Question

In an experiment on synaptic transmission, a synapse was bathed in a Ca+2- free medium that was otherwise equivalent to extracellular fluid. An action potential was triggered in the presynaptic neuron. Although the action potential reached the axon terminal at the synapse, the usual response of the post synaptic cell, did not occur. What conclusion would you draw from these results? Explain your answer.

Answer 1

Response of the postsynaptic cell is dependent on the neurotransmitter release

Step-by-step explanation:

Calcium (Ca2+) is essential for the propagation of the action potential since it is required for neurotransmitter release. When an action potential reaches the end of an axon, voltage-dependent Ca2+ channels open and Ca2+ ions bind to regulatory proteins, thereby initiating the release by exocytosis of neurotransmitters contained in the presynaptic vesicles at the synapse and modulating the transmission of a signal to another neuron (i.e. the postsynaptic site).