Sex difference in the effect of environmental enrichment on food restriction-induced persistence of cocaine conditioned place preference and mechanistic underpinnings.

Psychosocial and environmental factors, including loss of natural reward, contribute to the risk of drug abuse. Reward loss has been modeled in animals by removal from social or sexual contact, transfer from enriched to impoverished housing, or restriction of food. We previously showed that food restriction increases the unconditioned rewarding effects of abused drugs and the conditioned incentive effects of drug-paired environments. Mechanistic studies provided evidence of decreased basal dopamine (DA) transmission, adaptive upregulation of signaling downstream of D1 DA receptor stimulation, synaptic upscaling and incorporation of calcium-permeable AMPA receptors (CP-AMPARs) in medium spiny neurons (MSNs) of nucleus accumbens (NAc). These findings align with the still evolving 'reward deficiency' hypothesis of drug abuse. The present study tested whether a compound natural reward that is known to increase DA utilization, environmental enrichment, would prevent the persistent expression of cocaine conditioned place preference (CPP) otherwise observed in food restricted rats, along with the mechanistic underpinnings. Because nearly all prior investigations of both food restriction and environmental enrichment effects on cocaine CPP were conducted in male rodents, both sexes were included in the present study. Results indicate that environmental enrichment curtailed the persistence of CPP expression, decreased signaling downstream of the D1R, and decreased the amplitude and frequency of spontaneous excitatory postsynaptic currents (EPSCs) in NAc MSNs of food restricted male, but not female, rats. The failure of environmental enrichment to significantly decrease food restriction-induced synaptic insertion of CP-AMPARs, and how this may accord with previous pharmacological findings that blockade of CP-AMPARs reverses behavioral effects of food restriction is discussed. In addition, it is speculated that estrous cycle-dependent fluctuations in DA release, receptor density and MSN excitability may obscure the effect of increased DA signaling during environmental enrichment, thereby interfering with development of the cellular and behavioral effects that enrichment produced in males.

Multifunctional aqueous polyurethanes with high strength and self-healing efficiency based on silver nanowires for flexible strain sensors.

Advanced sensor technology is widely applied in human motion monitoring and research. However, it often encounters problems such as scratches, fractures, and aging, which affect its lifespan and reliability. To address these challenges, we draw inspiration from the inherent self-healing properties of organic biological entities in nature to endow our sensors with self-healing capability. In this work, we constructed a reversible multi-hydrogen-bonded physical crosslinking network and introduced aromatic disulfide bonds into the polyurethane backbone. This design not only achieves a very high mechanical strength of the material, but also efficient self-healing properties. At 80 °C, the tensile strength of the WPU-U2D1 material reached 28.88 MPa, with a fracture elongation of 748.64%, and a self-healing efficiency as high as 99.24%. Based on this material, we successfully prepared a flexible conductive composite film (WPU@AgNW) and applied it to flexible strain sensors. The sensor demonstrated excellent sensitivity and reliability in human motion monitoring (electrical conductivity of 2.66 S cm-1), which provides a new idea for realising the breakthrough of high-performance flexible sensors. These outstanding properties makes it have great potential for application in flexible wearable devices, human-computer interaction, bionic electronic devices and other fields.

Comparison of Pain in Male Drug Rehabilitees with and without Human Immunodeficiency Virus in Yunnan Province, China.

BACKGROUND The purpose of this study was to compare pain symptoms in drug rehabilitees with or without human immunodeficiency virus (HIV) in Yunnan Province, China. MATERIAL AND METHODS This was a retrospective single-center cohort study. A total of 120 male substance users, including 65 with HIV, were enrolled after admission to the Fifth Drug Rehabilitation Center in Yunnan Province. Individuals who were >18 years of age and who had illicit drugs detected in their urine, despite not having used drugs for at least 2 months, were included. The patients evaluated their average pain intensity for the previous 4 weeks using a visual analog scale. PainDETECT questionnaire scores were used to classify pain into nociceptive and mixed component subgroups. Sleep quality was also evaluated using the Pittsburgh Sleep Quality Index scale. RESULTS The prevalence and intensity of the pain symptoms were higher for the drug rehabilitees with HIV than for those without HIV. Moreover, the rehabilitees with HIV were more likely to experience neuropathic and nociceptive pain, whereas those without HIV reported only nociceptive pain. The sleep quality of the rehabilitees with HIV was also lower, regardless of the pain symptoms. CONCLUSIONS Our results showed that the drug rehabilitees with HIV in Yunnan Province, China, experienced more frequent and stronger pain (both nociceptive and neuropathic) than those without HIV. They also experienced poorer sleep quality, although it was unrelated to pain. Our results provide data to support clinical diagnosis and treatment.