Neuro Foundation: Module 1.0 - 1.4 Flashcards
Who completed the orignal work for Patch clamp Electrophysiology?
Erwin Neher, Bert Sakmann, and Neher
What year did Erwin Neher and Bert Sakmann win the Nobel prize for their work on the patch clamp technique?
1991
What are 4 types of Ion channel gating?
- Ligand Gated
- Phosphorylation/ Dephosphorylation
- Voltage Activated
- Stretch/ Pressure Activated
What are 3 instances of inactivation for voltage-gated ion channels?
- Refractory Period
- Internal Incease of Ca2+
- Internal Increase of Ca2+ may cause dephosphorylation of the channel
Describe Purkinje Neuron morphology and where in the brain they are found.
- A vere large highly branched dentritic tree.
- Single Long Axon
- Found highly in the cerebellum.
Describe Cortical Neuron morphology and where in the brain they are found.
- Encompasses Pyrmadical neurons and Interneurons
- Most Abundant Class of neuron in the Cerebral Cortex
Describe Pyramidal Neuron morphology and where they are found in the brain.
- Most abundant type of Cortical Neuron
- Has a Pyramidal shaped cell body
- Highly Abdundant in Cortex yet also found highly in the Hippocampus
What are 3 different types of spiking patterns in neurons?
- Single AP
- Bursting
- Rythmically Bursting (Important in Locomotion and Respiration)
What is the term given to phospholipids to reference their hydrophobic and hydrophilic properties?
Amphipathic
At low concentrations in water what do phospholipids form?
Lipid Monolayer
At high concentrations in water what do phospholipids form?
Micelles and eventually lipid bilayers
What is the difference in permeability between a phospholipid bilayer and the plasma membrane?
-Phospholipid Bilayer - Impermeable barrier to Ions
-Plasma Membrane: Semipermeable to do protein transporters.
What are features of Lipid Rafts?
- Packed tightly with Sphingolipids
- Packed with cholesterol
- Raft does not disaccociate
- Has many Receptors and Proteins
- Need to move around membrane
What are 2 features that affect membrane fluidity?
- Saturated vs Unsaturated Fatty Acids
- Cholesterol Concentration
What is the equation that describes the simplest form of Diffusion?
Fick’s Law
Flux of Solute X (Jx) will depend on the Permeability of X (Px) multiplied by the difference in concentrations.
**Only works for Uncharged Particles **
What is the driving force?
Determines passive transport of solute against a membrane. Encompasses electochemical gradient and potential energy difference between the compartments and voltage difference if applicable.
What is the state of solute X when no net driving force is acting on it?
At Equilibrium
No Net Transport
What are the 4 modes of Transport across a membrane?
- Simple Diffusion
- Facilitated Diffusion
- Primary Active Transport
- Secondary Active Transport
What are 3 protein complexes that substances can use to cross membrane in facilitated diffusion?
- Pores: Channels that are always open
- Channels: Can be opened or closed by the action of specific mechanisms; Pores with gating mechanism
- Carriers: facilitate passive transport thrugh membranes; can be used in Active Transport
What are 4 examples of pores?
- Porins: Found in outer membrans of gram negative bacteria and mitochondria
- Perforin: Cytotoxic T lymphcytes use these glycoproteins to form pores on target cells to allow cytoplasm to leak out. Allow passage of all material killing target cell.
- Nuclear Pore Complex: Regulates traffic in and out of the nucleus
- Aquaporin: Pores that allow the passage of water
Pores are aqueous transmembrane conduits that are always open.
What are the 4 functional components of a channel?
- Gate: Conformation change determines whether channel is opened or closed
- Sensors: Can respond to signals (ligands, voltage, second messengers)
- Selectivity Filter: Determines the particular ions or classes of ion that have access to the channel.
- Open Channel Pore: Ions can flow passively through it until channel closes.
Channels are gated pores
Explain the transportation process of carriers.
What is the difference between the rate of transport (flux) between simple and facilitated diffusion?
Simple diffusion transport rate increases linearly with concentration and has no maximum.
Facilitated Diffusion has a limited number of proteins with set speed and will eventually reach a transport maximum.
What is an example of Primary Active Transport?
Sodium Potassium Pump
Why do we call the Na/K pump electrogenic?
Generates a -1 Charge intracellulary each cycle.
Explain the Enzymatic Cycle of the Na-K Pump.
Make sure to know the effect of Oubain on this pump
What are 2 different types of transporters used in Seconary Active transport?
- Symporters
- Antiporters