Lecture 3 and 4 Flashcards
Voltage clamp
manipulates voltage and measures changes in current.
Current clamp
manipulates current and measures changes in voltage.
Dynamic Clamp
manipulates resistance and measures the changes in voltage.
TTX
Found in puffer fish and blocks most, but not all voltage-gated sodium channels.
Qwilfish
Pokemon’s version of the puffer fish.
Where does an action potential start?
The Axon Hillock
What are the 5 steps in NT release?
- Action potential
- Depolarization of terminal
- Influx of calcium
- Vesicular fusion
- NT release
If passive current moves in both directions along an axon, why does an AP only move in one direction?
An AP only moves in one direction because the inactivation of the voltage-gated sodium channels pushes the potential in one direction.
Absolute refractory period
The time immediately after the sodium hyper polarization in which the voltage-gated sodium channels are then inactivated. CANNOT generate an AP.
Relative refractory period
Time in which it is HARDER to generate an action potential. Some Na+ voltage gated channels remain inactivated but some are open.
Saltatory Conduction
The propagation of action potentials along myelinated axons that makes them faster.
Oligodendroglia myelinate axons in the ___?
CNS
Schwann Cells myelinate axons in the ___?
PNS
Glial functions
- Can regulate the extracellular milieu. (buffer K+)
- Can influence AP propagation through myelination.
- Can direct the localization of membrane proteins in neurons, including ion channels.
SNARE Proteins
These proteins help to dock the synaptic vesicles in place in preparation for release of NT.
