To reveal causal connections between brain regions that are specifically modulated by task complexity, we contrasted the performance of right-handed sequential finger movements of different
complexities (simple, scale, complex) that were either pre-learned (memorized) or novel instructed. A complexity-dependent increase in information flow from mesial frontocentral to the left motor cortex and, less pronounced, also to the right motor cortex specifically in the upper alpha range was found. Effective coupling during sequences of high complexity was larger for memorized sequences compared with novel sequences (P = 0.0037). These findings further support the role of mesial frontocentral areas in directing the primary motor cortex in the process Selleck Rapamycin of orchestrating complex movements and in particular learned sequences. “
“Neural stem cells (NSCs) have attracted major research interest due to their potential use in cell replacement therapy. In patients, human cells are the preferred choice, one source of human NSCs being the brain of fetuses.
The aims of the present study were to explore the long-term differentiation, mobility and viability of NSCs derived from the human fetal striatum in response to intracerebral implantation. To investigate long-term spatio-temporal and functional dynamics of grafts in vivo by magnetic resonance imaging, these cells were labeled with superparamagnetic iron oxide (SPIO) nanoparticles prior to implantation. SPIO-labeling of human NSCs left the quantitative profile of the proliferation, cell composition and differentiation
capacity of the cells in vitro unaltered. Also after transplantation, check details the phenotypes after long-term cell differentiation were not significantly different from naïve cells. Upon transplantation, we detected a hypointensity corresponding to the striatal graft location in all animals and persisting for at least 4 months. The hypointense signal appeared visually similar both in location and in volume over time. However, quantitative BCKDHB volumetric analysis showed that the detectable, apparent graft volume decreased significantly from 3 to 16 weeks. Finally, the human NSCs were not proliferating after implantation, indicating lack of tumor formation. These cells are thus a promising candidate for translationally relevant investigations for stem cell-based regenerative therapies. “
“Ghrelin, a hormone produced by the stomach, is generally associated with feeding responses and the regulation of food intake. Recent evidence, however, suggests that ghrelin is also a stress hormone, given that it is released following acute and chronic stressors. The present study examined the role of ghrelin in producing normal metabolic and neurochemical responses to chronic stress. This was achieved by examining these responses in mice with targeted deletions of the ghrelin receptor gene (GHSR KO mice), and comparing them with the same responses in their wild-type (WT) littermates.