Synthetic cathinones, otherwise known as “bath salts”, have gained significant attention in the last few years as a result of increased use and abuse. One such compound, 3,4-methylenedioxypyrovalerone (MDPV), is pharmacologically and behaviorally similar to cocaine and has been shown to possess both aversive and rewarding effects. For a host of other drugs, each of these effects (and their relative balance) can be influenced by a variety of factors, including sex, which in turn impacts drug taking behavior. In this context, the present assessment sought to determine whether males and females differed in MDPV-induced CTA and CPP. Both male and female Sprague-Dawley rats underwent a combined CTA/CPP procedure, in which an injection of one of three doses of MDPV (1.0, 1.8 or 3.2 mg/kg) was paired with both a novel saccharin solution and a novel environment and changes in preferences for these stimuli were examined. Taste avoidance was evident in both sexes, although this avoidance was weaker in females compared to males. MDPV also produced place preferences in all drug-treated animals, but these preferences did not vary as a function of sex. The fact that females showed a weaker avoidance response compared to males (despite comparable preferences) suggests that females may have a heightened susceptibility to use and abuse of MDPV, paralleling results seen with cocaine and other stimulants. The present findings extend the behavioral characterization of MDPV and the factors that may alter its aversive and rewarding effects.

OBJECTIVE Most drugs of abuse have both aversive and rewarding effects, and the use and abuse potential of such drugs is thought to be a function of a balance of these affective properties. Characterizing these effects and their relative balance may provide insight into abuse vulnerability. One drug that has received recent attention is methylenedioxyparavalerone (MDPV), a monoamine transport inhibitor similar to, but significantly more potent than, cocaine. MDPV is self-administered and has been shown to produce aversive and rewarding effects in adult rats. The present study extended this characterization of the affective properties of MDPV by examining its ability to support place conditioning at a range of doses known to produce taste avoidance. METHODS Male Sprague-Dawley rats were injected with MDPV (1, 1.8 or 3.2 mg/kg) or saline and placed on the non-preferred side of a place conditioning apparatus for 30 min. On the next day, they were given an injection of saline and placed on the preferred side. This was repeated three times for a total of four conditioning cycles, and side preference was assessed on a final test. RESULTS All doses of MDPV produced significant increases in time spent in the drug-paired chamber, an effect not seen in vehicle-treated animals. CONCLUSIONS That the same doses of MDPV induced both taste avoidance and place preference allows assessments of how other factors might impact these effects and how they may, in turn, contribute to its abuse liability.

The inbred Fischer (F344) and Lewis (LEW) rats, while originally developed as animal models for cancer and tissue transplantation research, have since been used to study genetic differences in a variety of physiological and behavioral endpoints. In this context, LEW rats show greater sensitivity to the aversive effects of cocaine as compared to F344 rats in a conditioned taste avoidance procedure. Like cocaine, 3,4-methylenedioxypyrovalerone (MDPV; “Bath Salts”) acts as a dopamine transport blocker and possesses aversive properties, making it a good candidate for assessing whether the aforementioned strain differences with cocaine would generalize to drugs with similar biochemical action. Accordingly, male F344 and LEW rats were exposed to a novel saccharin solution followed by injections of one of four doses of MDPV in a taste avoidance procedure. Over the four saccharin/MDPV pairings during conditioning, core body temperatures were also assessed. Similar to previous research, MDPV induced robust dose-dependent taste avoidance, although no effect of strain was observed. MDPV also produced hyperthermia that was independent of strain and unrelated to the conditioned taste avoidance. These findings argue for a complex influence of multiple (and likely interacting) monoaminergic systems mediating MDPV-induced taste avoidance in the two strains and suggest different mechanisms of avoidance learning for cocaine and MDPV.

Necrotizing fasciitis is an orthopedic emergency. The ability to quickly and accurately diagnose this rapidly spreading disease can save a patient's life and limb. However, the diagnosis is complex because necrotizing fasciitis usually manifests as a less severe cellulitis or abscess while the majority of the damages rage beneath the surface of the skin. Although the diagnosis is not new, the potential causes and vectors continually change. This article reports a new source of necrotizing fasciitis in an intramuscular injection of "bath salts," a rapidly emerging street drug that is legal in some states and evades authorities with its innocuous name. The patient presented 2 days after injection of bath salts with extensive cellulitis extending to the mid portion of her upper arm. The cellulitis initially responded to broad-spectrum intravenous antibiotics, but rapidly deteriorated 48 hours later, leading to a forequarter amputation with radical mastectomy and chest wall debridement to obtain healthy tissue margins and control the disease. The patient made a full recovery after further minor debridements, negative pressure dressings, directed antibiotic therapy, and skin grafting. The recent emerging popularity of this highly obtainable, injectable substance may lead to an increase in cases of necrotizing fasciitis. Orthopedic surgeons should be vigilant in diagnosing this process early and should perform an extensive debridement.

Drugs of abuse have both rewarding and aversive effects, as indexed by the fact that they support place preferences and taste aversions, respectively. In the present study, we explored whether having a history with the aversive effects of morphine (via taste aversion conditioning) impacted the subsequent rewarding effects of morphine, as measured in the place preference design. In Experiment 1, rats were exposed to a taste aversion procedure in which saccharin was followed by morphine. Place preference conditioning was then initiated in which animals were injected with morphine and placed on one side of a two-chambered apparatus. Animals with a taste aversion history acquired place preferences to the same degree as controls without such a history, suggesting that morphine's affective properties condition multiple effects, dependent on the specific stimuli present during conditioning. To determine whether these results were a reflection of processes operating in traditional associative conditioning, in a modified blocking procedure, place preference conditioning was attempted in the presence of a taste previously associated with morphine (Exp. 2). Under these conditions, animals still acquired morphine-induced place preferences comparable to those of animals without a morphine or conditioning history. These results are consistent with the position that drugs of abuse have multiple stimulus effects (positive and negative) that are differentially associated with specific stimuli (environmental and taste) that drive different behavioral responses (approach and avoidance).