Final answer:
Synaptic pruning is the biological process by which the brain eliminates unused or unwanted neurons and synapses to streamline neural communication paths. This process is part of neural development and contributes to the brain's efficiency by removing synapses less likely to fire an action potential.
Step-by-step explanation:
The process by which unused or unwanted neurons and synapses are eliminated is known as synaptic pruning. This biological process occurs as the brain develops and matures, typically peaking during early childhood and again during adolescence. Synaptic pruning is crucial for the brain's development because it helps to strengthen important connections while eliminating weaker ones. This is part of the brain's way of becoming more efficient, as neurons and synapses that are less likely to fire an action potential are removed. This process can also be influenced by a person's experiences and environment, with those synapses being used more frequently becoming stronger and those that are neglected getting pruned away.
In the context of neurotransmission, once a neurotransmitter has managed to cross the synaptic cleft and bind to the receptors on the postsynaptic neuron, it must be cleared away to reset the synapse for a new signal. This is done through diffusion, enzymatic degradation, or reuptake. In the case of reuptake, the neurotransmitter is pumped back into the neuron that released it. Drugs that inhibit enzymes responsible for the degradation of neurotransmitters, such as acetylcholinesterase, increase neurotransmission by allowing neurotransmitters like acetylcholine to remain in the synaptic cleft for a longer period.