Silencing the α2 subunit of γ-aminobutyric acid type A receptors in rat dorsal root ganglia reveals its major role in antinociception posttraumatic nerve injury.

BACKGROUND: Neuropathic pain (NPP) is likely the result of repetitive high-frequency bursts of peripheral afferent activity leading to long-lasting changes in synaptic plasticity in the spinal dorsal horn. Drugs that promote γ-aminobutyric acid (GABA) activity in the dorsal horn provide partial relief of neuropathic symptoms. The authors examined how in vivo silencing of the GABA receptor type A (GABAA) α2 gene in dorsal root ganglia (DRG) controls NPP. METHODS: After crush injury to the right sciatic nerve of female rats, the α2 GABAA antisense and mismatch oligodeoxynucleotides or NO-711 (a GABA uptake inhibitor) were applied to the L5 DRG. In vivo behavioral assessment of nociception was conducted before the injury and ensuing 10 days (n = 4 to 10). In vitro quantification of α2 GABAA protein and electrophysiological studies of GABAA currents were performed on acutely dissociated L5 DRG neurons at relevant time points (n = 6 to 14). RESULTS: NPP postcrush injury of a sciatic nerve in adult female rats coincides with significant down-regulation of the α2 subunit expression in the ipsilateral DRG (approximately 30%). Selective down-regulation of α2 expression in DRGs significantly worsens mechanical (2.55 ± 0.75 to 5.16 ± 1.16) and thermal (7.97 ± 0.96 to 5.51 ± 0.75) hypersensitivity in crush-injured animals and causes development of significant mechanical (2.33 ± 0.40 to 5.00 ± 0.33) and thermal (10.80 ± 0.29 to 7.34 ± 0.81) hypersensitivity in sham animals (data shown as mean ± SD). Conversely, up-regulation of endogenous GABA via blockade of its uptake in DRG alleviates NPP. CONCLUSION: The GABAA receptor in the DRG plays an important role in pathophysiology of NPP caused by sciatic nerve injury and represents promising target for novel pain therapies.

Autism spectrum disorder in Latin American families: Experiences in Chile.

INTRODUCTION: The present study provides pilot data investigating relationships between severity of autism spectrum disorder (ASD) traits, community supports, and other family variables as reported by caregivers of children with ASD in Chile. METHOD: An anonymous caregiver survey was developed based on previous ASD survey studies conducted in the United States and direct input from collaborators residing in Chile. Participants included Chilean caregivers of individuals with ASD (N = 50; Mchild age = 6.98). The survey addressed topics regarding the child's ASD traits, the caregiver's beliefs and perceptions of ASD, and community supports and engagement. RESULTS: Correlational analyses indicated associations between ASD traits, physician support, family stress, stigma, and community engagement. DISCUSSION: Results from this study highlight the importance of future research to better understand and treat Latin American children with ASD and their families. (PsycINFO Database Record

Cognitive performance enhancement: misuse or self-treatment?

OBJECTIVE: This cross-sectional survey study examines the link between ADHD medication misuse and a positive screen for adult ADHD symptoms. METHOD: Surveys from 184 college student volunteers in Northern Virginia are collected and analyzed. RESULTS: A total of 71% of ADHD stimulant misusers screen positive for ADHD symptoms. Misusers are 7 times more likely to be symptomatic for ADHD than those who do not misuse. Also, 87% of misusers indicate that they do so for academic reasons, and 76% believe that the misuse of the ADHD stimulants improve their grades. CONCLUSION: ADHD stimulant misuse in college students is found to be strongly linked to having symptoms of adult ADHD. The desire for cognitive performance enhancement in college students may be a form of self-treatment for undiagnosed ADHD. College students need more accessibility to medical diagnosis and treatment of adult ADHD to reduce the incidence of misuse in the future.