Final answer:
The neural basis for learning and memory due to brief, rapid stimulation at synapses is known as Long-term Potentiation (LTP), which is a strengthening of synaptic connections following activation of NMDA receptors and the addition of AMPA receptors. Long-term Depression (LTD) is the reverse process, where synaptic connections are weakened by the removal of AMPA receptors, helping to prune unnecessary connections.
Step-by-step explanation:
The neural basis for learning and memory, found at the synapses in memory-circuit connections, resulting from brief, rapid stimulation is called Long-term Potentiation (LTP). LTP is crucial for synaptic plasticity, which is the brain's ability to strengthen or weaken synapses. This process follows the Hebbian principle that neurons that fire together wire together. LTP occurs when NMDA receptors on the postsynaptic neuron become activated due to depolarization by repeated stimulation, allowing Ca²⁺ ions to flow in. This triggers the insertion of AMPA receptors into the postsynaptic membrane. These additional AMPA receptors increase the synaptic strength, enhancing the response of the postsynaptic neuron to future stimuli.
In contrast, Long-term Depression (LTD) is the process of synaptic weakening. LTD involves the removal of AMPA receptors from the synapse after a decrease in calcium influx due to a low presynaptic firing rate. This synaptic weakening plays a role in pruning out less used connections, thus refining and optimizing neural circuits for better efficiency of memory storage and recall.