What is the origin of 'sleep tight'?
Read moreOne of the mysteries of the English language finally explained.
Of, relating to, or designating neurons and neural pathways that utilize a purine, especially a purine nucleotide, as a neurotransmitter. Later also: of, relating to, or designating signalling of this nature between other types of cell.
1970s; earliest use found in The Courier-Mail. From purine + -ergic.