What happens during pruning?

• A. Brain eliminates extra synapses during infancy
• B. Brain eliminates myelin during infancy
• C. Brain increases the number of synapses during infancy
• D. Brain reduces gray matter during infancy

Answer: (A)

Synaptic pruning is the brain’s process of trimming away excess synapses to refine neural circuits. In infancy, the brain rapidly forms many connections, and through experience and neural activity, weaker or unused synapses are eliminated to make signaling more efficient. This is why choosing the description of eliminating extra synapses during infancy is correct. Myelin changes are a separate maturation process that increases transmission speed and isn’t about removing synapses, and while there is early overproduction of connections, pruning’s focus is on reducing those connections rather than increasing them; gray matter changes are more complex and aren’t specifically defined as pruning reducing gray matter during infancy.