(c) 2008 Elsevier Ltd. All rights reserved.”
“Current theories of orbitofrontal cortex (OFC) function suggest that this region should participate in the generation of error-related signals associated with the outcomes of actions. We investigated the impact of lesions to OFC on the error-related negativity (ERN), an electrophysiological marker of performance monitoring. Four OFC patients and eight control subjects participated in a manual Stroop task while brain electrical activity was recorded. We found check details that the ERN was attenuated

in the patient group. Three of the patients also had impaired error correction performance, but all showed normal post-error slowing. These findings suggest OFC involvement in monitoring and

evaluation of ongoing performance. Published by Elsevier Ireland Ltd.”
“Considerable insight into intracellular Ca2+ responses has been obtained through the development of whole cell models that are based on molecular mechanisms, e.g., single channel buy GSK1838705A kinetics of the inositol 1,4,5-trisphosphate (IP3) receptor Ca2+ channel. However, a limitation of most whole cell models to date is the assumption that IP3 receptor Ca2+ channels (IP(3)Rs) are globally coupled by a “”continuously stirred”" bulk cytosolic [Ca2+], when in fact open IP(3)Rs experience elevated “”domain”" Ca2+ concentrations. Here we present a 2N + 2-compartment whole cell model of local and global Ca2+ responses mediated by N = 100, 000 diffusely distributed IP(3)Rs, each represented by a four-state Markov chain. Two of these compartments Endocrinology inhibitor correspond to bulk cytosolic and luminal Ca2+

concentrations, and the remaining 2N compartments represent time-dependent cytosolic and luminal Ca2+ domains associated with each IP3R. Using this Monte Carlo model as a starting point, we present an alternative formulation that solves a system of advection-reaction equations for the probability density of cytosolic and luminal domain [Ca2+] jointly distributed with IP3R state. When these equations are coupled to ordinary differential equations for the bulk cytosolic and luminal [Ca2+], a realistic but minimal model of whole cell Ca2+ dynamics is produced that accounts for the influence of local Ca2+ signaling on channel gating and global Ca2+ responses. The probability density approach is benchmarked and validated by comparison to Monte Carlo simulations, and the two methods are shown to agree when the number of Ca2+ channels is large (i.e., physiologically realistic).