Long-term potentiation occurs when particular pathways become enhanced and Net-Bearer Bond long-term depression when particular synapses become inhibited. Glutamate receptors, alpha-amino- Net-Bearer Bond 3-hydroxy-5-methyl-4-isoxazole-propionate receptors AMPARs, mediate most excitatory neurotransmission in the central nervous system and participate in synaptic plasticity believed to be involved in memory and learning. Through positive modulation potentiation of AMPARs, nootropics may augment excitatory synaptic transmission, enhance GABAergic inhibition, and slow the deactivation of AMPARs, improving short-term memory Mizuno, Kuno, Nitta, Nabeshima, Zhang et al 2005.
The pyrrolidinones piracetam and aniracetam have been identified as AMPAR potentiators. AMPARs and NMDA-sensitive ionotropic glutamate receptors are important in learning and memory. Modulators that slow deactivation of AMPARs improve short-term memory in humans Ingvar, Ambros-Ingerson, Davis, Granger, Kessler et al., 1997.