Racetams
We cover a lot of material on the racetam class of drugs here at Corpina.org – and it’s for a great reason. They come in several forms, such as piracetam, oxiracetam and coluracetam to name a few. All of them appear to affect the actions of acetylcholine, which drives our short and long term memory. A boosted memory is one thing, but the racetams affect the systems of other receptors as well. For instance, piracetam has been observed to act on the NMDA glutamate receptors, which are associated with both learning and memory processes. Since both of these crucial factors for plasticity are covered, piracetam is a viable substance to aid in the learning of new subjects. Many followers of nootropics would agree, although piracetam doesn’t work perfectly for everyone.
from corpina.com article 
Many other nonpharmacologic methods have been shown to directly stimulate and maintain neuroplasticity. They include: Engaging in positive social interactions
Participating in novel activities
Engaging in play
Being in enriched and stimulating environments
Practicing and repeating positive activities—even mentally rehearsing them
Engaging in mental training strategies such as mindfulness meditation
Developing a sense of purpose in life.