Sökning: "voltage clamp"

Visar resultat 16 - 20 av 40 avhandlingar innehållade orden voltage clamp.

1. 16. Applying the Pump and Leak Hypothesis. An experimental and theoretical investigation of the principles of ion regulation and excitability in the crustacean stretch receptor neuron

   Författare :Sten Theander; Människan i rörelse: hälsa och rehabilitering; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Neurology; neuropsychology; lobster; stretch receptor neuron; leak current; Q-current; K-Cl cotransporter; A-current; mathematical model; excitability; GABA channel; neurophysiology; ion regulation; neuropsykologi; Neurologi; neurofysiologi;

   Sammanfattning : An invertebrate nerve cell preparation, the lobster stretch receptor neuron, was investigated with respect to maintenance of its resting voltage, intracellular ion concentrations and excitability using voltage clamp technique and ion-selective microelectrodes. It was found that the resting voltage (-65 mV) of microelectrode impaled cells is caused by (a) a homogenous population of K+ channels which we denoted as leak channels (b) an electrogenic and voltage-dependent Na-K pump current and (c) an inward microelectrode-induced "impalement" current carried mainly by Na+. LÄS MER

3. 17. Molecular Mechanisms of Resin Acids and Their Derivatives on the Opening of a Potassium Channel

   Författare :Nina Ottosson; Fredrik Elinder; David Engblom; Bertil Hille; Linköpings universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES;

   Sammanfattning : Voltage-gated ion channels play fundamental roles in excitable cells, such as neurons, where they enable electric signaling. Normally, this signaling is well controlled, but brain damage, alterations in the ionic composition of the extracellular solution, or dysfunctional ion channels can increase the electrical excitability thereby causing epilepsy. LÄS MER

4. 18. Electrophysiology-based investigations of G protein-coupled receptor pharmacology

   Författare :Richard Ågren; Karolinska Institutet; Karolinska Institutet; []
   Nyckelord :;

   Sammanfattning : G protein-coupled receptors (GPCRs) constitute targets for ~34% of approved drugs. The muscarinic acetylcholine M2 receptor (M2R) activates G protein-coupled receptor inward rectifying potassium (GIRK) channels in the central nervous system and heart. Membrane potential modulates agonist potency at several GPCRs. LÄS MER

5. 19. Ion Transport in Glial and Neuroblastoma Cells

   Författare :Sonya K. A. Juthberg; Linköpings universitet; []
   Nyckelord :MEDICINE; MEDICIN;

   Sammanfattning : The aim of this thesis has been to increase our understanding of the ion channel function and the ion transport mechanisms in glial cells. The analysis has also covered Na channel function in human neuroblastoma cells in order to get a basis for similar studies of glial cells In paper I isotopes 42K and 201 Tl were used to compare the K+ transport properties in cell lines from human malignant gliomas (U-251MG and Tp-378MG), carcinomas, and brain metastasis. LÄS MER

7. 20. Conductance-based principles of neuronal firing and excitability

   Författare :Hugo Zeberg; Karolinska Institutet; Karolinska Institutet; []
   Nyckelord :;

   Sammanfattning : The brain is an electrical organ whose activity is determined by the flow of ions across cell membranes. As such, the conductances that control the ion flux is a key to our understanding of the nervous system. Neurons process information by their ability to rapidly depolarize and fire action potentials. LÄS MER