AMPA receptors are a type of glutamate receptor found in the brain that play a crucial role in fast synaptic transmission. They are responsible for mediating most of the excitatory signals in the central nervous system. When glutamate, the primary excitatory neurotransmitter, binds to these receptors, it allows sodium ions to flow into the neuron, leading to depolarization and the generation of an action potential. These receptors are essential for various brain functions, including learning and memory. They are often studied in the context of synaptic plasticity, which is the ability of synapses to strengthen or weaken over time, a key mechanism underlying how experiences shape our neural connections.