Gender differences in the mu rhythm of the human mirror-neuron system

Background

Psychologically, females are usually thought to be superior in interpersonal sensitivity than males. The human mirror-neuron system is considered to provide the basic mechanism for social cognition. However, whether the human mirror-neuron system exhibits gender differences is not yet clear.

Methodology/Principal Findings

We measured the electroencephalographic mu rhythm, as a reliable indicator of the human mirror-neuron system activity, when female (N = 20) and male (N = 20) participants watched either hand actions or a moving dot. The display of the hand actions included androgynous, male, and female characteristics. The results demonstrate that females displayed significantly stronger mu suppression than males when watching hand actions. Instead, mu suppression was similar across genders when participants observed the moving dot and between the perceived sex differences (same-sex vs. opposite-sex). In addition, the mu suppressions during the observation of hand actions positively correlated with the personal distress subscale of the interpersonal reactivity index and negatively correlated with the systemizing quotient.

Conclusions/Significance

The present findings indirectly lend support to the extreme male brain theory put forward by Baron-Cohen (2005), and may cast some light on the mirror-neuron dysfunction in autism spectrum disorders. The mu rhythm in the human mirror-neuron system can be a potential biomarker of empathic mimicry.     

A Locus for Autosomal Dominant Mitral Valve Prolapse on Chromosome 11p15.4

Mitral valve prolapse (MVP) is a common cardiovascular abnormality in the United States, occurring in approximately 2.4% of the general population. Clinically, patients with MVP exhibit fibromyxomatous changes in one or both of the mitral leaflets that result in superior displacement of the leaflets into the left atrium. Although often clinically benign, MVP can be associated with important accompanying sequelae, including mitral regurgitation, bacterial endocarditis, congestive heart failure, atrial fibrillation, and even sudden death. MVP is genetically heterogeneous and is inherited as an autosomal dominant trait that exhibits both sex- and age-dependent penetrance. In this report, we describe the results of a genome scan and show that a locus for MVP maps to chromosome 11p15.4. Multipoint parametric analysis performed by use of GENEHUNTER gave a maximum LOD score of 3.12 for the chromosomal region immediately surrounding the four-marker haplotype D11S4124-D11S2349-D11S1338-D11S1323, and multipoint nonparametric analysis (NPL) confirms this finding (NPL=38.59; P=.000397). Haplotype analysis across this region defines a 4.3-cM region between the markers D11S1923 and D11S1331 as the location of a new MVP locus, MMVP2, and confirms the genetic heterogeneity of this disorder. The discovery of genes involved in the pathogenesis of this common disease is crucial to understanding the marked variability in disease expression and mortality seen in MVP.     

High-performance liquid chromatographic determination of 1-β- -arabinofuranosyl-E-5-(2-bromovinyl)uracil and its metabolite (E)-5-(2-bromovinyl)uracil in serum

A high-performance liquid chromatographic method was developed to assay 1-β- -arabinofuranosyl-E-5-(2-bromovinyl)uracil and its metabolite (E)-5-(2-bromovinyl)uracil in serum. The chloro analogue of the parent drug is used as internal standard. Human serum samples were assayed to establish the pharmacokinetic parameters. Acetonitrile, used as a protein precipitant, was evaporated to dryness and the residue, containing the analytes and internal reference, was dissolved in mobile phase prior to chromatographic analysis. The minimum quantifiable level was 0.02 μg of each analyte per ml of serum.     

Pseudomonas aeruginosa–induced nociceptor activation increases susceptibility to infection

We report a rapid reduction in blink reflexes during in vivo ocular Pseudomonas aeruginosa infection, which is commonly attributed and indicative of functional neuronal damage. Sensory neurons derived in vitro from trigeminal ganglia (TG) were able to directly respond to P. aeruginosa but reacted significantly less to strains of P. aeruginosa that lacked virulence factors such as pili, flagella, or a type III secretion system. These observations led us to explore the impact of neurons on the host’s susceptibility to P. aeruginosa keratitis. Mice were treated with Resiniferatoxin (RTX), a potent activator of Transient Receptor Potential Vanilloid 1 (TRPV1) channels, which significantly ablated corneal sensory neurons, exhibited delayed disease progression that was exemplified with decreased bacterial corneal burdens and altered neutrophil trafficking. Sensitization to disease was due to the increased frequencies of CGRP-induced ICAM-1⁺ neutrophils in the infected corneas and reduced neutrophil bactericidal activities. These data showed that sensory neurons regulate corneal neutrophil responses in a tissue-specific matter affecting disease progression during P. aeruginosa keratitis. Hence, therapeutic modalities that control nociception could beneficially impact anti-infective therapy.     

Health Risk Assessment of Petrol Station Workers in the Inner City of Bangkok,Thailand, to the Exposure to BTEX and Carbonyl Compounds by Inhalation

The occupational health risk of petrol station workers from exposure to BTEX and carbonyl compounds via inhalation was estimated in the inner city of Bangkok. Personal sampling was performed within the workers’ breathing zone using 2,4 dinitrophenylhydrazine cartridges and charcoal glass tubes connected to a personal air pump during eight working hours at six petrol stations. BTEX and carbonyl compounds were quantitatively analyzed by GC/FID and HPLC/UV, respectively. Of all detectable BTEX and carbonyl compounds, the levels of the four most prevalent compounds (benzene, ethylbenzene, formaldehyde, and acetaldehyde) were used to assess the lifetime cancer risk and 95% confidence interval of the risk levels were found to be totally higher than acceptable criteria for benzene (1.82 × 10^–4–2.50 × 10^–4), formaldehyde (7.81 × 10^–6–1.04 × 10^–5), ethylbenzene (4.11 × 10^–6–5.52 × 10^–6), and acetaldehyde (1.39 × 10^–6–2.45 × 10^–6). Thus, petrol station workers in the inner city of Bangkok have a potentially high cancer risk through inhalation exposure. With respect to the noncarcinogenic agents, toluene, m,p-xylene, o-xylene, and propionaldehyde, all non-cancer health risk were within hazard quotients of 1 and of acceptable risk.     

Complementary Treatment of the Common Cold and Flu with Medicinal Plants – Results from Two Samples of Pharmacy Customers in Estonia

The aim of the current survey was to investigate the complementary self-treatment of the common cold and flu with medicinal plants among pharmacy customers in Estonia. A multiple-choice questionnaire listing 10 plants and posing questions on the perceived characteristics of cold and flu, the effectiveness of plants, help-seeking behaviour, self-treatment and sources of information, was distributed to a sample of participants in two medium size pharmacies. The participants were pharmacy customers: 150 in Tallinn (mostly Russian speaking) and 150 in Kuressaare (mostly Estonian speaking). The mean number of plants used by participants was 4.1. Of the respondents, 69% self-treated the common cold and flu and 28% consulted with a general practitioner. In general, medicinal plants were considered effective in the treatment of the above-mentioned illnesses and 56% of the respondents had used exclusively medicinal plants or their combination with OTC medicines and other means of folk medicine for treatment. The use of medicinal plants increased with age and was more frequent among female than male respondents. Among Estonian-speaking customers lime flowers, blackcurrant and camomile were more frequently used, and among Russian speaking customers raspberry and lemon fruits. Regardless of some statistically significant differences in preferred species among different age, education, sex and nationality groups, the general attitude towards medicinal plants for self-treatment of the common cold and flu in Estonia was very favourable.