The neurons in our brains switch between electrical and chemical signals to help us react to new challenges, figure out how to improve our responses, and remember how to do it again. Scientists have identified that the chemical neurotransmitters and the protein receptors to which they bind, lead to a conformational change in the protein receptor that opens up an ion channel to a flux of charged atoms, igniting the electrical signal. Scientist also focus on Cys-loop receptors as very important molecules that are involved in memory and sensory perception. Neutrotransmitters bind to members of the Cys-loop receptor family at a site consisting of five aromatic amino acids. When the neurotransmitter serotonin bind to a tryptophan residue in its neuroreceptor protein, a conformational change is induced that allows a distant proline residue to undergo a cis-trans isomerization, which helps the open channel in the flow of current across the membrane and thereby generate electrical signal.