Group 3 sigma factor gene, sigJ, a key regulator of desiccation tolerance, regulates the synthesis of extracellular polysaccharide in cyanobacterium Anabaena sp. strain PCC 7120

The changes in the expression of sigma factor genes during dehydration in terrestrial Nostoc HK-01 and aquatic Anabaena PCC 7120 were determined. The expression of the sigJ gene in terrestrial Nostoc HK-01, which is homologous to sigJ (alr0277) in aquatic Anabaena PCC 7120, was significantly induced in the mid-stage of dehydration. We constructed a higher-expressing transformant of the sigJ gene (HE0277) in Anabaena PCC 7120, and the transformant acquired desiccation tolerance. The results of Anabaena oligonucleotide microarray experiments showed that a comparatively large number of genes relating to polysaccharide biosynthesis were upregulated in the HE0277 cells. The extracellular polysaccharide released into the culture medium of the HE0277 cells was as much as 3.2-fold more than that released by the control cells. This strongly suggests that the group 3 sigma factor gene sigJ is fundamental and conducive to desiccation tolerance in these cyanobacteria

The Effect of Negative and Positive Emotionality on Associative Memory: An fMRI Study

In general, emotion is known to enhance memory processes. However, the effect of emotion on associative memory and the underling neural mechanisms remains largely unexplored. In this study, we explored brain activation during an associative memory task that involved the encoding and retrieval of word and face pairs. The word and face pairs consisted of either negative or positive words with neutral faces. Significant hippocampal activation was observed during both encoding and retrieval, regardless of whether the word was negative or positive. Negative and positive emotionality differentially affected the hemodynamic responses to encoding and retrieval in the amygdala, with increased responses during encoding negative word and face pairs. Furthermore, activation of the amygdala during encoding of negative word and neutral face pairs was inversely correlated with subsequent memory retrieval. These findings suggest that activation of the amygdala induced by negative emotion during encoding may disrupt associative memory performance

The Neurocognitive Effects of Aripiprazole Compared with Risperidone in the Treatment of Schizophrenia

Aripiprazole is a D2 and D3 receptor partial agonist that is unlike other second generation antipsychotics. The effectiveness of aripiprazole with regard to neurocognitive function and its adverse effects is unclear. The present study evaluates the comparative efficacy, effects on neurocognitive function, and adverse effects of aripiprazole and risperidone in the treatment of hospitalized patients with schizophrenia. This double-blind, cross-over study included 23 patients with schizophrenia who were randomly assigned to be treated first with either aripiprazole or risperidone. After eight weeks on one medication, the patients were switched to the other medication for eight weeks. The patient assessment included the Positive and Negative Syndrome Scale (PANSS), neurocognitive assessments, and adverse events including extrapyramidal symptoms, vital signs, electrocardiogram, and clinical laboratory tests. The study findings indicated that psychopathology assessed with the PANSS, extrapyramidal symptoms and other adverse effects did not differ between aripiprazole and risperidone for the subjects remaining in treatment. In the neurocognitive assessments, the score for disinhibition with aripiprazole was significantly lower than with risperidone (p<0.05). In addition, serum prolactin levels were significantly lower with aripiprazole (p<0.001). The treatment drop-out rate was higher for patients receiving aripiprazole than risperidone. In comparing aripiprazole and risperidone, risperidone is better from the viewpoint of treatment continuation. On the other hand, some adverse effects, such as hyperprolactinemia and disinhibition, are less severe with aripiprazole. Thus, for certain applications, aripiprazole may be a beneficial new treatment option for schizophrenia

Correlation between amygdala activation and associative memory performance.

<p>A. shows the graph illustrates the inverse correlation between correct response rate of negative word - face pairs and the contrast estimates during encoding of negative word - face pairs in the region of interest shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0024862#pone-0024862-g002" target="_blank">Figure 2A</a>. B. shows the graph illustrates the positive correlation between correct response rate of positive word - face pairs and the contrast estimates during encoding of positive word - face pairs in the region of interest shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0024862#pone-0024862-g002" target="_blank">Fig. 2A</a>.</p