Neurons Flashcards
1
Q
Impulse conduction
A
- an AP causes an influx of Na+ across the membrane
- reversal is the source of depolarizing current in adjacent membrane
- AP propagates from origin across the rest of the cell
- immediate
2
Q
Vesicle release
A
- AP current opens Ca++ channels
- triggers cascade of reactions that result in exocytosis
- change is slow because of the enzyme activity
3
Q
Ionotropic effects
A
- ligand binding opens an ion channel
- causes a post-synaptic membrane potential (PSP)
- 20-40 ms
- cations = EPSP
- Cl- or K+ = IPSP
4
Q
Ionotropic Effect
A
Ligands are
- Ach
- glutamate
- GABA
- glycine
- receptor determines effect, not the transmitter
5
Q
Metabotropic
A
- G-protein coupled receptor activated
- increase production or destruction of 2nd messenger
6
Q
Spread of PSPs
A
- generated in inexcitable membranes by binding of transmitter
- graded potential (not AP)
- passive conduction
- magnitude lost over time
7
Q
PSP summation
A
- bad cable property
- potential is lost across the membrane
two types:
- spatial
- temporal
8
Q
spatial summation
A
10-30 EPSP generated at a different synapse
- graded potentials sum at trigger zone and generate an AP