Neural signaling Flashcards
Type of signal neurons generate
electrical, based on flux of ions across cell membrane
Key concepts of electrical activity of neurons
- poor generator of electricity
- develop mechanisms to overcome this ( see #1) limitation
- electrical signals based on flux of ions across membrane
typical RESTING MEMBRANE POTENTIAL of neuron
-65 mV indicates that cell is not undergoing an AP
Depolarization phase of Action Potential
cell membrane potential becomes more positive due to influx of sodium
hyperpolarization phase of Action Potential
cell membrane potential becomes more negative due to efflux of potassium
difference between leaky and voltage-gated potassium channels
leak channel sets the resting membrane potential and are always open
voltage gated channel is cause of hyperpolarization and are not always on
How is an Action Potential accomplished by neuron/in neural signaling?
- Concentration or chemical gradients
2. selective membrane permeability ( based on electrical charge, voltage gated channels)
What is the membrane potential at the peak of an Action Potential
It is equal to the equilibrium constant of sodium, 60 mV
At rest, what is the membrane potential of a neuron ?
It is equal to the equilbrium constant of postassium,
Current is a function of ______
conductance
Conductance is _______ and ____________ dependent
voltage; time
Early current in an AP is driven by which ion?
sodium
Later current in an AP is driven by which ion?
potassium
Action potential threshold
is membrane potential ( Vm) at which the inward sodium conductance equals the outward potassium conductance
Nernst equation
used to determine equilibrium potential for for any one ion ( Eeq)
