1. The release of ink in response to a noxious stimulus is a relatively stereotyped behavior produced by strong and long-lasting stimuli. The purpose of this series of papers is to determine the quantitative extent to which the known voltage- and time-dependent ionic conductance mechanisms and synaptic influences can account for the ink gland motor neurons' firing pattern and, thus, the feature...

Tight junctions regulate paracellular conductance and ionic selectivity. These properties vary among epithelia but the molecular basis of this variation remains unknown. To test whether members of the claudin family of tight junction proteins influence paracellular ionic selectivity, we expressed human claudin-4 in cultured MDCK cells using an inducible promoter. Overexpression increased the co...

Postsynaptic integration is a complex function of passive membrane properties and nonlinear activation of voltage-gated channels. Some cortical neurons express many voltage-gated channels, with each displaying heterogeneous dendritic conductance gradients. This complexity has hindered the construction of experimentally based mechanistic models of cortical neurons. Here we show that it is possib...

Unlike biological protein pores in lipid membranes, nanopores fabricated in synthetic materials can withstand a wide range of environmental conditions including the presence of organic solvents. This capability expands the potential of synthetic nanopores to monitor chemical reactions occurring at the interface between solutions of organic and aqueous character. In this work, nanopores fabricat...

The conductance of ion channels can be modulated by a transmembrane potential difference, due to alterations on ion-mobility and also by changes in the pore structure. Despite the vast knowledge regarding the influence of voltage on transport properties of ion channels, little attention has been paid to describe, with atomic detail, the modulation of ionic transport in gap-junction channels (GJ...

1 Introduction 1 Theory of specific conductance 1 Electrical resistance and conductance 1 Definition of conductivity 2 Potassium chloride secondary standards 2 Temperature effects and instrumental temperature compensation 3 Ionic conductance 6 Concentration relationships 7 Temperature relationships 8 Effects of complexation and protonation 9 Applications to analytical quality control 10 An empi...

This thesis consists of two manuscripts: “Exploring voltage-dependent ion channels in silico by hysteretic conductance” by Tom Andersson, and “Statistical sensitivity analysis and remodeling of whole-cell conductances in nociceptors” by Tom Andersson, Joanna Tyrcha and Olivia Eriksson. The general approach to modeling neuronal excitability is to formalize and simulate systems of ordinary differ...

The rodent vestibular system is immature at birth. During the first postnatal week, vestibular type I and type II hair cells start to acquire their characteristic morphology and afferent innervation. We have studied postnatal changes in the membrane properties of type I hair cells acutely isolated from the semicircular canals (SCC) of gerbils and rats using whole cell patch clamp and report for...

Aquaporins (AQPs) in the major intrinsic family of proteins mediate fluxes of water and other small solutes across cell membranes. AQP1 is a water channel, and under permissive conditions, a nonselective cation channel gated by cGMP. In addition to mediating fluid transport, AQP1 expression facilitates rapid cell migration in cell types including colon cancers and glioblastoma. Work here define...