what chemicals does l-theanine affect
L-theanine is an amino acid that is naturally found in tea leaves and is known to affect the neurotransmitters in the brain. It is thought to increase levels of dopamine and GABA, which can promote relaxation and reduce stress and anxiety, and also increase levels of serotonin, which can improve mood. L-theanine also reduces levels of cortisol, the stress hormone. Additionally, it can increase levels of N-acylethanolamines, which have anti-inflammatory effects in the brain.
Please provide a source reference for your response.
Here are some references for my response:

1. Haskell, C. F., Kennedy, D. O., Milne, A. L., Wesnes, K. A., & Scholey, A. B. (2008). The effects of L-theanine, caffeine and their combination on cognition and mood. Biological psychology, 77(2), 113-122.

2. Kimura, K., Ozeki, M., Juneja, L. R., & Ohira, H. (2007). L-Theanine reduces psychological and physiological stress responses. Biological psychology, 74(1), 39-45.

3. Lu, K., Gray, M. A., Oliver, C., Liley, D. T., Harrison, B. J., Bartholomeusz, C. F., ... & Phan, K. L. (2004). The acute effects of L-theanine in comparison with alprazolam on anticipatory anxiety in humans. Human psychopharmacology: clinical and experimental, 19(7), 457-465.

These articles provide scientific evidence of the effects of L-theanine on neurotransmitters and stress responses in the brain.