BFAE9A0Fd01 - Molecular signaling in the neuron General...

Info iconThis preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Molecular signaling in the neuron • General principles of cell signaling • Ion channels • Membrane potential • Synaptic transmission • Dopamine Molecular signaling in the Neuron – Molecular Biology of the Cell • Chapter 11: membrane transport of small molecules and the ionic basis of membrane excitability – Principles of Neural Science • Part II: cell and molecular biology of the neuron • Part III: elementary interactions between neurons: synaptic transmission – The Brain: a neuroscience primer by Richard Thompson – Understanding G protein-coupled receptors and their role in the CNS by Menelas, Pangalos and Davies – G protein-coupled receptors by George Vauquelin and Brengt von Mentzer – PubMed: articles
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 General principles of cell signaling Some definitions as we start A signaling cell produces a signal. The signal induces a response in the target cell. Signals are generally referred to as ligands (ligare - to bind). A generic term for a molecule that binds to specific sites on a protein. Ligands that stimulate pathways are called agonists. Ligands that inhibit pathways are called antagonists. General principles of cell signaling There are five types of receptor 1. Intracellular receptors. 2. Receptors that are ion channels. 3. Receptors with intrinsic enzyme activity. 4. Receptors linked to protein kinases. 5. Receptors coupled to target proteins via a G protein. Two types of receptors important in neuronal signaling 1. Receptors that are ion channels. 2. Receptors coupled to target proteins via a G protein: GPCRs
Background image of page 2
3 Ion channels Major function of neurons: communication – has to be fast and travel long distances – different types of neurons communicate different kind of information still, all information transmitted under same form: changes in electrical potential across plasma membrane of neurons ( b change in membrane potential = change in charge difference across the membrane (volt = V) Changes in electrical potential mediated via specialized class of proteins: ion channels Two classes of ion channels -Resting channels b generate the resting potential b underlie the passive properties of neurons -Gated channels b generate the action potential b responsible for the active currents b voltage-gated, ligand-gated and mechanically-gated channels
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
4 Ion channels: properties Three important properties of ion channels -Conduct ions -Fast: up to 100 million ions/second through one channel -Recognize and select specific ions -Open and close in response to specific electrical, mechanical or chemical signals Physical chemistry of ions in solution •PM highly impermeable to ions, energetically unfavorable for an ion to lose its water ions and move into hydrophobic layer •Specialized pores •Ion + shell of water = size
Background image of page 4
5 Selectivity of ion channels Chemical interactions and molecular sieving K+-leak channels conduct K+ 10.000 times better than Na+ Crystal radius K+: 0.133 nm, while crystal radius Na+: 0.095 nm, so not solely dependent on diameter pore Selectivity of ion channels Chemical interactions and molecular sieving
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 6
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 39

BFAE9A0Fd01 - Molecular signaling in the neuron General...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online