Neural Predictors of Gait Stability When Walking Freely in the Real-World.

Background: Gait impairments during real-world locomotion are common in neurological diseases. However, very little is currently known about the neural correlates of walking in the real world and on which regions of the brain are involved in regulating gait stability and performance. As a first step to understanding how neural control of gait may be impaired in neurological conditions such as Parkinson’s disease, we investigated how regional brain activation might predict walking performance in the urban environment and whilst engaging with secondary tasks in healthy subjects. Methods: We recorded gait characteristics including trunk acceleration and brain activation in fourteen healthy young subjects whilst they walked around the university campus freely (single task), while conversing with the experimenter and while texting with their smartphone. Neural spectral power density (PSD) was evaluated in three brain regions of interest, namely the pre-frontal cortex (PFC) and bilateral posterior parietal cortex (right/left PPC). We hypothesized that specific regional neural activation would predict trunk acceleration data obtained during the different walking conditions. Results: Vertical trunk acceleration was predicted by gait velocity and left PPC theta (4-7 Hz) band PSD in single-task walking (R-squared = 0.725, p = 0.001) and by gait velocity and left PPC alpha (8-12 Hz) band PSD in walking while conversing (R-squared = 0.727, p = 0.001). Medio-lateral trunk acceleration was predicted by left PPC beta (15-25 Hz) band PSD when walking while texting (R-squared = 0.434, p = 0.010). Conclusions: We suggest that the left PPC may be involved in the processes of sensorimotor integration and gait control during walking in real-world conditions. Frequency-specific coding was operative in different dual tasks and may be developed as biomarkers of gait deficits in neurological conditions during performance of these types of, now commonly undertaken, dual tasks

Proteome modification induced by differential inhibition of MsrA and MsrB in HEK293 cells

11th International Symposium on the Neurobiology and Neuroendocrinology of Aging, Bregenz, AUSTRIA, JUL 29-AUG 03, 2012International audienceno abstrac

EgMYB1, an R2R3 MYB transcription factor from eucalyptus negatively regulates secondary cell wall formation in Arabidopsis and poplar.

• The eucalyptus R2R3 transcription factor, EgMYB1 contains an active repressor motif in the regulatory domain of the predicted protein. It is preferentially expressed in differentiating xylem and is capable of repressing the transcription of two key lignin genes in vivo. • In order to investigate in planta the role of this putative transcriptional repressor of the lignin biosynthetic pathway, we overexpressed the EgMYB1 gene in Arabidopsis and poplar. • Expression of EgMYB1 produced similar phenotypes in both species, with stronger effects in transgenic Arabidopsis plants than in poplar. Vascular development was altered in overexpressors showing fewer lignified fibres (in phloem and interfascicular zones in poplar and Arabidopsis, respectively) and reduced secondary wall thickening. Klason lignin content was moderately but significantly reduced in both species. Decreased transcript accumulation was observed for genes involved in the biosynthesis of lignins, cellulose and xylan, the three main polymers of secondary cell walls. Transcriptomic profiles of transgenic poplars were reminiscent of those reported when lignin biosynthetic genes are disrupted. • Together, these results strongly suggest that EgMYB1 is a repressor of secondary wall formation and provide new opportunities to dissect the transcriptional regulation of secondary wall biosynthesis