Rhythmic TMS as a Feasible Tool to Uncover the Oscillatory Signatures of Audiovisual Integration

Multisensory integration is quintessential to adaptive behavior, with clinical populations showing significant impairments in this domain, most notably hallucinatory reports. Interestingly, altered cross-modal interactions have also been reported in healthy individuals when engaged in tasks such as the Sound-Induced Flash-Illusion (SIFI). The temporal dynamics of the SIFI have been recently tied to the speed of occipital alpha rhythms (IAF), with faster oscillations entailing reduced temporal windows within which the illusion is experienced. In this regard, entrainment-based protocols have not yet implemented rhythmic transcranial magnetic stimulation (rhTMS) to causally test for this relationship. It thus remains to be evaluated whether rhTMS-induced acoustic and somatosensory sensations may not specifically interfere with the illusion. Here, we addressed this issue by asking 27 volunteers to perform a SIFI paradigm under different Sham and active rhTMS protocols, delivered over the occipital pole at the IAF. Although TMS has been proven to act upon brain tissues excitability, results show that the SIFI occurred for both Sham and active rhTMS, with the illusory rate not being significantly different between baseline and stimulation conditions. This aligns with the discrete sampling hypothesis, for which alpha amplitude modulation, known to reflect changes in cortical excitability, should not account for changes in the illusory rate. Moreover, these findings highlight the viability of rhTMS-based interventions as a means to probe the neuroelectric signatures of illusory and hallucinatory audiovisual experiences, in healthy and neuropsychiatric populations

The Role of Alpha Oscillations among the Main Neuropsychiatric Disorders in the Adult and Developing Human Brain: Evidence from the Last 10 Years of Research

Alpha oscillations (7–13 Hz) are the dominant rhythm in both the resting and active brain. Accordingly, translational research has provided evidence for the involvement of aberrant alpha activ- ity in the onset of symptomatological features underlying syndromes such as autism, schizophrenia, major depression, and Attention Deficit and Hyperactivity Disorder (ADHD). However, findings on the matter are difficult to reconcile due to the variety of paradigms, analyses, and clinical phenotypes at play, not to mention recent technical and methodological advances in this domain. Herein, we seek to address this issue by reviewing the literature gathered on this topic over the last ten years. For each neuropsychiatric disorder, a dedicated section will be provided, containing a concise account of the current models proposing characteristic alterations of alpha rhythms as a core mechanism to trigger the associated symptomatology, as well as a summary of the most relevant studies and scientific con- tributions issued throughout the last decade. We conclude with some advice and recommendations that might improve future inquiries within this field

The Effects of Arousal and Inhibition on Joke Rating

On the basis of the studies conducted by Clark, (1952), and Martin, (1964), it has been demonstrated that sexual arousal and inhibition could be produced experimentally. The purpose of this study was to empirically investigate the effects of sexual arousal and inhibition on the ratings of jokes. The study was conducted to add to the general body of scientific knowledge and at the same time add additional data for the purpose of standardization on Form B of the IPAT Humor Test. There were 64 single, male, undergraduate, volunteer students from General Psychology I discussion groups used as subjects for the experiment. The mean age was 18.7. Subjects in the study were randomly assigned to one of four experimental treatment groups: Permissive Arousal (PA), Inhibited Arousal (IA), Permissive Neutral (PN) or Inhibited Neutral (IN). The procedure used was to have subjects come in and individually be administered Form A or Form B of the IPAT. They were then instructed to return the following week for completion of the study. Upon their return, the following week, the subjects were asked if they would take a few minutes to participate in an additional study, unrelated to the one they had been participating in; all subjects agreed and at this point the experimental treatment was administered. One half of the subjects were then treated in a permissive or relaxed manner and were perm1tted to engage in a friendly discussion over familiar subjects. Inhibition was produced in the other half of the subjects by treat1ng them in a formal manner and causing them to reflect on parental attitudes. One half of each of these groups was then assigned to either a high or low arousal condition. High arousal treatment consisted of viewing and rating slides of attractive nude females while low arousal consisted of rating neutral slides of landscapes, architecture, or abstracts. The results indicate that both the arousal and inhibition treatment were effective. This was reflected in the differences as to the number of slides viewed and significance on the basis of an analysis of variance. The effect of the treatments was not, however, reflected in the IPAT test scores. The reason for this is probably best explained in terms of heterogeneity of subjects as to level sex drive in the groups. For example, the permissive arousal group appears to have been heavily populated with subjects having low sex drive as measured by the Epstein, (1957), Orgasm Scale. A significant result was found on Factor IV of the IPAT which reflected a general overall change in attitude toward the playfulness and away from gruesomeness. This was interpreted in terms of what may be called rapport or the subjects’ familiarity with the test situation. Finally, no significant difference was found between the two forms of the IPAT. For this reason, on the basis of this study, the forms probably can be considered as equivalent in future research

In the search for stroke genes: a long and winding road

In spite of a significant improvement in control of numerous predisposing risk factors, stroke remains a major health problem and a common cause of death and disability in our societies. Genetic predisposition to stroke development exists and has been documented in both animal models and in humans. However, a precise definition of genetic factors responsible for common forms of stroke is still lacking, mainly due to its complex nature, the confounding presence of other predisposing risk factors, and the genetic heterogeneity of human populations. In contrast, important breakthroughs have been reached for monogenic forms of stroke, such as cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). An animal model of stroke, the stroke-prone spontaneously hypertensive rat, has provided valuable information on genetic factors involved in stroke predisposition. Among them, the gene-encoding atrial natriuretic peptide has been identified as a stroke gene in both the stroke-prone spontaneously hypertensive rat and, subsequently, in two different human populations. In particular, structural alterations of the gene are consistently present in diseased individuals, suggesting an important role of mutation-dependent mechanisms in stroke predisposition. Finally, the recent use of intermediate disease phenotypes provides a reductionist approach that may contribute to important accumulating information on genes contributing to cerebrovascular accidents. (C) 2004 American Journal of Hypertension, Ltd

Effect of Ethyl Acetate Extract of Sea Pen Virgularia Gustaviana on Viability of Cancer Cells

BACKGROUND AND OBJECTIVE: Due to high cancer incidence rate and become resistant to chemical drugs and their side effects make it necessary to research on new natural compounds. Sea pen with special chemical compounds with anti-cancer effects have been considered in recent years. In this study, extraction of chemical compounds from marine sea pen Virgularia gustaviana and their effect on cancer cells were investigated. METHODS: In this study the ethyl acetate extract of Virgularia gustaviana was separated by silica gel column chromatography. The column was washed with N-hexane 100% and N-hexane-ethyl acetate solvent at ratio of 9:1 to 1:9. Thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) was used for qualitative identification of seven fractions. Viability of HeLa cancer cells was investigated using MTT assay at the concentration of 25, 50 and a 100 &micro;l/ml compounds. FINDINGS: MTT assay showed that G fraction, dose-dependently decreased cell viability of cells and the most effective concentration was 100 &micro;l (with viability 6.33&plusmn;2.02% of cancer cells) which was significantly less than control group (p<0.05). Retention time of G fraction in HPLC graph was similar to Cembrane Diterpene isolated from Sarcophyton.&nbsp; CONCLUSION: The results of the studyshowed that compounds extracted from Virgularia gustaviana inhibit the growth of cancer cells and further research will be required to examine the mechanism of effec

Macrolide Resistance in Streptococcus pneumoniae in Hong Kong

Erythromycin resistance rates among penicillin-susceptible Streptococcus pneumoniae were 38 and 92% among penicillin-intermediate and -resistant S. pneumoniae isolates from Hong Kong, respectively, and 27% (43 of 158) of the isolates showed the MLS(B) phenotype, and the majority carried the ermB gene; 73% (115 of 158) displayed the M phenotype, and all possessed the mef gene. The MLS(B) phenotype was predominant in penicillin-susceptible, macrolide-resistant isolates and in penicillin-nonsusceptible isolates of serotype 6B, whilst the M phenotype was predominant in penicillin-intermediate or -resistant isolates belonging to serotype 23F or 19F. Extensive spread of clones of drug-resistant pneumococci has led to the widespread presence of macrolide resistance in S. pneumoniae in Hong Kong