These findings indicate a less flexible and overly constrained visuomotor system in WS, which is consistent with more widespread and diffuse abnormalities in parietal and cerebellar regions. (C) 2011 IBRO. Published by Elsevier Ltd. All rights reserved.”
“In this paper we introduce a continuous time stochastic selleck compound neurite branching model closely related to the discrete time stochastic BES-model. The discrete time BES-model is underlying current attempts to simulate cortical development, but is difficult to analyze. The new continuous time formulation facilitates analytical treatment thus allowing us to examine the structure of the model more closely.
We derive explicit expressions for the time dependent probabilities p(gamma, t) for finding a tree gamma at time t, valid for arbitrary continuous time branching models with tree and segment dependent branching rates. find more We show, for the specific case of the continuous time BES-model, that as expected from our model formulation, the sums needed to evaluate expectation values of functions of the terminal segment number mu(f(n),t) do
not depend on the distribution of the total branching probability over the terminal segments. In addition, we derive a system of differential equations for the probabilities p(n,t) of finding it terminal segments at time t. For the continuous BES-model, this system of differential equations gives direct numerical access to functions only depending on the number of terminal segments, and we use this to evaluate the development of the mean and standard deviation of the number of terminal segments at a time t. For comparison we discuss two cases where mean and variance of the number of Tacrolimus (FK506) terminal segments are exactly solvable. Then we discuss the numerical evaluation of the S-dependence of the solutions for the continuous
time BES-model. The numerical results show clearly that higher S values, i.e. values such that more proximal terminal segments have higher branching rates than more distal terminal segments, lead to more symmetrical trees as measured by three tree symmetry indicators. (C) 2011 Elsevier Ltd. All rights reserved.”
“Food restriction (FR) decreases brain-derived neurotrophic factor (BDNF) expression in hypothalamic and hindbrain regions that regulate feeding and metabolic efficiency, while increasing expression in hippocampal and neocortical regions. Drugs of abuse alter BDNF expression within the mesocorticolimbic dopamine (DA) pathway, and modifications of BDNF expression within this pathway alter drug-directed behavior. Although FR produces a variety of striatal neuroadaptations and potentiates the rewarding effects of abused drugs, the effects of FR on BDNF expression and function within the DA pathway are unknown.