Neural communication Flashcards
How is neural communication measured and recorded?
Electrode inside and outside measures the difference in voltage
The difference in voltage is communication
communication between single neuron
- change in voltage
-chemica in nature
-manipulation
voltage
-electrical potential
-needs a coparison
- insode of cell to outside
-dif of about 70mV
chemical neural communication
moving ions around
- result of 2 ions (Na and K) moving around inplasma membrane
- ions move into or out of cell, but not freely
electrical neural communication
- ions are + and - charged
- leaves, leaving cell slightly more neg
- as they move in/out of cell, they change the potential at eh membrane (v)
id the ions important for neural communication, incl electrical properties
- K+ potassium and Na+ sodium, both are positively charged
gradient =
force
proteins of the resting membrane potential?
- sodium-potassium pump - ATP needed, 3 Na+ out, 2 K+ in
- potassium leak channels - req no E
channels
-passive
- ole, pore passageway
- sometimes general or distinct channels
-let Ma through but not K
pumps
- active transport
- transport from one side to another
- special situations:
- mvoe against concentraion gradient
-requires ATP
sodium potassium pumps
- constantly pumping K into, Na out
- 3NA out, 2 K in
- net negative of =1 per action
- slight negative gradient
-uses 2/3 of all brain ATP
-one door opens, other closes
-slower than channels - mechanistic
-most important protein in all neurons
-embedded in membrane always working
potassium leak channels
-req no energy
- more K in cell
- leak out (gradient)
- voltage = more neg
- embedded in membrane always working
note on chem and elec comm working otgether
- chemically, ions want to flow out (lots of K inside)
- this takes the + charge with it, making cell more negative
- there is now a negative for wanting to pull the ions back in
= balance = RMP
what is resting membrane potential? whys it important?
the balance between chemical forces and eqlectrical forces in the cell.
what happens if resting membrane potential (RMP) disrupted?
RMP, cells are?
polarized
-chem = push out
- elec = push in
RMP = equilibrium
at rest:
- lots of NA outside, can flow however it wants, K cannot
when an NT binds to a receptors, it can have one of two localized effects
- depolarize the membrane
- hyperpolarize the membrane
proteins invovle in maintaining RMP
NA+ channels, and K+ channels
IPSP
inhibitory post synaptic potential
- hyperpolarize
- decrease likelihood of AP
EPSP
excitatory post synaptic potential
- increase likelihood of AP
- depolarize the membrane
what are 3 qualities of post-synaptic potentials?
1 - graded ( bigger or smaller depending on how many NTs attach),
2 - rapid (instantaneous),
3 - decremental (degrades)
- can measure anywhere on whole neuron, but
- gets weaker along dendrite because its an uninsulated wire (non-myelinated)
describe 2 forms PSPS can take, their effects, and what causes them
- enough EPSPs = AP fires
what is an AP? where does it occur? what proteins cause it?
AP is ions moving across the membrane that causes a massive, brief reversal of the membrane potential
- it occurs along the neuron
- all or nothign phenomenon
- always the same size/shape, eg. not graded
- happens where voltage gated Na+ channels open
threshold potential
the point at which enough EPSPs can reach that guarantees an AP to fire
