Harry Is Going to Mei's House to Feed Mei's Cat

Multiple Choice

Harry is going to Mei's house to feed Mei's cat while she is gone.Mei left Harry her key ring,but when Harry reaches the front door,he realizes he doesn't know which key fits the lock.He tries several before finding the right one.If we compare the key and the lock to the behaviour of communicating neurons,we can say that the key is like a __________________ and the lock is like a ________________________.

A) vesicle;synaptic space
B) neurotransmitter;receptor site
C) presynaptic neuron;vesicle
D) neurotransmitter;node of Ranvier