In contrast, repulsive shifts are caused solely by response depression on the adapted flank. We suggest that an early mechanism leads to repulsive shifts while attractive shifts engage a subsequent late facilitation. A potential role for attractive shifts may be improved stimulus discrimination around the adapting orientation. (C) 2009 IBRO. Published by Elsevier Ltd. All rights reserved.”
“Regulation of periciliary liquid (PCL) depth is of central importance to mucociliary clearance by the airway epithelium. Without adequate hydration mucociliary Sotrastaurin transport would cease, leading to build up of mucus

in the airways, and impairing the clearance of any trapped inhaled particulates. Airway epithelial cells are known to release ATP under a number of stress conditions. Cell surface receptors bind ATP and trigger an intracellular calcium response

which regulates the gating of specific ion channels on the apical and basolateral cell membranes. This shifts the electrochemical balance, resulting in the accumulation of Na(+) and Cl(-) in the periciliary liquid, and providing an osmotic driving force for water flux. In this study, we present a mathematical model of a single airway epithelial cell which describes the fluid secretion elicited after a rise in intracellular calcium. The model provides a basis to quantitatively analyse selleck products the influence of intracellular calcium signalling on fluid movement. The model demonstrates behaviour consistent with a number of experimental data on manipulating periciliary liquid volume and tonicity, and provides a quantitative

basis for analysing the role of the different membrane ion channels in determining water flux following different physiological stimuli. (C) 2009 Elsevier Ltd. eFT-508 in vitro All rights reserved.”
“Coordinated eye-head gaze shifts have been evoked during electrical stimulation of the frontal cortex (supplementary eye field (SEF) and frontal eye field (FEF)) and superior colliculus (SC), but less is known about the role of lateral intraparietal cortex (LIP) in head-unrestrained gaze shifts. To explore this, two monkeys (M1 and M2) were implanted with recording chambers and 3-D eye+ head search coils. Tungsten electrodes delivered trains of electrical pulses (usually 200 ms duration) to and around area LIP during head-unrestrained gaze fixations. A current of 200 mu A consistently evoked small, short-latency contralateral gaze shifts from 152 sites in M1 and 243 sites in M2 (Constantin et al., 2007). Gaze kinematics were independent of stimulus amplitude and duration, except that subsequent saccades were suppressed. The average amplitude of the evoked gaze shifts was 8.46 degrees for M1 and 8.25 degrees for M2, with average head components of only 0.36 and 0.62 degrees respectively. The head’s amplitude contribution to these movements was significantly smaller than in normal gaze shifts, and did not increase with behavioral adaptation.