Researchers have identified a compound in tree bark that mimics the chemical reactions of a naturally occurring molecule in the brain responsible for stimulating neuronal cell signaling. The tree bark compound, known as gambogic amide, behaves much like Nerve Growth Factor, a molecule found in the brain. NGF binds to TrkA, a neuronal receptor, and activates neuronal signaling. It is known that the loss of TrkA density correlates with neuronal atrophy and severe cognitive impairment such as that associated with Alzheimer's disease.