I'm getting confused about this test to further confirm the monosynaptic connection. I saw in some papers they used tetrodotoxin (TTX)-4-aminopyridine (4-AP) methods. EPSCs were abolished after bath application of TTX (1 mM) but were then reintroduced following bath application of 4-AP (100 mM; in the presence of TTX), a voltage-dependent potassium (K+) channel blocker. Could you explain to me how 4-AP can réactivate the inward current after blocking by TTX. It's a classical test? could someone explain to me the mechanism? How we can conclude that is a monisynaptic connection after applying this drugs?
Is it possibly that potassium blocking makes inside cell potential increase by K+ ion that can not go out from the cell?
Likely via depolarizing the axon terminal and activating voltage-gated calcium channels.
- Badges
- Science method