I'm currently trying an experimental neuropeptide called FGL (FG Loop). It's a "neural cell adhesion molecule (NCAM)-derived fibroblast growth factor receptor (FGFR) agonist"
http://www.funakoshi.../FGLnoprice.pdf
http://www.alzforum.org/new/detail.asp?id=3075They report that FGL treatment stimulates activity-dependent delivery of glutamate receptors to synapses, leading to a long-term enhancement of synaptic transmission...
Importantly, enhanced synaptic transmission does not occur spontaneously after FGL treatment. Instead, the peptide seems to facilitate long-term potentiation (LTP) in response to synaptic activity. In FGL-treated hippocampal slices, electrical stimulation induced LTP nearly twice as strongly as in untreated slices, and inhibiting PKC prevented this effect. Furthermore, when the authors blocked NMDA receptors, which are crucial for LTP, FGL treatment no longer pumped up AMPA receptor delivery. Esteban notes that this activity dependence is critical for a cognitive enhancer. If the peptide indiscriminately increased synaptic transmission, it might overexcite neurons and lead to epilepsy, he said. But by heightening synaptic plasticity only in response to activity, the peptide helps the animal encode information more easily, leading to better memory.
Studies on FGL suggest that FGL improves the brain's ability to modify brain cell connections; and that neurons treated with FGL show that they had higher levels of the receptor AMPA - critical for modifying synapses.
So far (~10 days) I am seeing some pretty amazing results. I'm taking 250mcg x 2 daily. It may sound outlandish, but I do feel like my brain is becoming more 'plastic': learning seems easier, and I am experiencing a definite lift of mood. It does have to be injected under body fat (like Cerebrolysin), however.
I've been told by a company who has conducted their own "in-house" studies that receptor down-regulation and tolerance is not an issue.
If anyone is looking for a source, you can find it online. I'd prefer not to directly link anyone on this thread, but if you're having trouble finding it you can PM me.