AniracetamvsNoopept

Aniracetam is a positive allosteric modulator of AMPA receptors, binding to the allosteric site and slowing receptor desensitization, which prolongs excitatory postsynaptic currents and facilitates long-term potentiation. It also modulates group II metabotropic glutamate receptors (mGluR2/mGluR3), which regulate presynaptic glutamate release. Uniquely among racetams, aniracetam increases dopamine and serotonin release in the prefrontal cortex via modulation of monoamine transporter activity and vesicular release, contributing to its anxiolytic and mood-enhancing effects. It reduces GABAergic inhibition in the hippocampus through indirect modulation of GABA-A receptors, facilitating NMDA receptor activation and memory consolidation. The lipophilic phenylacetyl group enables rapid blood-brain barrier penetration.

Noopept modulates AMPA and NMDA receptors similarly to racetams through positive allosteric modulation. Its key distinguishing feature is upregulation of BDNF (brain-derived neurotrophic factor) and NGF (nerve growth factor) via activation of TrkB and TrkA receptor signaling cascades — these neurotrophins are essential for neuronal growth, survival, dendritic arborization, and synaptic plasticity. Noopept inhibits glutamate-induced excitotoxicity by reducing calcium influx through NMDA receptors and modulating the NR2B subunit. It activates the PI3K/Akt and MAPK/ERK pathways downstream of neurotrophin receptors. The active metabolite cycloprolylglycine (a cyclic dipeptide) has endogenous nootropic activity, potentially acting as a trace amine-associated receptor ligand. Neuroprotection is further mediated through antioxidant effects and mitochondrial stabilization.