair bond maintenance. For both sexes, we show that pair bonding up-regulates mRNA expression for genes encoding D1-like dopamine (DA) receptors and dynorphin as well as enhances stimulated DA release within the nucleus accumbens (NAc). We next show that D1-like receptor regulation of selective aggression is mediated through downstream activation of kappa-opioid receptors (KORs) and that activation of these receptors mediates social avoidance. Finally, we also identified sex-specific alterations in KOR binding density within the NAc shell of paired males and demonstrate that this alteration contributes to the neuroprotective effect of pair bonding against drug reward. Together, these findings suggest motivational and valence processing systems interact to mediate the maintenance of social bonds.DOI: http://dx.doi.org/10.7554/eLife.15325.001

Cues (conditioned stimuli; CSs) associated with rewards can come to motivate behavior, but there is considerable individual variation in their ability to do so. For example, a lever-CS that predicts food reward becomes attractive, wanted, and elicits reward-seeking behavior to a greater extent in some rats (“sign-trackers”; STs), than others (“goal-trackers”; GTs). Variation in dopamine (DA) neurotransmission in the nucleus accumbens (NAc) core is thought to contribute to such individual variation. Given that the DA transporter (DAT) exerts powerful regulation over DA signaling, we characterized the expression and function of the DAT in the accumbens of STs and GTs. STs showed greater DAT surface expression in ventral striatal synaptosomes than GTs, and ex vivo fast-scan cyclic voltammetry recordings of electrically-evoked DA release confirmed enhanced DAT function in STs, as indicated by faster DA uptake, specifically in the NAc core. Consistent with this, systemic amphetamine (AMPH) produced greater inhibition of DA uptake in STs than in GTs. Furthermore, injection of AMPH directly into the NAc core enhanced lever-directed approach in STs, presumably by amplifying the incentive value of the CS, but had no effect on goal tracking behavior. On the other hand, there were no differences between STs and GTs in electrically-evoked DA release in slices, or in total ventral striatal DA content. We conclude that greater DAT surface expression may facilitate the attribution of incentive salience to discrete reward cues. Investigating this variability in animal sub-populations may help explain why some people abuse drugs, while others do not.

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is a ground breaking collection of film footage, videographies of the top BPP leaders and video oral histories of the members of the News Reel who worked to publicize and support the work of the Black Panther Party, movement organizations and individuals in general. This collection of four DVDs is unsurpassed in its breadth and knowledge of those most closely associated with the inner workings, growth, development, and decline of the BPP. It is a welcome addition to the rapidly growing research on civil rights and black power now being conducted by scholars throughout the US and around the globe. Roz Payne's thoroughly researched and well-edited video collection is one that will be indispensable to those seeking to understand the phenomenon J. Edgar Hoover chose to dub the "greatest threat to the internal security of the United States." Included in this collection are well-known short documentary films like Off the Pig!, May Day and Repression. These short films, often less than twenty minutes in length, cover the early history of Black Panther Party and the major events that brought it headlines in the late sixties and early seventies. One sees footage where an imprisoned Huey Newton speaks candidly about why there was a need for the BPP. Viewers witness party co-founder Bobby Seale read Executive Mandate number one on the steps of the Sacramento Capital where he called for blacks nationwide to take note of the "racist California legislature" that was preparing to pass a law to "disarm" blacks and take away their second amendment rights to bear arms. This spectacle swelled the group's numbers from thirty to nearly 4,000 in a few months time. Minister of Information and infamous author Eldridge Cleaver chimes in with a few choice four-letter words and explains why it is important to blacks and their white, brown, red, and yellow allies to make the police feel the same fear that blacks had grown to know over the centuries. While all of this is classic footage that makes for excellent teaching tools, the newsreel team made it clear that their task was not only to document and preserve the history of this radical organization but also to use their films to educate "the people" and to recruit new members into party. In other words, they were scholar activists long before the term became popular in the late twentieth century. Newsreel's role in the life of the BPP is the part of the collection that makes it so unique. The stories that the newsreel film team and the lawyers who fought for and supported the party through uncounted legal battles tell are at the same time heartbreaking and courageous. The members of the newsreel family from New York to California lay bare their hearts in an attempt to tell their individual stories of how they came to know, love, work with, and finally to leave the BPP and carry on with the rest of their lives. Movement lawyers follow suit with stories of intrigue, betrayal, innovative and new defenses, and plain old good luck.