Describe what happens to neurotransmitters after they are released from the synaptic end bulb.
a) Neurotransmitters are broken down by enzymes in the synaptic cleft.
b) Neurotransmitters are reabsorbed by the presynaptic neuron through reuptake.
c) Neurotransmitters diffuse away and are absorbed by surrounding glial cells.
d) Neurotransmitters are transported back into the synaptic end bulb for reuse.