Neurotransmitter degradation

1. Neurotransmitter diffusion vs. active transport (Nootropic Key Ideas)
2. Neurotransmitter synthesis vs. degradation (Nootropic Key Ideas)
3. Neurotransmitter synthesis vs. degradation pathways (Nootropic Key Ideas)
4. Neurotransmitter vs. Neuromodulator (Neuroscience Tips)