U.S. immigrants have faced a changing landscape with regard to immigration enforcement over the last two decades. Following the passage of the Illegal Immigration Reform and Immigrant Responsibility Act of 1996, and the creation of the Immigration and Customs Enforcement (ICE) agency after the attacks of September 11, 2001, detention and deportation activity increased substantially. As a result, immigrants today are experiencing heightened fear of profiling and deportation. Little research exists on how these activities affect the health and well-being of U.S. immigrant communities. This study sought to address this gap by using community-based participatory research to investigate the impact of enhanced immigration enforcement on immigrant health in Everett, Massachusetts, USA, a city with a large and diverse immigrant population. Community partners and researchers conducted 6 focus groups with 52 immigrant participants (documented and undocumented) in five languages in May 2009. The major themes across the groups included: 1) Fear of deportation, 2) Fear of collaboration between local law enforcement and ICE and perception of arbitrariness on the part of the former and 3) Concerns about not being able to furnish documentation required to apply for insurance and for health care. Documented and undocumented immigrants reported high levels of stress due to deportation fear, which affected their emotional well-being and their access to health services. Recommendations from the focus groups included improving relationships between immigrants and local police, educating immigrants on their rights and responsibilities as residents, and holding sessions to improve civic engagement. Immigration enforcement activities and the resulting deportation fear are contextual factors that undermine trust in community institutions and social capital, with implications for health and effective integration processes. These factors should be considered by any community seeking to improve the integration process.

It has been suggested that incentive salience plays a major role in drug abuse and the development of addiction. Additionally, novelty seeking has been identified as a significant risk factor for drug abuse. However, how differences in the readiness to attribute incentive salience relate to novelty seeking and drug abuse vulnerability has not been explored. The present experiments examined how individual differences in incentive salience attribution relate to novelty seeking and acquisition of cocaine self-administration in a preclinical model. Rats were first assessed in an inescapable novelty task and a novelty place preference task (measures of novelty seeking), followed by a Pavlovian conditioned approach task for food (a measure of incentive salience attribution). Rats then were trained to self-administer cocaine (0.3 or 1.0 mg/kg/infusion) using an autoshaping procedure. The results demonstrate that animals that attributed incentive salience to a food-associated cue were higher novelty seekers and acquired cocaine self-administration more quickly at the lower dose. The results suggest that novelty-seeking behavior may be a mediator of incentive salience attribution and that incentive salience magnitude may be an indicator of drug reward.

Background Previous studies found that environmental enrichment protects against the initiation of stimulant self-administration in rats, but it is unclear if enrichment also protects against the escalation of stimulant use with long-term exposure. Objective The current study examined the effects of environmental enrichment on escalation of cocaine self-administration using an extended access procedure. Methods Rats were raised from 21 days in an enriched condition (EC) with social cohorts and novel objects, a social condition with only social cohorts (SC), a novelty condition (NC) with novel objects in isolated cages, or an isolated condition (IC) without social cohorts or novel objects. In young adulthood, EC, SC, NC, and IC rats were separated into short access (ShA) or long access (LgA) groups that received either 1- or 6-hr, respectively, of daily cocaine self-administration (0.1 mg/kg/infusion) for 14 days. In a second experiment, EC and IC rats were used to assess differences in acquisition and escalation of cocaine self-administration at a 0.5 mg/kg/infusion unit dose. Results With ShA sessions, EC rats acquired cocaine self-administration at a slower rate than IC rats at both unit doses; however, with extended training, both groups eventually reached similar rates. At the 0.1 mg/kg/infusion dose, only NC and IC rats escalated in amount of intake when switched to the LgA sessions. At the 0.5 mg/kg/infusion dose, rates of cocaine self-administration escalated in LgA groups over 14 days regardless of EC or IC rearing condition; however, EC rats escalated at a faster rate, eventually reaching the same level of intake observed in IC rats. Conclusions Although environmental enrichment protects against escalation of a low unit dose of cocaine, it may not protect against escalation with a higher unit dose. In addition, at a lower unit dose, this protective mechanism appears to be due to the presence of social cohorts rather than novel objects.

Rationale Discounting of delayed and probabilistic reinforcement is linked to increased drug use and pathological gambling. Understanding the neurobiology of discounting is important for designing treatments for these disorders. Glutamate is considered to be involved in addiction-like behaviors; however, the role of ionotropic glutamate receptors (iGluRs) in discounting remains unclear. Objectives The current study examined the effects of N-methyl-D-aspartate (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid (AMPA) glutamate receptor blockade on performance in delay and probability discounting tasks. Methods Following training in either delay or probability discounting, rats (n = 12, each task) received pretreatments of the NMDA receptor antagonists MK-801 (0, 0.01, 0.03, 0.1, or 0.3 mg/kg, s.c.) or ketamine (0, 1.0, 5.0, or 10.0 mg/kg, i.p.), as well as the AMPA receptor antagonist CNQX (0, 1.0, 3.0, or 5.6 mg/kg, i.p.). Hyperbolic discounting functions were used to estimate sensitivity to delayed/probabilistic reinforcement and sensitivity to reinforcer amount. Results An intermediate dose of MK-801 (0.03 mg/kg) decreased sensitivity to both delayed and probabilistic reinforcement. In contrast, ketamine did not affect the rate of discounting in either task but decreased sensitivity to reinforcer amount. CNQX did not alter sensitivity to reinforcer amount or delayed/probabilistic reinforcement. Conclusions These results show that blockade of NMDA receptors, but not AMPA receptors, decreases sensitivity to delayed/probabilistic reinforcement (MK-801) and sensitivity to reinforcer amount (ketamine). The differential effects of MK-801 and ketamine demonstrate that sensitivities to delayed/probabilistic reinforcement and reinforcer amount are pharmacologically dissociable.

Background Social interaction can serve as a natural reward that attenuates drug reward in rats; however, it is unknown if age or housing conditions alter the choice between social interaction and drug. Methods Individually- and pair-housed adolescent and adult rats were tested using conditioned place preference (CPP) in separate experiments in which: (1) social interaction was conditioned against no social interaction; (2) amphetamine (AMPH; 1 mg/kg, s.c.) was conditioned against saline; or (3) social interaction was conditioned against AMPH. Results Social interaction CPP was obtained only in individually-housed adolescents, whereas AMPH CPP was obtained in both individually-housed adolescents and adults; however, the effect of AMPH was not statistically significant in pair-housed adults. When allowed to choose concurrently between compartments paired with either social interaction or AMPH, individually-housed adolescents preferred the compartment paired with social interaction, whereas pair-housed adolescents preferred the compartment paired with AMPH. Regardless of housing condition, adults showed a similar preference for the compartments paired with either social interaction or AMPH. Conclusions Although some caution is needed in interpreting cross-experiment comparisons, the overall results suggest that individually-housed adolescents were most sensitive to the rewarding effect of social interaction, and this hypersensitivity to social reward effectively competed with AMPH reward.