Answer:
Gradually disappear
Step-by-step explanation:
Synaptic pruning occurs between early childhood and adulthood, during this process our brain gets rid of extra synapses.
Synapses are structures in brain that allows the neurons to transfer signals to other neurons, during synaptic pruning brain removes the connections in brain which is no longer required. It a way to maintain efficient brain function as we grow old and learn new complex information.