Unused neural connections in the brain are reduced through a process of

Pruning or remodeling

Explanation:

The brain is the major control system of animals. It acts just like the processor in a computer system. Brain development starts before childbirth and progresses to adulthood.

During the first few year of life, the neural and synapse connection multiply by millions, when the brain is mature enough, the brain begins to cut off connections of synapses, neurons and axons that are not used through the process called pruning or remodeling, which is very vital for brain development.