We request 5 days on Sandals to study the interactions of the neurotransmitters dopamine, L-dihydroxyphenylalanine and norepinephrine in aqueous solution. The interactions of the compounds with water molecules (in buffered solutions) will be assessed together with the conformations of the molecules. The results will be compared with the descriptors assigned to the 3D structure of the molecules using VolSurf which enables the blood-brain barrier permeability of a molecule to be predicted.