Question

injection of the Ca2+ chelator 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA) in the vicinity of a synapse will inhibit neurotransmitter release without interfering with action potential generation or propagation to the synaptic terminal. Explain the process by which BAPTA inhibits neurotransmission

Answer 1

Answer: Injection of Ca²⁺ buffers with different rates of Ca²⁺ binding produces differential effects on transmitter release. Specifically, BAPTA, a rapidly binding chelator, efficiently blocks release of calcium. BAPTA inhibits the release if the calcium domain is hundreds of nanometer away. In case of BAPTA it can inhibit the release of calcium even if the calcium domain is tens of nanometer away from the calcium sensor. In this way BAPTA inhibits the neurotrasmission by inhibiting the release of calcium ion.