In this work we analyzed these features by considering the approach proposed by the self-organized criticality theory: we found that networks of dissociated cortical neurons also generate spontaneous

events of spreading C646 in vivo activity, previously observed in cortical slices, in the form of neuronal avalanches. Choosing an appropriate time scale of observation to detect such neuronal avalanches, we studied the dynamics by considering the spontaneous activity during acute recordings in mature cultures and following the development of the network. We observed different behaviors, i.e. sub-critical, critical or super-critical distributions of avalanche sizes and durations, depending on both the age and the development of cultures. In order to clarify this variability, neuronal avalanches were correlated with other statistical parameters describing the global activity of the network. Criticality was found in correspondence to medium synchronization among bursts and high ratio between bursting and spiking activity. Then, the action of specific drugs affecting global

bursting dynamics (i.e. acetylcholine and bicuculline) was investigated to confirm the correlation between criticality and regulated balance between synchronization and variability in the bursting activity. Finally, a computational model of neuronal network was developed in order to interpret the experimental results and understand which parameters (e.g. connectivity, excitability) influence the

distribution of avalanches.

In summary, cortical neurons preserve Galunisertib solubility dmso their capability to self-organize in an effective network even when dissociated and cultured in vitro. The distribution of avalanche features seems to be critical in those cultures displaying medium synchronization among bursts and poor random spiking activity, as confirmed by chemical manipulation experiments and modeling studies. (C) 2008 IBRO. Published by Elsevier Ltd. All rights reserved.”
“The main protease (M-pro) of severe acute respiratory syndrome coronavirus (SARS-CoV) plays an essential role in the extensive proteolytic processing of the viral polyproteins (pp1a and pp1ab), and it is an important target for anti-SARS drug development. click here It was found that SARS-CoV M-pro exists in solution as an equilibrium of both monomeric and dimeric forms, and the dimeric form is the enzymatically active form. However, the mechanism of SARS-CoV M-pro dimerization, especially the roles of its N-terminal seven residues (N-finger) and its unique C-terminal domain in the dimerization, remain unclear. Here we report that the SARS-CoV M-pro C-terminal domain alone (residues 187 to 306; M-pro-C is produced in Escherichia coli in both monomeric and dimeric forms, and no exchange could be observed between them at room temperature. The M-pro-C dimer has a novel dimerization interface.