Functional amyloids have been identified in nearly all facets of cellular life, with microbial functional amyloids leading the way. Unlike disease-associated amyloids, functional amyloids are assembled by dedicated, directed pathways and ultimately perform a physiological function that benefits the organism. The evolved amyloid assembly and disassembly pathways of microbes have provided novel insights into how cells have harnessed the amyloid assembly process for productive means. An understanding of functional amyloid biogenesis promises to provide a fresh perspective on the molecular events that underlie disease-associated
amyloidogenesis. Here, we review functional microbial amyloids with an emphasis on curli fibers and their role in promoting biofilm formation and other community behaviors.”
“Exposure of the fetal brain to ionizing radiation causes this website congenital brain 4SC-202 nmr abnormalities. Normal brain formation requires regionally and temporally appropriate proliferation and differentiation of neural stem cells (NSCs) into neurons and glia. Here, we investigated the effects of X-irradiation on proliferating homogenous NSCs prepared from mouse ES cells. Cells irradiated with X-rays at a dose of 1 Gy maintained the capabilities for proliferation and differentiation but stopped proliferation temporarily. In contrast, the cells ceased proliferation following irradiation
at a dose of >5 Gy. These results suggest that irradiation of the fetal brain at relatively low doses may cause congenital brain abnormalities as with relatively high doses. (C) 2012 Elsevier Ireland Ltd and the Japan Dehydratase Neuroscience Society. All rights reserved.”
“Chronic stress perturbs modulatory brain neurotransmitter systems, including serotonin (5-HT), and is a risk factor for psychiatric disorders such as depression. Deficits in cognitive flexibility, reflecting prefrontal cortical dysfunction, are prominent in such disorders. Orbitofrontal cortex (OFC) has been implicated specifically in reversal learning, a form of cognitive flexibility modulated by 5-HT.
The objectives of the study were (1) to assess the effects of chronic intermittent cold (CIC) stress,
a potent metabolic stressor, on performance of rats in an attentional set-shifting test (AST), and (2) to assess a possible role for serotonin in CIC-induced deficits and test the effects of acute serotonin reuptake blockade.
Male Sprague-Dawley rats were exposed to CIC stress (14 days x 6 h/day at 4A degrees C) before testing on the AST. In subsequent experiments, brain 5-HT was depleted in na < ve rats with para-chlorophenylalanine or 5-HT release was increased acutely in CIC-stressed rats with citalopram (5 mg/kg, s.c.) given 30 min prior to the first reversal task. Microdialysis was used to assess CIC-induced changes in 5-HT release in OFC during testing.
CIC-stressed rats exhibited a selective impairment on the first reversal task in the AST.